1 Year 8 n 3 Autumn 2011 SPECIAL SUPPLEMENT EASIT2: a Competence Framework for the Analysis and Simulation Industry Simulare ed ottimizzare il processo di stampaggio a freddo di viterie Reducing Emissions of PCDD/F in Sintering Plant: Numerical and Experimental Analysis Performance termo-fluidodinamiche e d illuminazione di due tipologie di lucernari EnginSoft Contributes to the Reduction in Aircraft Engine Fuel Consumption (Project ERICKA) Earth Breathing in Response to Underground Gas Storage Revealed by InSAR Measurements and Predicted by a Transversally Isotropic Geomechanical Model EnginSoft Interviewed Mr. Matteo Cova, Engineer at SACMI
3 Newsletter EnginSoft Year 8 n 3-3 EnginSoft Flash At EnginSoft, we are where our customers are. While we offer several different technologies and complementary services, we always keep the big picture in mind: the needs of industry and the accuracy, reliability, applicability of the different software products. During the year, our experts screen existing and new technologies. We are always up to speed and want to provide only the best to our customers. At the same time, we constantly adapt our consulting, support and training offers to have a most complete service package in place for the user. Ing. Stefano Odorizzi EnginSoft CEO and President Articles this time include a case study on reducing emissions of PCDD/F in a sintering plant and the use of modefrontier as a numerical and experimental analysis tool. Prof. Giuseppe Gambolati of University of Padova outlines earth breathing in response to underground gas storage. We hear about the impact of thermo-fluid-dynamics in the development of industrial lighting and the impact on heating, ventilation and costs. Our in-depth study describes cold forging simulation and process optimization with ColdForm. Gruppo Ferroli inform us about their use of MAGMASOFT and MAGMAfrontier. Our software news features the Forge 2011 Release Notes. Once a year, the EnginSoft International Conference and the ANSYS Italian Conference bring together all this knowledge, engineering expertise and software know-how to a melting-pot where our customers update us on what they expect from the software vendors, from EnginSoft and ANSYS! This Newsletter gives a Conference preview: We ask our readers to refer to the overview of the technical talks that will be presented on 20th and 21st October. The list of speakers is growing day by day. The program contains many highlights and outstanding topics from users from industry, the academia and research. Our Plenary Session features presentations from highlyesteemed keynote speakers who will update us on the global use and importance of CAE today. A Geomodelling Workshop complements the opening part of the program. It will highlight, among other themes, the geological deposition of sedimentary basins and their reconstruction, challenges that are of paramount importance to identify areas which can potentially host hydrocarbon reservoirs in the future. The program also offers a Workshop on Eco Building and how CAE technologies nowadays support the integrated design of sustainable buildings. A third workshop addresses the Design of Structures with Composite Materials. This Edition presents announcements of our Conference Sponsors to pre-inform our readers on the state-of-the art software and hardware products which will be showcased in the exhibition. We update our readers on EnginSoft s role in the ERIKA and EASIT2 Research Projects and our collaboration with NAFEMS for the latter. Our interview this time presents Mr Cova, Engineer at SACMI and some of his views on innovation and CAE. We report from the 12th International Summer School on Light Alloys Castings and look out on the next seminars and conferences with our Event Calendar. Recently, the Trends & Challenges in Computational Mechanics-TCCM 2011 Conference took place in Padua, in Honor of Professor Peter Wriggers 60th Birthday. Our readers are invited to hear more about one of the world s leading scientist in this field on the following pages. The Japan Column informs us about the CDAJ Numerical Analysis Academy, a seminar program that delivers the highest quality technical information to modefrontier Users in Japan. We also learn about the spirit of WA in the Japanese culture and the importance of teamwork and community effort. these thoughts also accompany our team while closing this Edition and preparing for the Conference on 20th and 20st October. EnginSoft and ANSYS Italy look forward to welcoming you to Verona! Let us share our knowledge and enthusiasm for CAE, simulation and innovation! Stefano Odorizzi Editor in chief
4 4 - Newsletter EnginSoft Year 8 n 3 Sommario - Contents CASE STUDIES 6 Reducing Emissions of PCDD/F in Sintering Plant: Numerical and Experimental Analysis 15 Performance termo-fluidodinamiche e d illuminazione di due tipologie di lucernari RESEARCH & TECHNOLOGY TRANSFER 19 EnginSoft Contributes to the Reduction in Aircraft Engine Fuel Consumption as a Partner of the FP7 European Project ERICKA 21 EASIT2: a Competence Framework for the Analysis and Simulation Industry IN DEPTH STUDIES 23 Earth Breathing in Response to Underground Gas Storage Revealed by InSAR Measurements and Predicted by a Transversally Isotropic Geomechanical Model 26 Esperienze di simulazione di stampaggio a freddo di acciaio con presse automatiche multi stazione: l ottimizzazione di processo come strumento per ottenere le migliori prestazioni e la massima qualità SOFTWARE NEWS 34 FORGE 2011 Release Notes TESTIMONIAL 37 FERROLI: Passione, Professionalità, Dedizione INTERVIEWS 38 EnginSoft Interviewed Mr. Matteo Cova, Engineer at Sacmi JAPAN CAE COLUMN 40 CAE Seminars in Japan, CDAJ Numerical Analysis Academy 41 和 WA - Exploring the True Meaning The EnginSoft Newsletter editions contain references to the following products which are trademarks or registered trademarks of their respective owners: ANSYS, ANSYS Workbench, AUTODYN, CFX, FLUENT and any and all ANSYS, Inc. brand, product, service and feature names, logos and slogans are registered trademarks or trademarks of ANSYS, Inc. or its subsidiaries in the United States or other countries. [ICEM CFD is a trademark used by ANSYS, Inc. under license]. (www.ansys.com) modefrontier is a trademark of ESTECO srl (www.esteco.com) Flowmaster is a registered trademark of The Flowmaster Group BV in the USA and Korea. (www.flowmaster.com) MAGMASOFT is a trademark of MAGMA GmbH. (www.magmasoft.de) ESAComp is a trademark of Componeering Inc. (www.componeering.com) Forge and Coldform are trademarks of Transvalor S.A. (www.transvalor.com) AdvantEdge is a trademark of Third Wave Systems. (www.thirdwavesys.com) LS-DYNA is a trademark of Livermore Software Technology Corporation. (www.lstc.com) SCULPTOR is a trademark of Optimal Solutions Software, LLC (www.optimalsolutions.us) Grapheur is a product of Reactive Search SrL, a partner of EnginSoft (www.grapheur.com) For more information, please contact the Editorial Team
5 Newsletter EnginSoft Year 8 n 3-5 EVENTS 43 TRENDS & CHALLENGES IN COMPUTATIONAL MECHANICS: A Conference in Honour of Peter Wriggers 60th Birthday 45 12th International Summer School on Light Alloys Castings: from Innovative Design to Advanced Applications 46 Seminario sulla Tomografia Computerizzata 48 EnginSoft Event Calendar ENGINSOFT INTERNATIONAL CONFERENCE 2011 CAE TECHNOLOGIES FOR INDUSTRY ANSYS ITALIAN CONFERENCE 2011 SPECIAL SUPPLEMENT ENGINSOFT CAE CONFERENCE 2011 PAGE 6 REDUCING EMISSIONS OF PCDD/F IN SINTERING PLANT: NUMERICAL AND EXPERIMENTAL ANALYSIS PAGE 23 EARTH BREATHING IN RESPONSE TO UNDERGROUND GAS STORAGE REVEALED BY INSAR MEASUREMENTS AND PREDICTED BY A TRANSVERSALLY ISOTROPIC GEOMECHANICAL MODEL Newsletter EnginSoft Year 8 n 3 - Autumn 2011 To receive a free copy of the next EnginSoft Newsletters, please contact our Marketing office at: All pictures are protected by copyright. Any reproduction of these pictures in any media and by any means is forbidden unless written authorization by EnginSoft has been obtained beforehand. Copyright EnginSoft Newsletter. Advertisement For advertising opportunities, please contact our Marketing office at: EnginSoft S.p.A BERGAMO c/o Parco Scientifico Tecnologico Kilometro Rosso - Edificio A1, Via Stezzano 87 Tel Fax FIRENZE Via Panciatichi, 40 Tel Fax PADOVA Via Giambellino, 7 Tel Fax MESAGNE (BRINDISI) Via A. Murri, 2 - Z.I. Tel Fax TRENTO fraz. Mattarello - Via della Stazione, 27 Tel Fax COMPANY INTERESTS ESTECO srl TRIESTE Area Science Park Padriciano 99 Tel Fax CONSORZIO TCN TRENTO Via della Stazione, 27 - fraz. Mattarello Tel Fax EnginSoft GmbH - Germany EnginSoft UK - United Kingdom EnginSoft France - France EnginSoft Nordic - Sweden Aperio Tecnologia en Ingenieria - Spain ASSOCIATION INTERESTS NAFEMS International TechNet Alliance RESPONSIBLE DIRECTOR Stefano Odorizzi - PRINTING Grafiche Dal Piaz - Trento The EnginSoft NEWSLETTER is a quarterly magazine published by EnginSoft SpA Autorizzazione del Tribunale di Trento n 1353 RS di data 2/4/2008
6 6 - Newsletter EnginSoft Year 8 n 3 Reducing Emissions of PCDD/F in Sintering Plant: Numerical and Experimental Analysis The sintering operation in integrated steelworks is one of the main sources for the production of polychlorinated dibenzop-dioxins, polychlorinated-dibenzo-furans, NO x and SO x. In the present study, the operating conditions, through which a reduction in emissions can be achieved, were defined through numerical analysis. The following process parameters were evaluated: gas temperature, quantities of chlorine and copper and additions of hydrated lime, sulphur and urea. Using the optimization software modefrontier, a virtual surface that can reproduce the actual process of sintering was created. Moreover the application of filtering to postsintering gas, such as electrostatic precipitator and wetfine scrubber, yielded a reduction in emission values down to the limits stated by the international protocol Aarhus. Keywords: Iron ore sintering, Dioxin emission, Numerical analysis, Process optimization List of symbols Cl chlorine rate CO carbon monoxide CO2 carbon dioxide rate Cu copper rate DoE design of experiment DOF design objective function ESP electrostatic precipitator Lim maximum value of the output min. minimum value of the output MOGA multiobjective genetic algorithm MOGT multiobjective games theory Moi moisture NOx nitrides NSGAII non-dominated sorting genetic algorithm O2 oxygen rate PCDD polychrorinated dibenzo-p-dioxins PCDF polychrorinated dibenzo-furans rate air flowrate RS response surface S Sulphur rate SOx sulphides Twbox windbox temperature Twleg windleg temperature TCDD 2,3,7,8,-tetrachlorodibenzo-p-dioxin TEF toxic equivalency factor TEQ toxicity equivalent Wb windbox number WS wetfine scrubber Introduction Process description The process of sintering to improve the physical and chemical properties of iron ore for use in blast furnaces is well documented [1 5]. The agglomeration process gives rise to many different physical and chemical phenomena. During heating, the following main steps can be distinguished: around 100 C, drying of the mixture; at higher temperatures, the water of crystallization is removed between 600 and 800 C, the first agglomeration of fine particles into a porous material takes place, and the swelling grains adhere weakly to each other above 1000 C, the grains soften, and the physical and chemical conditions lead to the completion of the agglomeration process. At the end of the grate, a sinter breaker reduces the sintered material to the desired size . Here, PCDD/Fs form in the presence of carbon containing materials [7,8]; the process is favoured by the presence of specific organic compounds or a carbonaceous matrix sand source of chlorine and oxygen, plus increased temperatures ( C; at higher temperatures, PCDD/Fs will rapidly decompose). It was observed that the presence of catalytic metals (Cu) can be essential at modest temperatures . In the sinter bed, basically three layers can be recognized: raw material (wet and cold), the burning front and the cool down zone, consisting of sintered material. In this region, the products of incomplete combustion surviving the heat of the burning front may condense, while the temperature is high enough to enable reactions with species in the raw materials acting as catalysts. Furthermore, the native carbon containing materials may react via the so called de novo route. During sintering, conditions are encountered wherein dioxins can be formed and, for some parts, survive . Emission formation The gas temperature inside the windbox and windlegs is lower ( C) compared to the sintering grate; such conditions lead to the optimal physical and chemical conditions for the formation of pollutants, such as PCDD/F, NOx and SOx . Both PCDDs and PCDFs are persistent stable organic pollutants formed in all those high temperature processes with an abundance of organic material in the presence of chlorine and copper. Dioxins and furans are chlorinated tricyclic organic compounds resulting from the
7 Newsletter EnginSoft Year 8 n 3-7 combination of organic compounds impregnated with halogens (i.e. fluorine, chlorine, bromine or iodine) with a specific molecular heterocyclic structure . A deep and complete thermodynamic description of the PCDD/F formation has been presented by Tan et al . These compounds are commonly grouped under the name dioxins, but their chemical structures and their properties can be very different. Dioxins are a class of heterocyclic organic compounds whose basic structure consists of rings with four carbon and two oxygen atoms. On the other hand, furans have only one oxygen atom (Fig. 1), and the two outer benzene rings are linked by a pentagonal structure. Among the 200 types of Multiobjective analysis In the present study, a broad range of processing parameters affecting the development of PCDD/Fs in the sintering process has been evaluated. The main aim was the possible reduction of dangerous emissions through numerical and experimental analysis, allowing the definition of the optimal conditions for the minimisation of pollutants. The employed multiobjective optimisation software is modefrontier, Fig. 1 - Polychrorinated dibenzo-p-dioxins/dibenzo-furans structure Fig. 3 - modefrontier (mf) operative optimization flow Fig. 2-2,3,7,8,-tetrachlorodibenzo-p-dioxin structure known dioxins, the most famous are certainly the PCDD, characterised by the presence of chlorine atoms that will complement the aromatic rings. The chemical stability of such compounds derives from the presence of these rings. The most dangerous of dioxins, for serious problems of bioaccumulation and environmental contamination, is certainly TCDD (Fig. 2). A detailed description of their formation is presented in the literature [14-16]. The PCDDs are generally measured in terms of TEQ relative to TCDD as a reference, being the most polluting and dangerous. The poly dibenzo-dioxins have different toxicities in relation to their structure. The TEQ expresses the quantity of a toxic substance as the concentration of the reference substance that can generate the same toxic effects of TCDD. It is also possible to obtain the concentration of a PCDD with its toxic equivalency through the use of the TEF. The TEF for TCDD is assigned equal to 1, while the other dioxins have a factor of <1. This dimensionless parameter, multiplied by the actual concentration, results in the TEQ. The World Health Organization has identified the seven most toxic PCDDs and the 10 most toxic PCDFs, giving them an international toxic equivalency factor (equation (1)) through which a set of input parameters, governing the plant and the production process, were defined. They were evaluated on the basis of an optimization algorithm chosen for the multiobjective analysis (Fig. 3). Starting from a database, built by employing experimental and literature data, a computational model (n-dimensional virtual surfaces) capable of reproducing at best the actual process was developed. The analysis performed led to the minimization of the output variables (PCDD/F, NOx and SOx). For PCDD/F, it was necessary to apply a filtering system in Fig. 4 - Workflow of analysis
8 8 - Newsletter EnginSoft Year 8 n 3 Fig. 5 - Dioxin emission in sintering plan monitored in present study: data are compared with levels indicated by Aarhus protocol17 and European legislation order to obtain quantities of emissions below the legal limit of 0. 4 ng I-TEQ/N m 3 as required by the Aarhus protocol required by the Aarhus protocol [17 21]. Experimental and numerical procedure Work definition The sintering process is outlined in the workflow through the analysis carried out by modefrontier, as shown in Fig. 4. The workflow is divided into data flow (solid line) and logic flow (dotted line), which have a common node, i.e. the calculator node, in which mathematical functions and chemical reactions representative of the process are introduced. In the data flow, all the input parameters are Tab. 1 - Example of database grouped; such input parameters should be optimized during numerical simulations as a function of the multiobjectives (in the present case, the reduction of emissions). In the present case, the following input parameters are considered and then introduced: number of the windbox: progressive value that indicates in which windbox there was a known level of emissions; gas temperatures in the windbox and windlegc percentage of O 2, CO 2, CO and Moi inside the windbox that affects the development of PCDD/F 22 ; exit gas rate (in m s -1 ): it appears to be an important parameter because it defines how long the gas remains within the windbox ; Cl and Cu: both elements improve the production of PCDD/F, although in different ways; chlorine is a key component of the structure of PCDD/F, and depending on the number of atoms on the rings, it defines the hazards and toxicity; copper is a strong catalyst and thus fosters a series of chemical reactions, leading to the development of PCDD/F [19,20]; addition of S, according to the following three ways: through gas SO2 added to the combustion gases, by the addition of coal containing sulphur with more impact than the previous case of pollutants SO 2, in the form of sulphur based reagents added to crude oil ; addition of urea, which has a dual effect of inhibition: it can act on the urea functional groups by blocking some surface complexes and thereby reducing the availability of catalytic metal sites and can coat the surface of the particulates and prevent chemical reactions [25-28]; addition of hydrated lime: capable of increasing the economic productivity of sintering; it is demonstrated to be a good suppressor of PCDD/F [29-31]; normally, HCl reacts with oxygen to form water and Cl 2 ; the lime reduces the atmosphere of chlorination by setting HCl in CaCl 2, which has the lowest vapour pressure between the various metal chlorides . The analysis of the sintering process was performed on a sintering plant (Dwight-Lloyd) belonging to an Italian steel company. The emissions levels in the past years before the study are shown in Fig. 5 and compared with the Aarhus protocol and the European legislation. Each windbox was equipped with thermocouples (k type) in order to monitor the off-gas temperature during sintering. The flue gas composition was monitored according to EN1948 parts 2 and 3, EN1948 SS (sampling standards, Wellington Laboratories), EN1948ES (extraction standards, Wellington Laboratories) and EN1948IS (injection standards, Wellington Laboratories) by employing a high resolution gas chromatograph and a high resolution selective mass detector. The output variables (PCDD/F, NO x and SO x ) define a multigoal analysis and have been minimized, taking into account some constraints or limitations typical of the actual process of sintering. At this stage, the nodes that make up the logic flow of numerical analysis are defined. The first node is the DoE, which is a set of different designs reproducing different possible working conditions, among which the most effective ones are highlighted. Therefore, it means creating a set number of designs that will be used by the scheduler (the node where the best algorithm is introduced) for the optimisation. Depending on how this space is filled, the designs, defined by the scheduler, are more or less truthful. Therefore, the choice of the DoE is to
9 Newsletter EnginSoft Year 8 n 3-9 be assessed correctly. In the present case, an appropriate method of assessment proposed by mode FRONTIER was used, i.e. reduced factorial. This method is characterised by the independence between all the considered variables, and it allows the creation of a space design that can start covering all the different possible configurations and more easily achieve the optimum. The second node filters the input experimental data; the filtering is possible by employing three types of different algorithms. Such algorithms are MOGA II, MOGT and NSGA II. The MOGA is set to obtain a fast convergence to the Pareto curve, supports the geographic selection and directional crossover and allows the simultaneous assessment of independent design. The MOGT is based on the competitive game theory by Nash linked to the simplex algorithm. It is particularly suitable for studies with many constraints, highly non-linear objectives. It finds a compromise solution (Nash equilibrium) from a small number of rating points. The NSGA II is based on the crossing over method. The different performances of all the available algorithms were analyzed; NSGA II was found to be the most suitable for this kind of study. The main reasons are the possibility to analyse a large number of input parameters and to produce a series of designs able to investigate all the possible combinations of input parameters in a broad range of conditions. A number of generations equal to 10 or 100 (depending on the test) and a probability of crossover equal to 0. 9 were set. The main features of the NSGA II are the following: the allowance of continuous (real code) and discrete variables (binary code); allowing user defined discretization; the method of handling constraints does not use the parameter penalty; the implementation of elitism for multiobjective research; the diversity and distribution of the solutions are guaranteed without the use of sharing parameters; the allowance of the competitive assessment of the n independent variables. Multiobjective analysis By continuing the analysis, the core work flow is defined, which, in the present case, is a specific RS, which proves to be the only node common between logical and data flow. Generally, in this kind of analysis, the heart of the optimisation is represented by a series of equations of chemical and physical nature of a given resolution to get the desired output. In the present case, all this information is not clear due to the complexity of the process, and so it was decided to employ the methodology of response surfaces. Optimization software allows the following different kinds of RS. For each output variable to be minimised, it is necessary to create a response surface. The analysis starts from a database built with data of operating conditions of the sintering plants obtained from experimental measurements and other related values found in the literature. Fig. 6 - NOx, SOx, dioxin versus windbox and temperature Database construction The database was built by introducing the input parameters, the corresponding output for each working condition experimentally analysed and the physical correlations between the different conditions. The global employed database consists of 578 different designs; an example of input and output parameters is shown in Table 1. Of the 578 starting designs, 572 were used to generate metamodels, while six designs were employed as designs of control to verify the affordability of the response surfaces. The choice of these six was taken in order to get the right
10 10 - Newsletter EnginSoft Year 8 n 3 Fig. 7 - NOx, SOx, dioxin versus urea and windbox information on the entire range of existence of the output variables. The designs of control are the following: ID=126; low value of PCDD/F, low NO x, SO x low ID=184, average value of PCDD/F, low NO x, SO x high ID=269, average value of PCDD/F, low NO x, SO x average ID=346; low value of PCDD/F, high NO x, SO x low ID=501; high value of PCDD/F, low NO x, SOx low ID=534, mean PCDD/F, high NO x, SO x low. In the present study, six response surfaces that are best suited to deal with multiobjective optimization were obtained. The six response surfaces are a function of the chosen response surface. The characteristics of each family of RS are as follows. Single value decomposition (SVD) is the simplest method for Fig. 8 -NOx, SOx, dioxin versus hydrated lime and windbox generating a surface, and with this method, it is possible to choose the degree of the polynomial interpolation with which the different information can build a virtual model. Radial basis function (RBF) is a powerful tool for the multivariate interpolation of scattered data. The term scattered data means that the points of training should not be sampled on a regular grid because RBF is a correct method without the use of mesh. Since the RBF interpolant is a response surface, it passes through the points of training. With this method, a policy of fully automatic scaling based on the minimization of the mean leave one out is implemented. Through a scale parameter, the shape of the radial function can be determined. The leave one out method is an effective way to control the efficiency of interpolating a response.
11 Newsletter EnginSoft Year 8 n 3-11 information on the error between the created surface and the real distribution of the starting design. In this way, it was possible to find the average and maximum relative and absolute error, regression and principal value of the error. Tab. 2 - Input parameters Tab. 3 - Windbox optimum design no. 19 Neural network (NN) is one of the most powerful and efficient methods of interpolation. Inspired by the structure and functions of the human brain, NNs can learn from a training set proposed by the user. The interpolating function is usually a sigmoid function. An NN may generate non-linear relationships between input and output variables. The network that is generated consists of a sequence of hidden layers of neurons allowing the creation of relationships between input and output variables. One of the problems occurring with the use of NNs is overfitting. The next step is to evaluate the performance surface and use them as a node operator in our workflow. The available tools are the ones offered by modefrontier, such as the response surface methodology (RSM) distance, the RSM residual and the RSM function plot. Initially, the tool RSM distance, allowing to assess graphically the distance between the real values provided by the database and those generated by the virtual meta-model, was employed. The virtual profile is very close to that of the actual design but, in some cases, cannot reflect it perfectly. The difference is greater with respect to the SVD surfaces. The situation improves with the NN. At first glance, using such a tool, the best Dioxin_RBF_0 and Dioxin_NN_1 were found, but in this case, a more detailed analysis is necessary. With regard to the NO x variable, the same kind of analysis was performed. The two SVD surfaces cannot play the best sequence of real design. It can be concluded, then, that the choice falls on the type RBF or NN, which are more efficient. In addition, for the SO x, the same kind of analysis was performed. The surface SO x _SVD_0 cannot cover the design that has a high value of SO x, and it behaves better in the case of a design with smaller values. This leads to the formation of a poor surface for higher values of this parameter. This first analysis led to the realization of how poorly performing the SVD_0 surface for all three output variables was, but not to narrow the field to the point of making a safe choice. Therefore, the second tool provided by mf or residual RSM was employed. This provides graphical and numerical Optimization procedure For the areas related to PCDD/F, the numerical value of the regression is about the same (close to 0. 99). For the mean error, the order of magnitude is 10-3, except for areas where NN_1 e RBF_0 decreases to At this point, they must be considered the maximum and average error, both absolute and relative. The maximum error is the same for all RS, improving slightly as it rises from the SVD to the NN. Instead of evaluating the average error, the known lowest values are those of the RBF surfaces that decrease to orders of magnitude of 10-2 /10-3. Observing the error, both absolute and relative, the surface method appears to be the most powerful. By performing the same analysis on the NO x variable, it was observed that the poorer areas are the SVD with residual high values. Furthermore, it shows how the lowest levels of residues are those of the two surfaces of RBF type. The most powerful, at least limited to this tool, seems to be the surface NO x _RBF_0. Finally, the same analysis was made to the output SO x variable. In the same way, it was found that the best is the SO x _RBF_0. The last tool to be used is the RSM plot function, which allows us to understand how the surface reconstructs a pattern of the three outputs as a function of the input variable. After the analysis of all the areas carried out through three different tools proposed in the design space of the mf panel, the optimal condition of the analysis can be chosen for each of the three output variables. The choices are the following: PCDD/F5Dioxin_RBF_0 NO x 5NO x _RBF_0 SO x 5SO x _RBF_O The choices lead to the use of RBF type surfaces with the MultiQuadrics Hardy s radial function. In fact, by looking at a distance, only the RSM distance and the RSM plot function, the RBF surfaces are very good. The contribution of residual RSM leads to the choice of RBF_0 permanently. At the beginning of the analysis, modefrontier generates the space of DoE following the Tab. 4 - Emissions of three best designs
12 12 - Newsletter EnginSoft Year 8 n 3 Tab. 5 - Parameters fixed for all windboxes Tab. 6 - Temperature fixed in windboxes and windlegs reduced factorial method. Then, these designs are transformed by the NSGA II algorithm. The new designs created by mf fill all the ranges of analysis. These designs are introduced in the response surface that has been set in the first step of the study. In this way, the mf generates a determined number of working parameters, which lead to a particular emission value. At this point, the user has to choose the set of input that produces the lower emission value for each output, considering the physical constraints and the legal limit. Results and discussion Before starting to analyse the results of numerical simulation, the influence of input parameters should be evaluated. Concerning the gas temperature in the windbox and windleg, it must be noted that their trends are very similar and differ only from 30 to 50 C; the last box can reach even higher temperatures, up to C. As shown in Fig. 6, the PCDD/F distribution has the maximum value around windbox no. 19, while the amount of emissions remains low in the first part of the sinter bed and in the end. When the gas temperature is higher than 500 C, the amount of PCDD/F is reduced. For NOx emissions, the maximum value is in windbox no. 7, while the maximum value of SOx is in windbox no. 16. The role of sulphur in the reduction of emissions in the sintering can be noted. In all three ways previously observed, there has been a reduction of PCDD/F, especially in the Fig. 9 - CO2, O2, CO and moisture versus windbox second case, and it is probably due to the presence of SOx in flue gas. It is believed that these sulphides can be converted to SO2, reducing the chlorine in HCl. The influence of urea is very important in the reduction of polluting emission. In particular, the emissions levels are reduced as the urea levels increase. For the PCDD/F, it occurs by means of physical deposition or by poisoning the catalytic sites (Fig. 7). A positive finding of urea in the reduction of SOx and NOx emissions, by up to 32 and 15% respectively, was also noted. The importance of lime in the reduction of PCDD/F should be outlined when it is introduced in the raw material. The emission levels are reduced as the lime quantity in the raw materials increases. The lime also brings a reduction of NOx from 16 to 30% of initial value and up to over 70% for SOx in particular working conditions (Fig. 8). Table 2 summarises the range of existence of all the input parameters analysed in the present study. The range of existence of any input parameter is characterised by chemical and physical constraints that have to be respected to obtain realistic results from the analysis. For example, the gas temperature in the windbox has to be higher than C because, at this point, PCDD/Fs begin to decompose, but at the same time, the temperature should not increase too much because the process would become too expensive. Cu and Cl have to be reduced, but there are physical and technological constraints that have to be respected by limiting the reduction of such elements in the raw material. Urea, sulphur and hydrated lime lead to a reduction of emissions, but too large an amount of these leads to the deterioration of the mechanical and technological properties of the sintered material. If the sulphur percentage rises, then the amount of SOx increases. For this reason, some designs have been excluded from the analysis. During the preliminary analysis of the training database, the windbox with the highest level of emissions was noted to be no. 19, so the first analysis was performed only on that windbox to look for a set of values to be assigned to the different parameters in order to reduce the production of PCDD/F, NOx and SOx. With the numerical simulation by mf software, a series of operating conditions for the sintering process has been defined. However, not all the numeric strings have produced low amounts of emissions. In some cases, the value is low for PCDD/F but very high for the other output, NOx and SOx. It is very important to consider all the aspects of the physical process. The user has to analyse the different sets of parameters and the output values reached, and he has to choose the best operating conditions. From the list offered by the first step of analysis, with numerical simulations, the three most suitable designs have been proposed because these lead to the minimum value of PCDD/F, NOx and SOx. Such optimum designs are summarised in Table 3. It should be noted that in all these cases, there are high values of oxygen, while those of monoxide and carbon dioxide and moisture are relatively low.
13 Newsletter EnginSoft Year 8 n 3-13 Tab. 7 - Emission values Tab. 8 - Radial basis function and ED emission Tab. 9 - Emission with filter devices The gas temperatures in the windbox turn out high; the chlorine and copper values are low, while the levels of additives cover upper middle values. Maximum emissions of SOx and NOx are found in windbox nos. 17 and 7 respectively. When sulphur rises, the level of SOx emissions increases, while the increase in the lime addition leads to a reduction in the levels of NOx and PCDD/F emissions. At this point, the best operating conditions of all the 21 windboxes of the system were fixed, and the medium value, weighed in the three different cases, was estimated. Some parameters, such as lime, sulphur, urea, chlorine and copper, remain similar for all the 21 windboxes, while the remaining input (temperatures, moisture, oxygen, etc.) assumes different values according to the position in the sintering bed . In Table 4, the values of the emissions for the different designs are summarised. In all three cases, the medium values of emissions of SOx and NOx are largely below the legal limit indicated by the international protocol Aarhus. Unfortunately, with such operating conditions, the PCDD/F levels still exceed the value limit of 0. 4 ng I-TEQ/N m 3. In addition to offering minimal value in the optimisation regarding windbox no. 19, design 1 proposes valid operating conditions for the whole system and the lowest values of pollutants. In order to define the optimisation strategy, reference to design 1 was chosen. The process parameters, which result independent from the position on the belt conveyor, were fixed. They are shown in Table 5. For the remaining process parameters, the choice of the values to apply to the single windbox is necessary. The results offered from the first phase of optimisation were not followed because the proposed profiles are discontinuous and inhomogeneous and difficult to apply to a real system. Therefore, another set of more homogenous profiles was proposed taking into account the data of the first phase of analysis, which is defined as new design (Fig. 9). At last, the temperatures of the windboxes and windlegs for the new design were chosen and are shown in Table 6. With these values attributed to the input variables, the minimum value of emissions obtained can be discovered. In Table 7, the results of the different designs are compared. Some of the optimal operating conditions were removed in favour of profiles easier to apply to the system. Consequently, an increase in the medium levels of emissions can be expected. In fact, the level of PCDD/F was found to vary from to ng I-TEQ/N m 3, with also a contemporary increase in NOx and SOx. With the exception of the latter, the PCDD/F still exceeded the legal limits. Despite an increase in emissions, the application of the set of parameters of the new design was chosen because it is technologically simpler to realise. In addition, a parallel analysis method was carried out. This method is based on the evolutionary design (ED). This allowed the extrapolation of a mathematical function from each of the three RS, with which the real system is reproduced. These functions are less realistic than RS. In Table 8, the values obtained with the two methods of calculation were compared. This study made it possible to implement a setting of the system through which it is possible to obtain a clean reduction of the emissions of polluting substances. Thus, just acting on input parameters, all the values of PCDD/F below the legal limit were not possible to achieve. A further possible improvement was studied, which consists of the application of a determined filtered device that can carry a further reduction of pollutants . The employed devices were as follows: ESP: Such a device is used mainly in order to collect and control particles produced in metallurgical systems [35,36]. The operation of this device is based on the application of a strong electric field ( V) through which particles contained in the exit gas are forced to pass. Successively, these run through a wide series of collection slabs, with opposite sign charges, which block such polluting particles; WS: this device contributes to reduce the emissions of PCDD/F in vapour form. The device makes possible the reduction of emissions by means of a two stage process: the first consists of the passage through a quenching unit, i.e. the scrubber, and the second is the passage through an electrostatic precipitator. The objective of our work is to understand how much these devices can be influential in the reduction of polluting emissions. In Ref. 37, the ESP and a more complex system like WS in a typical sintering system were analysed. Since, in the study, there are some small differences regarding the system considered in this analysis, a safety value of reduction was assumed, limiting the efficiency of the devices analysed in Ref. 37. We assume the following values of efficiency: ESP Reduction PCDD/F=40% WS Reduction PCDD/F=65% Reduction SOx=5%
14 14 - Newsletter EnginSoft Year 8 n 3 Consequently, applying such reductions to the values obtained from our numerical simulations, we succeed in obtaining the values of emissions shown in Table 9. Table 9 summarises the choices carried out and the final values obtained. It should be noted that the filtering device does not have an influence on the reduction of the NO x, but this turns out negligible as we are already within legal limits thanks to the choices made in the input parameters. The main situation is identical for the values of SO x ; even with WS, they are reduced by 5%. The reduction obtained from the PCDD/F emissions is the key aspect of the present study. In the event of the application of the ESP, the emission value is ng ITEQ/N m 3, while in the second case, the value is ng I-TEQ/N m 3, largely below the legal limit set in 31 December Conclusions Using the optimization software modefrontier (ESTECO), a virtual surface that can reproduce the actual process of sintering was created. Optimization of the sinter raw mix and, in particular, the operation of windbox no. 19, the main source of emissions, resulted in a 10-fold reduction in dioxins, but they were still marginally above the legal limit. The use of post-sintering scrubbers or precipitators reduced emissions to below the legal maximum. The NO x and SO x levels were below the legal maxima even without scrubbing or recipitators. References  M. Nakano, K. Morii and T. Sato: ISIJ Int., 2009, 49,  D. Senk, H. W. Gudenau, S. Geimer and E. Gorbunova: ISIJ Int., 2006, 46,  E. Aries, D. R. Anderson, R. Fisher, T. A. T. Fray and D. Hemfrey: Chemosphere, 2006, 65,  C. Xhrouet and E. de Pauw: Environ. Sci. Technol., 2004, 38,  L. Hsieh: ISIJ Int., 2005, 45,  D. R. Anderson and R. Fisher: Chemosphere, 2002, 46,  S. P. Ryan and E. R. Altwicker: Environ. Sci. Technol., 2004, 38,  N. Tsubouchi, S. Kuzuhara, E. Kasai, H. Hashimoto and Y. Ohtsuka: ISIJ Int., 2006, 46,  T. Kawaguchi, M. Matsumura, E. Kasai, Y. Ohtsuka and H. Noda: Tetsu-to-Hagane, 2002, 88,  M. K. Cieplik, J. P. Carbonell, C. Munoz, S. Baker, S. Kruger, P. Liljelind, S. Marklund and R. Louw: Environ. Sci. Technol., 2003, 37,  A. Iosif, F. Hanrot and D. Ablitzer: Environ. Imp. Assess. Rev., 2008, 28,  N. Menad, H. Tayibi, F. Garcia Carcedo and A. Hernandez: J. Clean. Prod., 2006, 14,  P. Tan, I. Hurtado, D. Neushutz and G. Eriksonn: Environ. Sci. Technol., 2001, 35,  P. S. Kulkarni, J. G. Crespo and C. A. M. Afonso: Environ. Int., 2008, 34,  K. Raghunatan and B. K. Gullet: Environ. Sci. Technol., 1996, 30,  K. Suzuki, E. Kasai, T. Aono, H. Yamazaki and K. Kawamoto: Chemosphere, 2004, 54,   M. Altarawneh, B. Z. Dlugogorski, E. M. Kennedy and J. C. Mackie: Prog. Energy Combust. Sci., 2009, 35,  P. Tan and D. Neuschutz: Metall. Trans. B, 2004, 35B,  S. Kasama, Y. Yamamura and K. Watanabe: ISIJ Int., 2006, 46,  Gazzetta Ufficiale Italiana, 2005,  M. Nakano, Y. Hosotani and E. Kasai: ISIJ Int., 2005, 45,  C. E. Loo and M. F. Hutchens: ISIJ Int., 2003, 43,  H. Ogawa, N. Orita, M. Horaguchi, T. Suzuki, M. Okad and S. Yasuda: Chemosphere, 1996, 32,  M. Lee: C-S-A China Steel Tech. Rep., 2001, 15,  M. Nakano, Y. Hosotani and E. Kasai: ISIJ Int., 2005, 45,  E. Kasai, S. Kuzuhara, H. Goto and T. Murakami: ISIJ Int., 2008, 48,  M. Boscolo and E. Padoano: Ironmaking Steelmaking, 2008, 35,  Y. C. Chen, P. Tsai and A. Luhmou: Environ. Sci. Technol., 2009, 43,  M. Nakano, K. Morii and T. Sato: ISIJ Int., 2009, 49,  V. M. Kurkin, M. S. Tabakov, E. A. Kashkarov, M. A. Gurkin, T. V. Detkova and S. V. Reshetkin: Metallurgist, 2007, 51,  M. Boscolo and E. Padoano: Ironmaking Steelmaking, 2011, 38,  T. Maeda, C. Fukumoto, T. Matsumura, K. Nishioka and M. Shimizu: ISIJ Int., 2005, 45,  N. Schofield, R. Fisher and D. R. Anderson: Ironmaking Steelmaking, 2004, 31,  E. Kasai, T. Aono, Y. Tomita, M. Takasaki, N. Shiraishi and S. Kitano: ISIJ Int., 2001, 41,  E. Kasai, Y. Hosotani, T. Kawagichi, K. Nushiro and T. Aono: ISIJ Int., 2001, 41,  E. Guerriero, A. Guarnieri, S. Mosca, G. Rossetti and M. Rotatori: J. Hazard. Mater., 2009, 172, P. Cavaliere, A. Perrone, P. Tafuro University of Salento, Department of Innovation Engineering For more information: Pasquale Cavaliere - University of Salento Vito Primavera EnginSoft
15 Lighting and Thermo-Fluid Dynamics: Vertical Opening vs Side-opening Skylights In order to benefit from environmental resources, high efficiency energy buildings are characterized by integrated architectural solutions. Naturally illuminated and ventilated working areas are healthier and make people feel better. Yet, if architects and engineers want to be efficient and successful in these areas, they have to analyze different and conflicting facts. While wide windows guarantee lots of good light and ventilation, it is important to protect people and objects from heat and the sun to avoid discomfort. These problems should be addressed early in the planning phase by using integrated design solutions, e.g. it is important to study wall and roof exposure prior to choosing window shapes, dimensions and materials. Basso Luce e Aria is an Italian company with 40 years of experience in the design and production of solutions for bringing natural light and air into homes and offices. Nowadays, the company has widened its offer: their technical teams use mathematical models in order to design healthier, more comfortable and energy efficient environments. Basso Luce e Aria collaborates with EnginSoft to evaluate the lighting and thermo-fluid dynamics of two of their skylight models: ALIDARIA ADR with vertical opening, fig. 1, and ARCODARI ACL with side opening, fig. 2. The computational analysis performed by EnginSoft reveals that while both devices, ALIDARIA ADR and ARCODARI ACL, provide good light incidence, ALIDARIA ADR ensures better ventilation. Newsletter EnginSoft Year 8 n 3-15 Performance termo-fluidodinamiche e d illuminazione di due tipologie di lucernari Fig. 1 Basso Luce e Aria: Lucernari ad apertura verticale (ALIDARIA ADR) Fig. 2 Basso Luce e Aria: Lucernari ad apertura laterale (ARCODARIA ACL) La realizzazione di un edificio energeticamente efficiente passa attraverso la scelta di soluzioni tecniche che, integrandosi nell architettura, permettono di massimizzare lo sfruttamento delle potenzialità climatiche locali. Un ambiente di lavoro illuminato e ventilato naturalmente è più salutare e produce effetti benefici sulle persone, migliorandone anche l operatività. L obiettivo di garantire il benessere di chi vive e opera all interno dei fabbricati comporta l esame di aspetti diversi e talvolta tra loro contrastanti. Ampie finestrature consentono da un lato il lavoro dell individuo in ambienti adeguatamente e naturalmente ventilati ed illuminati, dall altro obbligano a proteggere coloro che si trovano negli ambienti dal notevole carico termico che l irraggiamento solare produce e dai fenomeni di abbagliamento e di discomfort locale. Si tratta quindi di un problema di progettazione integrata da affrontare fin dalle prime fasi della progettazione, con un opportuna scelta del tipo di finestratura, delle dimensioni e della forma delle aperture, dei materiali impiegati e dell orientamento dell edificio stesso. Basso Luce e Aria ha quarant anni di esperienza nell affrontare problematiche di questo tipo. La progettazione e la produzione di soluzioni che portano luce ed aria naturali in ambienti per l edilizia industriale, commerciale e civile rappresentano il core business aziendale. Oggi quest azienda vuole offrire di più. Sfruttare modelli matematici per studiare ambienti più confortevoli, salutari ed energeticamente efficienti. Si collocano in questo contesto gli studi condotti per la valutazione dell illuminazione e delle performance termo-fluidodinamiche di due diverse tipologie di lucernari prodotti dalla Basso Luce e Aria: Lucernari ad apertura verticale (ALIDARIA ADR) e Lucernari ad apertura laterale (ARCODARIA ACL) (vedi Figura 1 e Figura 2). Analisi Illuminazione Una delle caratteristiche principali che rende preferibile la sorgente solare rispetto ad altre è la sua maggior resa cromatica (cioè come i colori appaiono sotto varie fonti di luce). Inoltre la radiazione visibile proveniente dal sole e dal cielo aggiunge una naturale dinamica alle condizioni d illuminazione di un ambiente, attraverso le variazioni temporali di colore, contrasto e luminanza di ogni superficie. La disponibilità di luce naturale, però, a differenza di quella artificiale, non può essere controllata e fissata dal progettista: la sua distribuzione e la sua intensità sono in funzione della stagione e della latitudine considerate. La geometria degli spazi e le caratteristiche fotometriche dei materiali giocano un ruolo fondamentale nel determinare la distribuzione spaziale e la qualità della luce in un ambiente, poiché le caratteristiche della luce disponibile su un piano di lavoro dipendono fortemente dalla geometria, dalla morfologia e dalle proprietà dei vari materiali incontrati dalla radiazione luminosa nel percorso dalla sorgente al piano di utilizzazione. Il flusso luminoso incidente su un materiale viene, infatti, in parte trasmesso, in parte riflesso e in parte assorbito. I raggi luminosi che attraversano l apertura trasparente, inoltre, incidono sulle diverse pareti che delimitano l ambiente e da queste vengono in parte assorbiti e in parte riflessi con una nuova varia-
16 16 - Newsletter EnginSoft Year 8 n 3 Tabella 1 Proprietà ottiche e termiche delle lastre dei lucernari Fig. 3 Modello geometrico zione della distribuzione spettrale e della direzione dei raggi luminosi. Vista la complessità dei calcoli richiesti per la valutazione dell illuminamento naturale in ambienti confinati, l uso di programmi di calcolo automatico basati su modelli tridimensionali dell edificio appare come la soluzione più idonea per la verifica della qualità dell ambiente luminoso nella fase di progetto. L analisi numerica è stata condotta prendendo a riferimento un edificio industriale a pianta quasi quadrata con lato di 75 m circa e altezza prossima agli 11 m. La pianta è smussata sul lato NE e la zona produttiva confina a SE con la palazzina degli uffici, che in queste analisi viene considerata solo come volume ombreggiante. Sulla copertura, di tipo piano, sono installati 21 lucernari di tipo ADR con lastra esterna color opale e velatura interna (vedi Figura 3). Fig. 4 Lucernari con velario Tabella 2 Illuminamenti calcolati per la configurazione con lastra esterna opale e velario trasparente Dal punto di vista illuminotecnico, le geometrie dei lucernari del tipo ad apertura verticale e laterale praticamente si equivalgono. Il livello di illuminazione (trasmittanza luminosa) e la quantità di calore trasmesso (conduttanza termica) variano in funzione del materiale e dello spessore delle lastre e della presenza di eventuali velature (vedi Figura 4 e Tabella 1). La complessità del problema affrontato dipende principalmente dall elevato numero di variabili che influiscono sulla determinazione dello stato d illuminamento dell ambiente interno. Le analisi sono state eseguite utilizzando il software per la simulazione in regime dinamico della risposta degli edifici EnergyPlus*, corredato dalle facilities della BENIMPACT Suite** di EnginSoft. Per l analisi illuminotecnica è necessario realizzare il modello tridimensionale dell edificio (alle cui superfici vanno attribuite adeguate proprietà ottiche), e disporre dei dati orari locali relativi all illuminamento su superficie orizzontale per le componenti globali, diffuse e dirette. È possibile conoscere, ora per ora, come si comporta il flusso luminoso entrante nell edificio al variare delle stratigrafie dei lucernari e calcolare il livello d illuminamento interno di una griglia di punti posta a 80 cm dalla pavimentazione del capannone, quota convenzionale dei piani di lavoro. Nel caso di assenza di velario al di sotto dei lucernari vi è un eccessivo irraggiamento nelle ore centrali della giornata. Le simulazioni hanno permesso di individuare come soluzione ottimale la configurazione con lastra esterna color opale e velario interno trasparente, che garantisce una miglior diffusione della luce. Si riportano di seguito le mappe che riportano i valori di illuminamento orario medio mensile per i mesi di gennaio e luglio (vedi Tabella 2) e una tabella di intervalli di riferimento (vedi Tabella 3). Si fa presente che, rispetto ai valori di illuminamento presentati (vedi mappe della tabella 2), quelli calcolati in assenza di ve-
17 Newsletter EnginSoft Year 8 n 3-17 fra loro strettamente connessi: il numero di ricircoli aria per ora e le temperature medie nel capannone. Il primo indice rappresenta il numero di volte che il volume d aria interno al capannone viene rinnovato ad ogni ora grazie all ingresso di aria proveniente dall atmosfera. I risultati mostrano come le performance del Lucernari ad apertura verticale siano nettamente superiori (+33%). Il maggior ricambio d aria assicurato dai lucernari ad apertura verticale si traduce in un valore più favorevole del secondo in- Tabella 3 - Intervalli di illuminamento in funzione dei compiti visivi lario sono del 50% superiori, mentre quelli con velario opale sono del 40% inferiori. Inoltre, l isolamento termico dei lucernari aumenta installando il velario, ma non è influenzato in maniera significativa dal suo colore. La scelta della stratigrafia del lucernario da installare dipende quindi dall analisi combinata delle prestazioni energetiche globali e di comfort luminoso desiderate. Analisi Termofluidodinamica I lucernari sono tra i principali attori nella regolazione dei flussi energetici di un edificio da e per l ambiente esterno. Un lucernario performante dal punto di vista termo-fluidodinamico favorisce la movimentazione della massa d aria presente nell edificio mitigandone le condizioni climatiche. Di qui la necessità di un attenta progettazione di tali dispositivi e l esigenza di studiarne il comportamento fluidodinamico tramite un modello matematico. La simulazione numerica dei campi termici e del moto d aria all interno di un edificio è infatti in grado di fornire importanti indicazioni sull efficienza termica dell edificio stesso. Nel caso specifico, l analisi numerica è stata condotta prendendo a riferimento un capannone industriale di dimensioni standard (Superficie pianta 960 m 2 e Volume m 3 ). La superficie finestrata apribile del capannone è stata decisa sulla base del regolamento edilizio che prevede una metratura pari ad almeno 1/20 della superficie di pianta equamente distribuita fra lucernari e finestre apribili a parete. In accordo con la normativa sono stati installati sul tetto del capannone 4 lucernari da 6[m 2 ] ciascuno e sulla parete 4 finestre con apertura a vasistas anch esse da 6[m 2 ] ciascuna (vedi Figura 6). Due sono gli scenari presi in considerazione: il primo prevede l installazione di soli lucernari ad apertura laterale ed il secondo di soli lucernari ad apertura verticale. La geometria dei lucernari e le relative dimensioni sono state ricavate dai disegni tecnici forniti da Basso Luce e Aria. Ciò ha permesso un maggior dettaglio e realismo nello studio della fluidodinamica locale in prossimità delle regioni di efflusso dell aria (vedi Figura 7 e Figura 8). Il confronto è stato eseguito a parità di condizioni al contorno (direzione ed intensità del vento, apertura finestre a parete) ed ai fini di un analisi quantitativa sono stati considerati due indici termo-fluidodinamici Basso Luce e Aria: Lucernari ad apertura laterale (ARCODARIA ACL) Fig. 5 - Configurazione con velario trasparente Fig. 6 Modello geometrico per analisi CFD con lucernari ad apertura verticale installati sul tetto del capannone Basso Luce e Aria: Lucernari ad apertura verticale (ALIDARIA ADR) Fig. 7 Campo di velocità in prossimità dei lucernari su di un piano che taglia longitudinalmente i lucernari lungo la linea di mezzaria. La mappa colore mostra l intensità del campo mentre i vettori ne indicano la direzione. E possibile notare come il lucernario ad apertura verticale ha una maggiore capacità di estrarre aria ed una minore tendenza a creare ricircoli nel capannone.
18 18 - Newsletter EnginSoft Year 8 n 3 le ore in cui è necessario accendere l illuminazione artificiale. Si è inoltre dimostrato che l installazione dei velari riduce i rischi di abbagliamento e di eccessivo irraggiamento nelle ore centrali della giornata. La scelta della stratigrafia di lucernario da installare dipende quindi dall analisi combinata delle prestazioni energetiche globali e di comfort luminoso desiderate. Basso Luce e Aria: Lucernari ad apertura laterale (ARCODARIA ACL) Lo studio termo-fluidodinamico ha mostrato come il lucernario ad apertura verticale è potenzialmente in grado di migliorare l aerazione del capannone rispetto ad un modello di lucernario più tradizionale ad apertura laterale. Il sistema ad apertura verticale, tipico del lucernario ALIDARIA ADR, riduce gli ingombri e massimizza il numero di ricircoli d aria per ora. In conclusione, i lucernari ad apertura verticale (ALIDARIA ADR) sono da preferirsi poiché hanno prestazioni luminose pressoché analoghe a quelle dei lucernari ad apertura laterale (ARCODARIA ACL), ma migliorano l aerazione del capannone. Le immagini di Figura 1, Figura 2, Figura 4 e Figura 5 sono state cortesemente concesse da BASSO FRANCO Srl Via Ragazzi del 99 n Fontaniva (PD) Tel.: Fax: Basso Luce e Aria: Lucernari ad apertura verticale (ALIDARIA ADR) Fig. 8 Vettori velocità in prossimità dei lucernari su di un piano che taglia trasversalmente i lucernari nella zona dei sostegni. L efflusso d aria del lucernario ad apertura verticale è meglio distribuito e presenta picchi di velocità inferiori. dice. La temperatura media osservata all interno del capannone (34.7[C]) è infatti inferiore (-10%) rispetto a quella misurata nelle medesime condizioni per lo scenario con i lucernari ad apertura laterale installati (vedi Figura 9). *Energy Plus è un software per la simulazione termica e la diagnosi energetica in regime dinamico degli edifici distribuito da Lawrence Berkley National Laboratory. L algoritmo di calcolo su cui si basa l analisi illuminotecnica di questo programma è stato formalizzato per la prima volta nel 1985 dai ricercatori F. Winkelmann e S. Selkowitz. ** Il prototipo di BENIMPACT Suite è stato sviluppato nell ambito del Progetto di Ricerca BENIMPACT Buildings ENviromental IM- PACT evaluator & optimizer cofinanziato dalla Provincia Autonoma di Trento utilizzando risorse del Programma Operativo FESR PARTNERS Basso Luce e Aria: Lucernari ad apertura laterale (ARCODARIA ACL) Da osservare infine come la condizione di vento studiata (direzione frontale al lucernario) è da considerarsi la condizione più sfavorevole per il lucernario di tipo ad apertura verticale. È presumibile che, in condizioni di vento differenti (vedi per esempio una condizione con vento diretto lateralmente al lucernario), le performance dello stesso risultino ancora più favorevoli. Conclusioni L utilizzo di modelli matematici ha permesso di valutare le performance di illuminazione ambiente e termo-fluidodinamiche di due diversi tipi di lucernari. Dal punto di vista dell illuminazione, le analisi eseguite hanno permesso di verificare che entrambe le tipologie di lucernari riescono a soddisfare i requisiti di illuminamento sul piano di lavoro per buona parte della giornata. Questo riduce notevolmente Basso Luce e Aria: Lucernari ad apertura verticale (ALIDARIA ADR) Fig. 9 Distribuzione della tempeartura all interno del capannone su di un piano che taglia longitudinalmente i lucernari lungo la linea di mezzaria
19 Newsletter EnginSoft Year 8 n 3-19 EnginSoft Contributes to the Reduction in Aircraft Engine Fuel Consumption as a Partner of the FP7 European Project ERICKA key aims of the EU, which set the goal in its report European aeronautics: a vision for 2020, of Europe becoming the uncontested world leader in aeronautics by The challenge The combustion processes involved in aero-engines and gas turbine for electricity production contribute to deteriorate air quality and to alter the concentration of greenhouse gases. Two factors are principally responsible for this degradation: carbon dioxide (CO 2 ), for which aviation and energy consumptions currently account respectively for 3% and 27%, and nitrogen oxides (NO X ). To ensure a clean, sustainable growth in air traffic and energy production, new gas turbine technologies need to be developed. The efficiency of a gas turbine depends directly on the performance of all its components. One of the most important is the turbine, whose efficiency has a great influence on engine fuel consumption, therefore CO 2 emissions. The turbine must operate at high efficiency despite being subjected to the engine s most aggressive heat loads (the working fluid supplied to this stage is at the cycle peak temperature). Thus, the design of turbine cooling systems is one of the most challenging processes in engine development. ERICKA (Engine Representative Internal Cooling Knowledge and Application) is a European project within the Seventh Framework Programme, partly funded by the European Commission. ERICKA intends to face the challenge of reducing CO 2 and NO X emissions by improving engine efficiency through innovative turbine cooling technologies. The Consortium The project, coordinated by Rolls-Royce, involves 18 partners (beneficiaries): 7 gas turbine manufacturers (Rolls-Royce plc, Alstom, Avio, ITP, MTU, Rolls-Royce Deutschland, Snecma) 5 SMEs (CENAERO, Cambridge Flow Solution, EnginSoft, NUMECA, ARTTIC) 5 universities (University of Florence, Universidad Politécnica de Madrid, University of Oxford, Universität Stuttgart, Polish Academy of Science) 1 research organisation (ONERA) Nearly all of the leading European Aircraft engine manufacturers are partners in ERICKA: this satisfies one of the The concept New turbine blade cooling technologies will be studied within ERICKA. The work is a combination of experimental activities, which include tests both in stationary and rotating facilities (like the Rotating Heat Transfer Rig by Rolls-Royce, shown in Figure 1), and computational activities, performed using CFD analysis and by design optimization (see Figure 2). New designs will be developed using expertise of the engine manufacturers, understanding of flow physics derived from both the experiments and the CFD predictions, together with the results of optimization campaigns. The objectives Today's environmental issues and economic conditions constantly push aero-engine manufacturers to improve the efficiency of their engines in order to reduce fuel consumptions. With these premises ERICKA targets the reduction of greenhouse gas emissions from aircraft engines and power generation plants: the main objective is to cut CO 2 emissions by 1% compared to year 2000 reference engines. For turbomachinery, reducing CO 2 relates directly to improving component s efficiency. This enhancement could be achieved by combining a more efficient cooling system, which requires a reduced amount of cooling air, and raising the gas turbine entry temperature. Unfortunately, NO X emissions also increase with the inlet gas temperature, leading to a conflict between the environmental targets. This further problem could be overcome by re-distributing the cooling air saved in the turbine to the combustor, where it can be used to lower peak flame temperatures, thus allowing a reduction in NO X emissions. Such improvement of the turbine efficiency aims to a 1% reduction in specific fuel consumption. For a large turbofan engine, this translates into a saving of 450 litres of fuel per hour. The project aims to improve engine efficiency by setting the following operational objectives: 1. Creation of a database of detailed heat transfer coefficient (HTC) data from a broad range of stationary internal blade cooling geometries. 2. Acquisition of engine representative rotating HTC data for the validation of the cooling system design methods of the aero-engine manufacturers.
20 20 - Newsletter EnginSoft Year 8 n 3 3. Development of the CFD strategies to predict complex internal flows. 4. Development of optimizing procedures for internal cooling based on the measurements made in (2). 5. Experimental evaluation of optimized results. 6. Development of cooling system design methods suitable for future low emission and green fuel combustors. 7. Implementation of the improved cooling systems in future aero-engines, dissemination in the supply chain and communication to the aerospace sector through technical publications. Another important objective is related to time and cost savings. The improved modelling and computer methods that come out of ERICKA are targeted at reducing the time to design the turbines by 20%. This will reduce engine cost significantly and create a competitive supply chain able to halve time to market. The role of EnginSoft ERICKA offers EnginSoft an important opportunity to bring its contribute to make significant advancements in the cooling technology used in the design of future aero-engines. Thanks to its wide expertise on CFD and optimization, EnginSoft will work closely with Avio (industrial partner) in the development and optimization of the leading-edge impingement concept design for internal cooling. ERICKA project is split into five technical work-packages. Each of them is focused to a particular critical aspect of internal flow and heat transfer in blades for both high pressure (HP) challenges, like the development of parametric techniques to allow the exploration of different designs of turbine blade internal cooling components, as well as the automation of the simulation loop. A typical CFD optimization procedure involves the linking of geometric design, meshing tool, CFD solver run and postprocessing. All these simulation processes need to be handled in parametric and full automated way; for this reason they are well suited to be integrated in an ANSYS Workbench workflow, which offers a comprehensive view of the entire analysis project, a simple way to pass files and data from one application to the other, and a powerful tool to manage the parameter set. In turn, the resulting ANSYS Workbench project will be integrated into a workflow under the control of ESTECO modefrontier. A careful choice of input ranges, output quantities, objectives and constraints, together with multiobjective search algorithms will allow a quick and complete exploration of the parameters space. The role of the optimization algorithms is to identify the solutions which constitute the best available design lying on the Pareto Frontier curve, whose points represent solutions having the characteristic that none of the objectives can be improved without prejudicing another. Objectives will be related to wall heat transfer (specific per unit area, specific per unit mass flow rate, uniformity, etc.). WP5: CFD calculations This task represents the nexus of the experimental and computational activities performed in the other technical work-packages. For each experimental WP, the industrial partners involved will perform a validation campaign of the available CFD solvers. The objective is to find a numerical methodology able to well fit the experimental results, principally acting on turbulence modelling and meshing strategies. Another important result expected in this task is the estimation of the errors to be taken into account in the optimization process. Figure 1: the Rotating Heat Transfer Rig (RHR) is one of the few facilities in the world that is able to accurately simulate High Pressure turbine cooling passage conditions by simultaneously matching engine Reynolds number, buoyancy number and rotation number. Figure 2: EnginSoft will deal with the leadingedge impingement concept design developed by Avio. The results of the CFD analysis will be combined with experimental ones to better understand the complex internal flows. turbine and low pressure (LP) turbine applications. The partners will collaborate to perform each task within and across the work-packages, as internal cooling geometries design, prototyping, manufacturing, testing, CFD modelling, and optimization. In particular, EnginSoft is involved in 2 work-packages (WP): WP1: Optimization of turbine cooling system components. The optimization task includes several significant It is interesting to notice that all of the engine companies will be involved in CFD tasks. Their work will be integrated by studies performed by specialists in fluid flow and heat transfer simulation to improve their computer modelling strategies. In this way, ERICKA will ensure that the analysis and optimization procedures developed by SMEs, like EnginSoft, will be used by the gas turbine community to enhance Europe s future aeroengines. Acknowledgments The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/ ) under grant agreement n (ERICKA). For further details, please visit ERICKA s website: