Development of a Propulsion Model for a MDO Framework: Mission-Based Optimization

Development of a Propulsion Model for a MDO Framework: Mission-based Optimization José Ricardo Teixeira Fernandes Thesis to obtain the Master of Science Degree in Aerospace Engineering Supervisors: Prof. Fernando José Parracho Lau Dr. José Lobo do Vale Prof. Michele Ferlauto Examination Committee Chairperson: Prof. João Manuel Lage de Miranda Lemos Supervisor: Prof. Fernando José Parracho Lau Member of the Committee: Prof. Filipe Szonolky Ramos Pinto Cunha November 2015 ii In thrust we trust. iii iv Acknowledgments I would like to start by expressing my gratitude to my supervisor Professor Fernando Lau, for all his support and careful attention on reading and correcting the drafts of my thesis. Also to him and to Professor Afzal Suleman for the possibility of working in this project. To my co-supervisor Dr. Jose´ Vale and to Dr. Frederico Afonso I am grateful for constant attention and availability for helping on every single difficulty as well as contributing to the good working environment that they created right from the first moment. My gratitude to my supervisor Professor Michele Ferlauto from the Politecnico di Torino for his review on the work developed and for its support on dealing with all the paperwork and bureaucracy needed for finalizing the thesis at PoliTO. Then a special thanks to Jose´ Oliveira, with whom I could share closely this thesis work development and who was always the first helping source for any difficulty. Also to David Brandao˜ which in a later phase helped me by reading and correcting my drafts. Lastly, I would like to express my gratitude to my family for their unconditional support and care along this complete journey and to my friends for all the good moments. v vi Resumo As regulamentaçoes˜ ambientais impostas a` industria´ do transporte aereo´ cada vez mais restritivas, aliadas as` previsoes˜ de crescimento deste sector, temˆ imposto uma grande pressao˜ sobre o desen- volvimento de aeronaves com um consumo de combust´ıvel cada vez menor. Para dar resposta a estes requisitos contraditorios,´ o projeto de novas aeronaves tem estado a desenvolver-se para que, desde os primeiros estudos preliminares, sejam tidas em consideraçao˜ todas as disciplinas envolvidas e incorporadas tecnicas´ de otimizaçao.˜ Com o objetivo de aplicar estes con- ceitos de otimizaçao˜ multidisciplinar, esta´ a ser criada pela Area´ Cient´ıfica de Engenharia Aeroespacial um ferramenta para ser usada na fase de projeto preliminar, o MDOGUI, a qual esta´ a ser desen- volvida no ambitoˆ do enquadramento do projeto NOVEMOR inserido no 7o Programa Quadro da UE. Um modulo´ capaz de modelar com media´ fidelidade um turborreator de duplo fluxo e um turboelice´ foi implementado que, contrariamente ao realizado noutros processos de otimizaçao˜ multidisciplinar, foi desenvolvido desde o in´ıcio para ser totalmente integrado juntamente com os restantes modulos.´ Os modelos do turborreator de duplo fluxo e do turboelice´ implementados inclu´ıram uma analise´ em Condiçoes˜ de Projeto, onde o desempenho do motor e´ estudado para um unico´ Ponto de Projeto, seguida por uma analise´ fora das Condiçoes˜ de Projeto e onde a performance do motor e´ testada para todas as condiçoes˜ de operaçao.˜ Adicionalmente, foi tambem´ implementado um modelo com base em dados historicos´ para o calculo´ do peso e dimensoes˜ do turborreator de duplo fluxo. Para validaçao˜ dos resultados dos modelos, estes foram comparados com resultados dispon´ıveis em literatura e num exemplo de motor e missao˜ fornecido pela Embraer, um dos parceiros do projeto NOVEMOR. Com o objetivo de reduzir o consumo de combust´ıvel de um motor, for executado um processo de otimizaçao˜ com o objetivo de determinar o Ponto de Projeto que define o motor com menor consumo de combust´ıvel ao longo de um dado perfil de missao.Com˜ este processo foram encontrados resultados promissores, uma vez que foi obtida uma reduçao˜ no consumo de combust´ıvel de ate´ 19%, quando comparado o motor otimizado com o motor standard. Palavras-chave: Performance de motor, Turborreator de duplo fluxo, Turbo-helice,´ Otimizaçao˜ multidisciplinar, Minimizaçao˜ do consumo de combust´ıvel, Projeto preliminar de aeronaves. vii viii Abstract The more stringent environmental regulations imposed to air transportation together with the predicted growth of air travelling, demand a great effort in the development of more fuel efficient aircraft. In order to answer to these requirements, the design process for new aircraft is evolving. Nowadays, right from the preliminary studies, all aircraft disciplines are evaluated and are being incorporated in optimization environments. With the objective of applying Multidisciplinary Design Optimization (MDO) techniques, a preliminary design tool, MDOGUI, included in the scope of the EU 7th Framework project NOVEMOR, is being developed by the IST Aerospace Group. To be added to this tool a medium-fidelity propulsion module capable of modelling turbofan and turboprop engines was developed. Unlike to other already developed MDO frameworks, the propulsion module in this case was built from the scratch to be fully integrated with the other modules. The turbofan and turboprop models included an On-Design analysis, where the initial performance of the engine is studied for a single Design Point, followed by an Off-Design analysis where the engine performance is studied along its operating range. In addition, a weight and size models for the turbofan were defined based on historical data. A comparison of results with information found in literature and other engine and mission data provided by a NOVEMOR project partner, EmbraerTM, was done for the model verification. With the ultimate objective of reducing the fuel consumption of the engine, an optimization process was executed in order to determine the engine Design Point that delivers the most fuel efficient engine design across a given flight mission profile. From this process, promising results were obtained, given that reductions of up to 19% on the total fuel burned for a typical regional jet mission were achieved when comparing a standard engine design to a mission optimized engine design. Keywords: Engine performance, Turbofan, Turboprop, Multidisciplinary Design Optimization, Fuel Consumption Minimization, Preliminary Aircraft Design. ix x Contents Acknowledgments...........................................v Resumo................................................. vii Abstract................................................. ix List of Tables.............................................. xiii List of Figures............................................. xvi Nomenclature.............................................. xix Glossary................................................1 1 Introduction 1 1.1 Context and Motivation......................................1 1.2 Multidisciplinary Design Optimization..............................2 1.3 Propulsion module........................................5 1.3.1 Aircraft engines......................................5 1.3.2 Propulsion models’ state-of-the-art...........................7 1.3.3 Objectives and Approach................................ 11 2 Turbofan engine modelling 13 2.1 Parametric model (On-Design)................................. 17 2.2 Performance model (Off-Design)................................ 28 2.3 Weight and size model...................................... 35 3 Model Results and Verification 41 3.1 On-design and Off-design analysis results........................... 41 3.2 Model application for GE CF34-10E and results comparison................. 45 3.3 Application of a modelled engine to a flight mission...................... 48 3.4 On-design and Off-design analysis results for the Turboprop model............. 51 4 Optimization of a turbofan mission’s fuel consumption 55 4.1 Optimization of engine design variables for a Design Point.................. 55 4.2 Optimization of fuel consumption on a given flight mission.................. 58 5 Conclusion 61 5.1 Future Work............................................ 62 xi Bibliography 66 A Engine database 67 xii List of Tables 2.1 Reference stations for High Bypass Ratio Turbofan model.................. 18 2.2 Components of the engine and corresponding stations and subscripts........... 19 2.3 Mass flow rates description, location and identifying subscript................ 21 2.4 Component polytropic efficiencies and total pressure losses [26].............. 22 2.5 Off-Design analysis variables.................................. 29 3.1 Input values for the on-design analyses............................. 42 3.2 Input values for the off-design analysis............................. 43 3.3 Input values for the GE CF34-10E analysis........................... 46 3.4 Weight and Length comparison between modelled and real engine............. 48 3.5 Fuel consumption on Taxi, Take-off and Landing flight phases................ 51 3.6 Input values for the on-design analyses of the turboprop engine............... 51 4.1 5-point mission flight inputs................................... 56 4.2 Results for design variables resulting from an optimization process using Interior Point algorithm.............................................. 57 4.3 Results obtained for various optimization algorithm settings.................. 58 4.4 Results of engine Weight and Block Fuel calculated for each DP engine........... 59 A.1 Turbofan engine Database.................................... 67 A.2 Turbofan engine Database cont. ................................ 68 xiii xiv

Load more