Fast aerodynamic design of a one-stage axial gas turbine in order to produce a 3D geometry ready for optimization Artur Jo˜ao Carvalho Batista Soares de Figueiredo Thesis to obtain the Master of Science Degree in Aerospace Engineering Supervisor Professor Afzal Suleman Examination Committee Chairperson: Professor Fernando Jos´e Parracho Lau Supervisor: Professor Afzal Suleman Member of the Committee: Professor Jo˜ao Manuel Melo de Sousa October 2014 To my Mother, for all the help given at all times i The Wright Brothers created the single greatest cultural force since the invention of writing. The airplane became the first World Wide Web, bringing people, languages, ideas, and values together. Bill Gates iii Acknowledgements The fulfilment of this thesis would have been impossible without the help of many people. Therefore, I must express my thanks: To my supervisor at Von Karman Institute for Fluid Dynamics, Professor Tony Arts, for his patience, wisdom and guidance throughout my six months at VKI; To my supervisor at Instituto Superior T´ecnico of Lisbon, Professor Afzal Suleman, for taking care of thenecessaryarrangementssothatIcouldconductmyMaster’sthesisatVKI(includingarecommendation letter) and for presenting my thesis at IST Lisbon; To Zuyher Alsalihi, with whom I compared the results of the C program hereby developed, and hence helped me find mistakes and make improvements in the code; To Lasse Mu¨ller, for kindly allowing me to use his improved figures for the Craig & Cox correlation; To Professor Filipe Cunha, for sharing his experience at VKI and for one of the recommendation letters that allowed me to apply for this institute; To Professor Fernando Lau, for (more than once) helping me with the documents always necessary for conducting a period of study abroad; To Instituto Superior T´ecnico, for preparing me as an engineering student as I wouldn’t be prepared anywhere else; To Von Karman Institute for Fluid Dynamics, for all the shared knowledge and the inviting and friendly work environment; To Technische Universiteit Delft, for the engineering insights and for my first introduction to Turbo- machinery and engines in general; To my friends, who have, in some way, assisted me in conducting my Master’s Thesis at VKI, Alberto Serrano, Bruno Dias, Charline Fouchier, David Cuadrado, Joa˜o Aguiar, Jos´e Veiga, Mar´ılia Avelar, Pedro Santos, Rui Jaulino, Tiago Barros and Valeria Andreoli; To my Mother, Cˆandida Perp´etua Carvalho, for all the help given at all times. Brussels, October 2014 v Abstract The turbine plays a vital role in major industries worldwide, namely in electricity generation and the aerospace industry. The preliminary design phase of a turbine (one of most important phases of the overall design, since it sets the tone for all subsequent design stages and results) is nowadays often carried out by hand. However, in any industry, reducing costs and increasing efficiency are everyday goals. The need for an automatic, fast and reliable way to perform a preliminary design of an axial turbine in order to produce a 3D geometry ready for optimization brings us to the purpose of this thesis. The necessary tools for such a preliminary design are nowadays accepted knowledge for any turbine designer. Thepurposeofthisworkistousethisknowledgeforthecreationofamethodology, codedintoa C program, capable of delivering a feasible and realistic turbine preliminary design ready for optimization, starting only with data from the engine this turbine belongs to. Typical thermodynamic analysis of an engine (turboshaft), followed by the application of mean line analysis and radial equilibrium theory (ISRE and NISRE) and subsequent airfoil selection compose the main tools in this design. Loss calculation is included with Soderberg’s correlation in the 1D design (MLA), and with Craig & Cox’s method in the 2D design (RET). The objective of this thesis was therefore attained, with the development of a methodology able to deliver a full 2D design of a turbine and consequently a 3D geometry. Keywords: turbine design, preliminary, MLA, RET, airfoil. vii