Performance and Model Calibration of High-Pressure Compressors
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Performance and model calibration of high-pressure compressors Antoine Brissaud Master of Science Thesis KTH School of Industrial Engineering and Management Energy Technology EGI-TRITA-ITM-EX 2018:22 Division of Heat and Power Technology SE-100 44 STOCKHOLM Master of Science Thesis EGI TRITA-ITM-EX 2018:22 Performance and model calibration of high- pressure compressors Antoine Brissaud Approved Examiner Supervisor 2018/03/02 Paul Petrie-Repar Nenad Glodic Commissioner Contact person Abstract To fully determine the performances of high-pressure compressors (HPC), modeling and partial tests can be performed to characterize its different operating conditions. Nevertheless, there are still noticeable errors between the results of these models and the tests: deformations and differences can appear, and notably because of a modeling defect or the assumptions made during the analysis (measurement corrections for example). To model the closest to the tests, it is therefore necessary to include all the different elements impacting the performances of the compressor performance map to model the operating points correctly. The purpose of the thesis is to take in charge a new software that predicts the performances of high-pressure compressors, built in Python where a compressor can be decomposed in elementary axial and/or centrifugal compressors using their respective compressor performance map. By a stacking technique it is possible to characterize the operating point of the main compressor by knowing the inlet and the outlet conditions, and to include several deformation models such as Reynolds number effects, Variable Stator Vanes (VSV) effects, or tip clearance effects on the performances of the compressor. A calibration function also allows the development of new versions of the previous deformations models and it quantifies the unknowns and uncertainties between computed and tested results. Several working points at off-design conditions were computed with specific operating conditions such as the opening of a handling bleed valve. Deformations models of this specific condition was built to mitigate the uncertainties between computed and tested results and include the phenomenon to the modeling. Several deformations models were also compared for efficiency purposes. -2- Sammanfattning För att fullt ut kunna bestämma prestanda hos högtryckskompressorer (HPC) kan modellering och delprov utföras för att karakterisera kompressorns olika driftsförhållanden. Det finns emellertid fortfarande märkbara skillnader mellan resultaten av dessa modeller och testerna: deformationer och skillnader kan uppstå på grund av en modelleringsdefekt eller antaganden som har gjorts under analysen (t.ex. mätkorrigeringar). För att närma modellen till prov är det därför nödvändigt att inkludera alla de olika elementen som påverkar kompressorns prestanda för att korrekt modellera de olika arbetspunkterna i en kompressor mapp. Syftet med avhandlingen är att implementera en ny Python-baserad programvara som förutspår prestationerna hos högtryckskompressorer, där en kompressor kan brytas ner i elementära axiella och / eller centrifugalkompressorer med tillhörande kompressor prestandamappar. Med en staplingsteknik är det möjligt att karakterisera huvudkompressorns driftspunkt genom att känna till förhållanden vid inloppet och utloppet av huvudkompressorn. Modellen inkluderar olika effekter som Reynolds-tal effekter, ”Variable Stator Vanes”- effekter (VSV) eller påverkan av toppspel. En kalibreringsfunktion tillåter också utveckling av nya versioner av tidigare modeller och kvantifierar osäkerheter och skillnader mellan resultat från simuleringar och de från prövningar. Flera arbetspunkter vid off-design-förhållanden simulerades med specifika driftsförhållanden, såsom öppnandet av avtappningsventiler (”bleed air valves”) och deformationsmodeller för dessa specifika tillstånd togs fram för att minska osäkerheten hos simuleringsresultat. -3- Acknowledgements I would like to use this opportunity to express my gratitude to all the people who helped me throughout my master thesis within Safran Aircraft Engines. I express my deepest thanks to Antonin Meyniel and Stephen Reiser who supervised my work, guided me on the correct path during these six months, and shared their expertise and knowledge on a daily basis. Thanks also to their confidence, I was able to fulfill my missions completely. I had the excellent opportunity to complete my knowledge of companies’ organization from the inside, in one of the world leading aircraft engines manufacturers. I would like to thank Jean-Paul Thibault who supervised my work from my French Engineering School Grenoble INP – Ense3 and Nenad Glodic who accepted to be my supervisor for KTH. I would like to express all my regards and blessings to all of those who supported me in any respect during my thesis, and all the members of the Aero-Mechanical Integration Veins and Blades unit for their welcome. -4- Contents Abstract .......................................................................................................................................................................... 2 Acknowledgements....................................................................................................................................................... 4 Table of figures ............................................................................................................................................................. 7 List of symbols and acronyms .................................................................................................................................... 8 Introduction ................................................................................................................................................................. 10 Group and company presentation .................................................................................................................. 11 Safran group................................................................................................................................................... 11 1.1.1 Aviation and space ................................................................................................................................... 11 1.1.2 Defense ...................................................................................................................................................... 11 Safran Aircraft Engines ................................................................................................................................ 11 1.2.1 Divisions .................................................................................................................................................... 12 1.2.2 Integration of the thesis within the company...................................................................................... 13 Context ................................................................................................................................................................ 13 General operation of a turbojet .................................................................................................................. 13 Study compressor.......................................................................................................................................... 14 2.2.1 Basic principle .......................................................................................................................................... 14 2.2.2 Axial-centrifugal compressor ................................................................................................................. 14 2.2.3 Surge........................................................................................................................................................... 15 2.2.4 Sonic blockage and transonic flows ...................................................................................................... 15 2.2.5 Compressor performance map .............................................................................................................. 15 Deformations of the compressor performance map .............................................................................. 16 2.3.1 Reynolds effect ......................................................................................................................................... 16 2.3.2 Tip leakages effect ................................................................................................................................... 20 2.3.3 Handling bleed valve effect (HBV) ....................................................................................................... 23 The compressor stacking software ................................................................................................................. 23 Introduction to the software ....................................................................................................................... 23 Calibration function ...................................................................................................................................... 24 Stacking function .......................................................................................................................................... 25 Deformation models ...................................................................................................................................