An Analytic Study on Mathematical Modeling of Area-Pressure Relation of Jet Engine Convergent-Divergent Nozzles

Hom-Yu Wu ； Kuo-Chien Liao ； Hung-Ta Wen

《Journal of Aeronautics, Astronautics and Aviation》 55卷2S期 Vol.55 No.2S AASRC 2022 Special Issue (2023/06) Pp. 277-287

https://doi.org/10.6125/JoAAA.202306_55(2S).08

摘要

The exhaust nozzles are important component for aero engine to generate thrust, and convergent nozzle and convergent-divergent nozzle (C-D nozzle) are the two main types of exhaust nozzles. The mathematical equations required for the performance analysis of the flow field of converging nozzles have been fully provided in textbooks related to turbine engines, but for C-D nozzles, only the area-Mach number relation is provided, which is not enough for nozzle designers. The purpose of this study is to derive the area-pressure relation of the C-D nozzle, so as to provide a convenient calculation rule for the performance analysis or design of the C-D nozzle. In the verification part, the calculation result of the area-pressure relation is verified with the actual experimental report, and the results show that it has a fairly good accuracy. In addition, this area-pressure relation can further predict the location of shock wave when the nozzle flow is overexpansion and its influences on nozzle flow performance, as well as the location of expansion wave and its influences on nozzle flow performance when the nozzle flow is under-expansion.

關鍵字

Jet engine ； Convergent-divergent nozzle ； Area-pressure relation

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