Influence of secondary flow on aero-engine performance

Abstract

In the actual design of turbofan engine with a high thrust-weight ratio, its secondary flow comes from the engine compression parts (fan or high pressure compressor), no matter the Fluidic Thrust Vector (FTV) nozzle is based on Shock Vectoring Controlling (SVC) or Throat Shift (TS). When the turbofan engine works in the state of thrust vector, regardless of the air bleeding from fan or high pressure compressor, the secondary flow have an impact on the components matching and engine performance. Therefore, the study of FTV technology in structurally fixed nozzle cannot just focus on a single nozzle, in the meantime, nozzle should be installed in the actual environment considering the synthesis of flow loss caused by bleed air (for example, bleed air from the compressor) and mixing of the main flow and secondary flow in the nozzle expansion section as well as effect on engine cycle and performance caused by the shockwave loss. Based on this consideration, this article proposes a component-based matching technique, which is applied via numerical simulation in the real environment. The main purpose of this article is research on the effect of FTV on the engine thermodynamic cycle and performance (thrust, fuel consumption and other parameters), considering the processes both air bleeds from fan/high pressure compressor, and it injects into the nozzle expansion section through the holes / slot.