Abstract
The intention of this paper is to research the inlet flow distortion influence on overall performance of turboshaft engine and put forward a method called Distortion Factor Item (DFI) to improve the fuel supply plan for surge-preventing acceleration when turboshaft engine suddenly encounters inlet flow distortion. Based on the parallel compressor theory, steady-state and transition-state numerical simulation model of turboshaft engine with sub-compressor model were established for researching the influence of inlet flow distortion on turboshaft engine. This paper made a detailed analysis on the compressor operation from the aspects of performance and stability, and then analyzed the overall performance and dynamic response of the whole engine under inlet flow distortion. Improved fuel supply plan with DFI method was applied to control the acceleration process adaptively when encountering different inlet flow distortion. Several simulation examples about extreme natural environments were calculated to testify DFI method’s environmental applicability. The result shows that the inlet flow distortion reduces the air inflow and decreases the surge margin of compressor, and increase the engine exhaust loss. Encountering inlet flow distortion has many adverse influences such as sudden rotor acceleration, turbine inlet temperature rise and power output reduction. By using improved fuel supply plan with DFI, turboshaft engine above-idle acceleration can avoid surge effectively under inlet flow distortion with environmental applicability.
Highlights
Helicopters often encounter inlet flow distortion in flight
2) Section two analyzed the influences of inlet flow distortion on the overall performance from the perspective of the whole turboshaft engine.. 3) Section three presented the Distortion Factor Item (DFI) method to improve fuel supply plan for surge-preventing acceleration and testified its environmental applicability
Acceleration was simulated with improved fuel supply plan under the condition of inlet flow distortion
Summary
Helicopters often encounter inlet flow distortion in flight. Inlet flow distortion can be caused by many sources such as crosswind-induced inlet separation, armament firing, and shock-boundary layer interaction in a supersonic inlet. High Stability Engine Control (HISTEC) program [6] researched by NASA was to design, develop, and flight demonstrate an advanced, high-stability, integrated engine control system that uses measurement-based, real-time estimation of distortion to enhance engine stability. HISTEC installed on the F-15 Advanced Control Technology for Integrated Vehicles aircraft at NASA Dryden and the HISTEC technologies were successfully flight demonstrated It indicated that inlet flow distortion parameters can be accurately estimated real-time in the future. It is the simplest form of circumferential distortion, including both steady-state and dynamic-state. This paper is mainly divided into three major sections: 1) Section one introduced the modeling of turboshaft engine and sub-compressor. 2) Section two analyzed the influences of inlet flow distortion on the overall performance from the perspective of the whole turboshaft engine.. 3) Section three presented the DFI method to improve fuel supply plan for surge-preventing acceleration and testified its environmental applicability
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
