Study on Inlet and Engine Integrated Model with Normal Shock Position Feedback

Haoying Chen,Zhihua Xi,Qiangang Zheng,Haibo Zhang

doi:10.1155/2020/5313941

Abstract

In order to consider the inlet and engine integrated model of supersonic airliner, the dynamic identification and control of inlet normal shock are studied. The research is based on the bleed air flow rate under supersonic conditions. With the two-dimensional CFD model of supersonic inlet, the dynamic and static effects of the bleeding flow rate on the normal shock position were investigated. The transfer function was identified, and simultaneously the paper carried out a comprehensive study of inlet and engine integrated model, which is established based on the inlet shock position model and engine component level model. The relationship between normal shock position and total pressure recovery coefficient has been taken into consideration in this model. Based on the inlet and engine integrated model, the closed-loop control simulation of normal shock position is carried out. The results show that the model could resist the disturbance of the inlet flow and keep the inlet and engine matching operation point stable near the optimal value.

Highlights

The aircraft may encounter various disturbances in flight, such as the atmospheric turbulence, the shock waves of passing through another aircraft, and the pulsation of engine airflow, which would affect the inlet operation
In order to adapt the disturbance, the inlet may increase the bleed flow leading to the bleed drag, which is shown in Figure 1. (Cbp is the coefficient of bleed drag, Ableed is the bleed area, and Ac is the inlet capture area.) even if the shock wave remains at a position of high-pressure recovery coefficient, it may still cause a net loss of the propulsion system [3, 4]
When the system does not include active disturbance rejection control (ADRC) controller, the disturbance of normal shock wave position is transmitted directly to the engine model that results in the huge change of total pressure recovery coefficient σ and thrust F

Summary

Introduction

The aircraft may encounter various disturbances in flight, such as the atmospheric turbulence, the shock waves of passing through another aircraft, and the pulsation of engine airflow, which would affect the inlet operation. When the aircraft is in high Mach number cruise, the upstream and downstream flow fields of the inlet are prone to fluctuate due to the drop of shock wave, the change of atmospheric environment, or the launch of weapon It causes the change of inlet normal shock wave position and affects the stability of inlet or even causes the engine surge [12,13,14]. The research is focused on the integrated control of inlet and engine for supersonic airliner based on the control technology of normal shock wave position This technology improves the anti-interference performance of the inlet and makes the inlet and engine operate at a better matching point. The inlet and engine integrated control model are established to reduce the influence of atmospheric disturbance to the propulsion system performance

Inlet and Engine Integrated Model

Simulation of Integrated Model

Findings

Conclusions