关键词: 超声速民机, 跨速域, 排气系统, 推力特性, 风洞试验

Abstract:

There is mutual interference between engine jet and airframe flow， but there is not enough research on thrust characteristic of exhaust system under the condition of airframe flow. The reason is that the traditional jet test platform only simulates the nozzle pressure ratio condition corresponding to the working condition of the exhaust system， but it can’t simulate the flow condition in front of the aircraft. The flight velocity domain of supersonic aircraft is wide， covering many speed domains such as low speed， subsonic speed， transonic speed and supersonic speed， which make the interaction between engine jet and airframe flow more complex and changeable. This paper presents a wind tunnel test method for the thrust characteristics of supersonic ejector exhaust system under the constraints of supersonic aircraft airframe， and obtains the variation law of the thrust characteristics of the ejector exhaust system under the conditions of multi-flight velocity domain circumfluence of supersonic aircraft. The experimental results show that there is a great difference between the design state and the non-design state thrust characteristics of the supersonic ejector exhaust system in different speed ranges. The thrust coefficient of the design state can reach above 0.98 and the minimum thrust coefficient of the non-design state can be reduced to around 0.79. The experimental results can provide an important basis for the design of the supersonic ejector exhaust system and the performance tradeoff design of the non-design point. Based on the results of numerical simulation， the characteristics of the flow field and the relationship between the design state and the non-design state of the supersonic ejector exhaust system and the thrust characteristics are analyzed.

Key words: supersonic civil aircraft, cross-speed domain, exhaust system, thrust characteristics, wind tunnel test