脉冲爆震发动机自吸气实现方式

Methods to self-aspirating air breathing pulse detonation engine

关键词:  航空、航天推进系统  爆震波  脉冲爆震发动机  自吸气+  数值仿真

Key words:  Aerospace propulsion system  Detonation wave  Pulse detonation engine  Self-aspirate+  Numerical simulation

摘要:

根据脉冲爆震发动机工作循环过程中的压力变化特点,对脉冲爆震发动机自吸气的实现方式进行了探索研究,设计了几种不同的结构型式以改善尾部吸气质量,并进行了数值模拟。结果显示:单一等截面直爆震管虽然可以在爆震后管内负压作用下从尾部自吸气,但是吸入的基本全是尾气,无法用于再次爆震起爆;进、排气口分开有利于改善自吸气质量,进气口离排气口越远,尾气影响越小,吸气质量越好;进、排气口间最好有一定压差,否则会出现两端同时进气,形成吸气震荡,并在爆震管中部夹有燃气无法排出;利用设计的气动阀可以实现从爆震管前端自吸气,吸气结束后整个爆震管内充满新鲜空气,可以用于再次爆震起爆。

Abstract:

Four different types of structure to probe into the self-aspirating character of the air breathing pulse detonation engine according to the pressure variation in a cycle were studied numerically.The exploratory research shows that constant section straight detonation tube can self-aspirate from the open end at the low pressure in the tube after the purge process.However,the gas inhaled was almost totally exhaust gas which cannot be used for the next cycle.The separation of intake port and exhaust port can improve the quality of the inhaled gas.The far the intake port departs from the exhaust port the less influence the exhaust gas has and the better the self-aspiration quality will be.Pressure difference between the intake port and the exhaust port should exist.Otherwise,gas will be inhaled in from the two ports simultaneously forming gas oscillation in the tube and blocking up some exhaust-gas in the middle of the tube.With the help of designed aerodynamic valve the detonation tube can self-aspirate from the front end at the end of the purging process filling the tube with fresh air,which can be used for the next cycle.