Busemann进气道起动问题初步研究

Preliminary investigation on Busemann inlet starting characteristics

关键词:  超音速冲压喷机发动机  Busemann进气道+  起动  数值仿真

Key words:  Supersonic combustion ramjet engine  Busemann inlet~+  Starting  Numerical simulation

摘要:

为了研究流线跟踪Busem ann进气道低马赫数下的起动性能,对设计马赫数Ma1=7,收缩比CR=6的3°截短前后的流线跟踪进气道在Ma=4来流条件下的起动性能进行了无粘数值分析,研究发现:与基准进气道相比,虽然流线跟踪进气道的起动性能显著提高,但它仍不能实现自起动的目标,通过部分切除唇口板的方法将唇口后移,使进气道溢流面积增大,内收缩比减小,并通过逐渐增大切除量的方式,发现3°截短流线跟踪进气道能够自起动的最大参考内收缩比在1.255~1.27之间,并发现在保证该进气道Ma=4自起动的条件下,它在设计状态仍然具有较高的无粘性能。

Abstract:

Inviscid flow lations were performed to study the starting characteristics of square streamtraced inlets at Ma=4 and they are designed for Mach 7 flight and has a same contraction ratio of 6.The results show that streamtraced inlet has a better starting performance than full Busemann inlet,but this inlet is not self-starting yet.In order to realize that 3° truncated streamtraced inlet can be started at take-over Mach number,cut-back of the cowl allow more flow spillage and a reduced internal contraction ratio,it is observed that its maximum reference internal contraction ratio which can be started is between 1.255 and 1.27.With the inlet self-starting at Ma=4,it has still high efficiency at design point.