马赫5一级定几何二元混压式进气道反压特性试验研究

Experimental Investigation on Back-Pressure Characteristic of Ma 5 Fix-Geometry Two-dimensional Inlet with Mixed-Compression

对一种设计马赫数为5一级的定几何二元混压式亚燃冲压发动机进气道进行了风洞试验研究,得到了该进气道的反压特性,结果表明:设计状态时,随节流锥堵塞度的增加,进气道出口反压比不断增加,马赫数逐渐下降,总压恢复系数先下降后上升,通道内气流脉动的功率谱密度无明显峰值;节流锥堵塞比为72%时,进气道发生喘振,喘振基频约为48Hz;随节流锥堵塞比的降低,进气道喘振基频逐渐降低,进气道结束喘振后结尾激波先到达进气道进口处,然后稳定在进气道内收缩段内,随着节流锥堵塞比的进一步降低,结尾激波逐渐进入进气道扩张段。

Experiments of a Ma 5 fix-geometry two-dimensional ramjet inlet with mixed-compression are conducted in a hypersonic wind tunnel.The results show that：under cruising condition,when the throttling ratio increases,at the exit of the inlet,the back pressure ratio rises,the Mach number decreases and the total pressure recovery coefficient declines firstly and rises then.The power spectrum of the dynamic pressure signals in the duct generally has no obvious peak value.When the throttling ratio is equal to 72%,buzz occurs in the inlet.The base frequency of the buzz is about equal to 48 Hz.As the throttling ratio decreases,the base frequency of the buzz declines and the terminal shock reaches the intake when the buzz ends.With a further decrease of the throttling ratio,the terminal shock firstly locates at the internal compression section and then enters the divergent section.