支板布局对三维侧压式进气道特性的影响

Effect of strut configuration on 3-D sidewall compression scramjet inlet

关键词:  超音速进气道  支板  前掠  后掠  混合掠

Key words:  Supersonic inlet  Strut  Aft sweep  Forward sweep  Aft-forward sweep

摘要:

对采用前掠、后掠及混合掠支板布局的三维侧压式超燃发动机进气道(工作马赫数4~6)开展了数值计算,详细比较了不同支板布局的流场波系、边界层发展以及总体性能特征,主要结论有:(1)后掠支板进气道的起动马赫数范围较宽,但附加溢流大,需前移唇口保证流量系数,结果上顶板反射激波加强,总压损失和流场畸变较大;(2)前掠支板进气道能保证较高的流量系数及总压恢复系数,但低马赫数起动困难;(3)混掠支板进气道综合了前掠与后掠布局的优点,能够保证较宽马赫数范围内的工作和较优的进气道性能,但需优化。

Abstract:

Three kinds of sidewall compression scramjet inlets with aft,forward and Aft-Forward strut-sweeping configuration were numerically investigated.These scramjet inlets were operated in Mach number 4~6.The flow fields,shock wave structure,turbulence boundary layer development and overall performance characteristics of different scramjet inlet configuration were analyzed.It is concluded that:(1) Aft strut-sweeping inlet can possess wide operation Mach number range with small inner contraction ratio and the large spillage.Upstream displacement of inlet lip can reduce the spillage rate but lead to stronger reflecting shock on the top wall,which increases total pressure loss and flow distortion at the inlet exit;(2) Forward strut-sweeping inlet can ensure large mass flow rate coefficient and total pressure recovering factor,but is difficult to start at low mach number;(3) the aft-forward strut-sweeping inlet,inheriting both advantages of Aft and Forward strut-sweeping inlets,can have a more favorable performance than solely Aft or Forward strut-sweeping inlets,which can be further enhanced by adjustments of forward/aft strut position,cowl shape and compressing angle as well as shock wave structure.