不起动流场对超声速/高超声速进气道自起动性能的影响

对7个典型速域的二维超声速/高超声速进气道加速自起动过程进行了准定常数值仿真,分析了真实临界不起动流场对进气道自起动性能的影响,研究发现:存在一种介于超声速和高超声速临界不起动模式之间的过渡临界不起动模式。当真实不起动流场处于超声速临界不起动模式时,自起动马赫数略大于无黏设计自起动马赫数;处于过渡临界不起动模式时自起动马赫数小于无黏设计自起动马赫数;而该研究中处于高超声速临界不起动模式的进气道,自起动马赫数明显大于无黏设计自起动马赫数。高超声速临界不起动模式下的喉道截面特征气流参数显著偏离无黏临界不起动流场,所以Kantrowitz理论以及基于该理论发展而来的系列方法不适用于预测高超声速进气道自起动性能。

Influence of unstart flowfields on self-starting ability of supersonic/hypersonic inlets

The accelerating self-starting process of seven typical two-dimensional supersonic/hypersonic inlets with different speed ranges was studied using quasi-steady numerical simulation. The influence of unstart flow-fields on self-starting ability was analyzed and a kind of transitional critical unstart mode between supersonic critical unstart mode and hypersonic critical unstart mode was discovered. When the viscous critical unstart flow-field was in the supersonic critical unstart mode, the viscous self-starting Mach number was greater than the inviscid designed self-starting Mach number slightly. When the viscous critical unstart flow-field was in the transitional critical unstart mode, the viscous self-starting Mach number was smaller than the inviscid designed self-starting Mach number. When the viscous critical unstart flow-field is in the hypersonic critical unstart mode, the viscous self-starting Mach number is significantly greater than the inviscid designed self-starting Mach number. In the hypersonic critical unstart mode, the key parameters in the viscous unstart flow-field deviated far from those in the inviscid unstart flow-field, indicating that Kantrowitz theory and other theories based on Kantrowitz theory are not capable of predicting the self-starting ability of hypersonic inlets.