Boundary conditions for unsteady supersonic inlet analyses
Boundary conditions for unsteady supersonic inlet analyses
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DOI：
10.2514/3.12120
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发表时间：
1994-06
期刊：
影响因子：
2.5
通讯作者：
D. Mayer;G. Paynter
中科院分区：
文献类型：
--
作者：
D. Mayer;G. Paynter
为了提高非定常超声速进气道计算的精度，提出了新的引气和压气机端面边界条件。新的引气边界条件将引气孔流量系数的变化与局部流动条件的变化联系起来;当激波在引气带上向前移动以响应进口气流扰动时，局部引气流量可增加一倍以上。进气道的稳定裕度与喉部引气结构密切相关，因为引气流量的局部快速增加对正激波的运动有很大的影响。新的压气机面边界条件通过将压气机面修正质量流量或马赫数指定为常数或滞止条件的线性函数来说明压气机面处非定常流动条件的变化。与传统的固定静压或质量流量条件相比，这种新的边界条件更真实地反映了进口气流扰动对压气机端面气流的影响。本文报道了进口气流对20 °和90 °喉道放气孔角压气机端面气流扰动的动态响应的欧拉计算。这些结果表明，采用90 °引气孔可以获得进气道的额外稳定裕度，因为当激波在引气带上向前移动时，90 °孔的引气流量的增加比20 °孔大得多。
New bleed and compressor face boundary conditions have been developed to improve the accuracy of unsteady supersonic inlet calculations. The new bleed boundary condition relates changes in the bleed hole discharge coefficient to changes in the local flow conditions; the local bleed flow rate can more than double as a shock moves forward over a bleed band in response to inlet flow disturbances. The stability margin of the inlet is strongly dependent on the throat bleed configuration since the locally rapid increase in bleed flow has a strong effect on the motion of the normal shock. The new compressor face boundary condition accounts for changes in the unsteady flow conditions at the compressor face by specifying the compressor face corrected mass flow or Mach number either as a constant or as a linear function of the stagnation conditions. The effects of inlet flow disturbances on the flow at the compressor face are represented more realistically with this new boundary condition than with traditional fixed static pressure or mass flow conditions. Euler calculations of the dynamic response of an inlet flow to a flow disturbance at the compressor face with 20- and 90-deg throat bleed hole angles are reported. These results indicate that an extra margin of stability for the inlet is obtained with 90-deg bleed holes because the increase in bleed flow rate as the shock moves forward over a bleed band is much larger for 90-deg holes than for 20-deg holes.