超声速/高超声速风洞试验段结构形式对流场性能的影响研究

Investigation of the performance of flow field in supersonic/hypersonic wind tunnel with different test section geometry configurations

通过求解轴对称N-S方程,对Φ1m高超声速风洞马赫数3和6状态下的流场进行了模拟,计算结果与试验数据基本一致,验证了所用数值方法的可信性。在此基础上,对比研究了马赫数3和6状态下采用闭口等直圆截面和开口自由射流两种试验段结构形式的超声速/高超声速风洞在起动条件下的稳态流场性能。结果表明:采用闭口等直圆截面试验段和开口自由射流试验段的流场均匀区内速度场性能指标均满足相关标准要求;马赫数3喷管采用闭口试验段时,沿风洞轴向-300mm^900mm截面范围内的流场均匀区直径均保持在Φ882mm以上,均匀区面积较开口试验段增加了约31.57%;马赫数6喷管采用闭口试验段时,均匀区面积比开口试验段仅增加了约8.24%,流场品质略为提高。超声速条件下,闭口试验段的流场均匀区增加明显;但在高超声速条件下,闭口试验段的流场均匀区增加比较有限。

The steady flow fields of the Ф1 m hypersonic wind tunnel are simulated under Mach number 3 and 6 by solving axisymmetric N-S equations.The comparison between the nu-merical simulation and experimental data validates that this numerical method is feasible.And then the flowfields of wind tunnels with closed straight round and unclosed free-jet test sections under these Mach numbers are simulated respectively.The results of uniformity test core of closed straight round and unclosed free-jet test sections meet the requirement of relevant stand-ards.The results show that the minimum diameter of the uniformity test core in Mach 3 nozzle with closed test section reaches Φ882mm at the axial coordinate from-300mm to 900mm.The test core increases by about 31.57% compared with free-jet test section,which significantly im-proves the test capacity of wind tunnel.For Mach 6 nozzle with closed test section,the uniformi-ty test core only increases by about 8.24% compared with unclosed test section,which makes lit-tle improvement on the flowfield performance.The uniformity test core of supersonic wind tun-nel with closed test section enlarges observably,but it is little larger in hypersonic wind tunnel with closed test section than that with unclosed free-jet test section.