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低空高速突防红外制导系统的球形整流罩通常工作在湍流换热状态,文中以零攻角球锥体为基础,结合结构网格、来流物性参数、驻点及湍流球面换热工程公式,探索出一种将SST模型应用于整流罩湍流换热数值计算的工程方法。首先根据Billig公式,利用分块结构网格在流场中构造脱体激波,以降低数值耗散,然后通过壁面网格高度调整,分析计算结果对近壁网格的敏感度。在此基础上,分析SST模型参数对计算结果的影响,其中Bradshaw数仅对峰值热流影响较大。在驻点层流区域,通过来流的等效热导率修正使SST模型热流计算结果与Klein公式相符。在球面湍流区域,利用高速球体湍流换热工程公式对Bradshaw数进行修正,使SST模型热流计算结果与该工程算法相符。修正后的SST模型的计算结果具有工程精度,可用于整流罩抗热冲击、气动光学效应、图像非均匀校正以及红外、激光末制导的弹道设计等分析研究,具有重要的工程意义。
The spherical fairing of low altitude and high altitude sudden stop infrared guidance system usually works in the condition of turbulent heat transfer. Based on the zero-angle cone, combined with the structural grid, the flow parameters, stagnation point and turbulent spherical heat transfer engineering formula are explored An engineering method of applying SST model to numerical calculation of turbulent heat exchange in fairing is presented. According to the formula of Billig, the shunt structure grid is used to construct a shock wave in the flow field to reduce the numerical dissipation, and then the wall grid height adjustment is adopted to analyze the sensitivity of the calculation result to the near-wall grid. Based on this, the influence of SST model parameters on the calculation results is analyzed. Among them, the Bradshaw number only affects the peak heat flow significantly. In stagnant laminar flow region, the heat flow calculation results of SST model accord with Klein formula through the correction of equivalent thermal conductivity of incoming flow. In the spherical turbulence region, the Bradshaw number is corrected by using the high-speed turbulent heat transfer equation of the sphere, and the heat flow calculation result of the SST model is in accordance with the engineering algorithm. The corrected SST model has the engineering precision and can be used in the analysis and study of the thermal shock resistance of the fairing, the aerodynamic optical effect, the non-uniform image correction and the ballistic design of the infrared and laser end guidance, which has important engineering significance.