凹腔前后缘圆弧对流场干扰的数值研究

基于两方程k-ωSST模型,对不同半径前后缘圆弧凹腔构型的超声速流场进行了二维仿真,获得了相应的流场特征参数。结果表明,与直角前后缘相比,采用圆弧构型时凹腔后壁的激波得到增强;随着圆弧半径的增加,凹腔内部的速度有所增大,而温度、涡量则呈递减趋势,从稳焰、助燃的角度看,后壁上端压力增大可以促进质量交换,同时降低回流区温度。综合考虑凹腔的稳焰和助燃作用,提出了一个适当的圆弧半径范围。

Numerical study on effect of arc leading edge and trailing edge of cavity on flow field

The two-dimensional simulation for the supersonic flow field of concave-cavity architectures with different radius arc leading and trailing edges was carried out based on κ-ω SST model. The corresponding flow field feature parameters were obtained. The simulation results show that, compared with the right angle leading and trailing edges, the shock wave was strengthened near the trailing edges when using the arc edges. By contrast, cavities with different arc radius were considered when the velocity, temperature and vorticity were calculated. It demonstrates that, with the increase of arc radius, the velocity inside the cavity increases, and temperature and vorticity magnitudes appears a decline trend. As viewed from flame stabilization and combustion-supporting, the pressure increase at the upper end of back wall can promote the mass exchange and at the same time, can lower the temperature in recirculation zone. A proper limit of the arc radius is proposed in overall consideration of flame stabilization and combustion-supporting effect of concave-cavity.