风洞分流锥及孔板整流的数值模拟研究

采用数值模拟技术研究了2m×2m超声速风洞设计引导试验大开角扩散段配置一个中心倒锥和两层球冠状孔板的内流场,中心倒锥和两层球状孔板的不同组合共有五套。孔板有几百至上千个开孔,是模拟的难点,发展了一种孔板流动CFD边界条件模型。另一个难点在于风洞管道内流入口和出口边界条件的准确处理。计算表明,分流锥可将流动有效抑制在大开角洞壁附近,防止洞壁附近的扩张分离,但在分流锥底部将产生大尺度的分离涡环结构,经过孔板的整流后,总压有较大损失,但流线趋于平直,可达到预期效果。

Numerical study of the flow adjustment by the combination of a pointed cone and screens in the wind tunnel

The inner flowfields of the big open diffuser composed of a pointed cone for separate flow and two screens in five combinations are numerically studied, which were conducted for the 2m×2m supersonic wind tunnel design test analysis. There are hundreds of or even thousands of small holes on the screen, which makes the flow across the screen very difficult to be computed directly by CFD method. To overcome this problem, a boundary model for the flow across screen was built up. Another key technique in the CFD process is the accurate treatment of the inflow and outflow boundary. The numerical results show that the pointed cone can control the separation effectively near the wind tunnel wall, but strong vortex is generated behind the cone base, then the flow get across the screen with big total pressure loss, but the streamlines be-come straight. The effect was as expected.