不同迎角下逆向喷流减阻降热特性研究

Study on Drag and Heat Reduction Performance of Opposing Jet at Different Angle of Attack

文章采用基于SST k-ω湍流模型的N-S(Navier-Stokes)方程数值模拟方法,探究不同来流迎角下,逆向喷流与钝头体同轴及不同轴时,同自由来流相互作用产生的干扰流场对减阻降热效果的影响。结果表明:与无喷流情况相比,同轴逆向喷流能有效减小钝头体的阻力系数,迎角为2°时阻力系数可减小32.53%;迎角较小时,同轴逆向喷流可有效减小壁面斯坦顿数,迎角较大时,迎风面壁面斯坦顿数较大,背风面壁面斯坦顿数大幅减小;逆向喷流与钝头体轴向夹角的变化对流场及减阻降热效果产生影响,喷流与轴线夹角增大,迎风面壁面压强逐渐减小,存在使壁面斯坦顿数峰值取得最优解的喷流角度;较同轴逆向喷流,来流迎角为5°时,壁面斯坦顿数峰值可减小9.02%,来流迎角为8°时,减阻效果最高可提升1.92%。

In this paper,the numerical simulation method of N-S(Navier-Stokes)equation based on SST k-ωturbulence model is used to explore the influence of the interference flow field generated by the interaction between the coaxial or non-coaxial opposing jet and the blunt body with the free stream under different angle of attack on the drag and heat reduction effect.The results show that compared with the no-jet condition,the coaxial opposing jet can effectively reduce the drag coefficient of the blunt body,and the drag coefficient can be reduced by 32.53%when the angle of attack is 2°.When the angle of attack is small,the coaxial opposing jet can effectively reduce the wall Stanton number.And when the angle of attack is large,the wall Stanton number on the windward side becomes large and that on the leeward side is greatly reduced.The change of the axial angle between the opposing jet and the blunt body affects the flow field and the drag and heat reduction effect.As the angle between the jet and the axis increases,the wall pressure on the windward side gradually decreases,and there is a jet angle that can make the peak value of the wall Stanton number reach the optimal solution.Compared with the coaxial opposing jet,when the angle of attack is 5°,the peak value of the wall Stanton number can be reduced by 9.02%,and when the angle of attack is 8°,the drag reduction effect can be increased by up to 1.92%.