合成双射流控制翼型分离流动的数值研究

合成双射流激励器是合成射流技术发展的最新成果,所形成的射流具有更高能量、流动更稳定的特点。采用数值模拟的方法,对比研究了合成射流与合成双射流对翼型分离流动的改善效果。结果表明:合成射流可以将翼型失速攻角提高2°、最大升力系数增加18%,合成双射流可以将翼型失速攻角提高4°、最大升力系数增加35%,证明了合成双射流具有更好的分离流动控制效果。另外着重分析了合成双射流工作频率和动量系数对控制效果的影响,发现当激励器工作频率为流场特征频率的1和2倍时,对翼型气动特性的改善效果最好,同时控制效果会随动量系数的增加而增大。

Numerical simulation of separated flow control on an airfoil using dual synthetic jets

As the last word of the synthetic jet technology,dual synthetic jets have the characteristics of more energetic and more stable.Numerical computations are performed to study the different effect of single synthetic jet and dual synthetic jets on the separate flow of an airfoil.The results indicate that when the synthetic jet working,the angle of attack stall can increase by 2° and the maximum lift coefficient can increase by 18%,while the dual synthetic jets result in a increase by 4° and 35% separately.Therefore the dual synthetic jets have better performance on separate flow control.Parameter study is conducted to show the effects of forcing frequency and momentum coefficient of the dual synthetic jets on the aerodynamic performance.The results show that the optimum efficiency can be achieved when the frequency of the actuator is 1 and 2 times the characteristic frequency of the flow field,meanwhile the control is more efficient with the momentum coefficient increases.