合成射流控制主流矢量的发展过程

合成射流激励器射流矢量控制具有对吸气式发动机进气道出流和发动机喷管流动进行矢量控制的潜力。通过对四种不同出口构型合成射流激励器控制主流矢量偏转的数值模拟和分析,对合成射流控制主流矢量的发展过程进行了研究。结果表明:合成射流控制主流矢量的发展过程可分为三个不同阶段,第一阶段,在主流通道内,激励器工作引起的主流通道压强梯度形成的侧向力致偏主流,在出口处主流矢量偏转Ⅰ;第二阶段,在主流出口附近,合成射流对主流的卷吸作用和引射作用,致偏主流Ⅱ;第三阶段,在出口下游,合成射流与主流自由剪切层发生相互耦合作用,致偏Ⅲ。因此,主射流最终偏转角度是其在经历三个不同阶段时受到的合成射流致偏作用之和,即=Ⅰ+Ⅱ+Ⅲ。

Evolution of vectoring control of a primary jet with synthetic jets*

The technique of jet vectoring using synthetic jets has a potential ability of thrust vectoring a primary jet,such as thrust vectoring controlling the inlet air jet and the nozzle jet of the air-breathing engine.To investigate the evolution of vectoring control of a primary jet with synthetic jets,a primary jet vectoring control using synthetic jet actuators with different exit configurations was numerically simulated and analyzed.The results show the evolution of jet vectoring using synthetic jets is divided into three stages.In the conduit of the primary jet,the low-pressure region,which results from the interaction between the synthetic jet and the primary jet,contributes to the vectoring force and leads to a turning of the primary jet at the conduit exit,and the primary jet turns φⅠ.And then,in the near field,the primary jet fluid is entrained and absorbed by the synthetic jet during the blowing and the suction stroke,and the primary jet turns φⅡ.Finally,in the far field,the shear layer of primary jet is inspirited by the vortices of synthetic jet,and the primary jet turns φⅢ.So the final vectoring angle of the primary jet is a overall result of the primary jet controlled by synthetic jet at the three stages,φ=φⅠ+φⅡ+φⅢ.