SDBD等离子体增强双股矩形射流掺混性能实验研究

为提高姿轨控液体火箭发动机同轴式喷注器掺混性能，设计了简化的双股矩形射流发生器，开展了等离子体控制射流实验，获得了射流流场结构与速度分布，结果表明与单股射流类似，双股矩形射流同样具有很好的相似性，随着射流速度差的增大，相似性进一步增强，混合点逐渐靠近射流发生器出口，混合角和混合率增大，而涡量最大值减小；等离子体对射流相似性的影响较弱，主要增大了发生器出口附近的速度，缩短了射流核心区长度，增大了射流宽度和混合角，使得混合点位置移向发生器出口，扩大了高涡量值区域范围，不过3种实验工况下射流涡量和的正、负值均比较接近，混合率也非常接近，并且随着射流速度差的增大，等离子体控制效果降低；总的来说，等离子体激励器应安装在低速射流中，增大混合角比控制混合点位置对提高混合率更有效. 

Experimental Investigation on Improving Mixing Performance of Two-Rectangle Jet by SDBD Plasma

In order to improve the mixing performance of coaxial injectors for attitude and orbit control liquid rocket engine,a two-rectangle jet generator was designed.Then,the plasma flow control experiments were carried out to obtain the flowfield and velocity profile of jets.The results show that the two-rectangle jet has good similarity,which is similar to the single jet.When the velocity difference of two jets increases,the similarity gets better,and the mixing point moves to the generator exit.Meanwhile,the mixing angle and the mixing ratio increase,but the maximal value of vorticity decreases.The influence of plasma on the similarity is weak,but it can increase the jet velocity near the generator exit,the jet width and the mixing angle.It can also shorten the potential core length,make the mixing point move to the generator exit and expend the high vorticity domain.However,the positive and negative values of vorticity sum are about the same size,and their mixing ratios are close to each other.With the increase of jet velocity difference,the plasma control effect decreases.In general,the plasma actuator should be setted in the low-speed jet.Increasing the mixing angle is more effective than controlling the location of mixing point.