论文标题
使用Vortex Generator Microjets在弯曲坡道上控制流动分离
Controlling Flow Separation over a Curved Ramp Using Vortex Generator Microjets
论文作者
论文摘要
将流体微喷气引入边界层以增加流体动量，因此延迟分离是积极控制流动分离区域的一种方法。目前的工作通过数值分析了坡道后面的分离气泡的控制。为此，我们首先验证了坡道上流动（无喷射）的数值结果，以针对文献的可靠实验研究。接下来，还验证了将微喷气引入流量的效果。然后将射流放置在坡道上方三个不同的距离处，以研究其对各种参数的影响，包括速度，雷诺应力，压力，涡流，流线和分离气泡大小。随着喷气机的向后移动，喷气引起的上洗区域的增长大大增长。最后，研究了使用三个相同的喷气机的效果，并将其与单射流的效果进行了比较。结果表明，使用三射流阵列缩小了分离气泡。使用d/d = 15的阵列可以横向限制分离气泡在z方向上的单个射流小的2.75倍。同样，在LX/L1 = 0.0143和D/D = 10的情况下，射流的使用将X方向的分离区的长度降低到78％。
Introducing a fluid microjet into the boundary layer to increase fluid momentum and hence delay separation is a method for actively controlling a flow separation region. The present work numerically analyzed the control of a separation bubble behind a ramp. For this purpose, we first verified the numerical results for a flow (without a jet) over the ramp against reliable experimental studies from the literature. Next, the effects of introducing a microjet to the flow were also verified. A jet was then placed at three different distances above the ramp to study its impact on various parameters, including velocities, Reynolds stresses, pressure, vorticity, streamlines, and the separation bubble size. As the jet was moved further back, the jet-induced upwash region grew considerably. Finally, the effects of using three identical jets were studied and compared against those of a single jet. The results indicated that using a three-jet array shrank the separation bubble. Using an array with d/D = 15 can limit laterally the separation bubble about 2.75 times smaller than a single jet in the z-direction. Also, the employment of the jet managed to decrease the length of the separation zone in the x-direction up to 78%, in the case of Lx/L1 = 0.0143 and d/D = 10.
