环状喷口对底排尾部流场影响的数值模拟

为了增强底排尾部流场中增压减阻的效果,提出一种环状喷口模型。采用有限体积法编程求解二维轴对称Navier-Stokes方程,对底排尾部流场进行数值模拟。数值模拟和底排实验进行对比验证,结果较吻合。在此基础上,数值研究环状喷口对底排尾部流场的影响。结果表明,随排气参数增大,环状喷口模型的底压始终高于圆孔喷口模型的底压。和圆孔喷口相比,环状喷口能削弱环状回流区,使底排气体更容易流入剪切层,避免引射现象的发生。环状喷口越靠近底部边缘,底排的增压减阻效果越好。

Numerical Simulation on Effects of Annular Jet in Base Flow of Base Bleed

An annular jet model was proposed to improve the turbo-charge and anti-drag effect of base bleed in tail flow field. Two-dimensional axisymmetric Navier-Stokes equations was computed using a finite volume scheme, and the tail flow field of base bleed was simulated. The simulation results were validated with experimental data well. Based this, the influence annular jet upon the tail flow field of base bleed was investigated. Results show that the base pressure of annular jet model is always higher than that of circular jet model with the increase of the injection parameters. Compared with circular jet, annular jet can weaken the strength of annulus recirculation. It makes bleed gases flow into the shear layer more easily and can avoid the occurrence of the ejector. The smaller the distance between the annular jet and the base edge, the better the benefits of base bleed.