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采用实验和大涡模拟对喷嘴出口雷诺数(Re=U0hρ/μ,其中U0为出口平均速度,h为平面喷嘴出口狭缝高度,ρ和μ分别为流体的密度与动力黏度)为25—10000,喷嘴间距L为4h—40h范围内的平面撞击流偏斜振荡特性进行了研究.通过对平面撞击流模拟和实验的结果进行比较,验证了数值模拟的可靠性,并对平面撞击流发生偏斜振荡的无因次参数(喷嘴间距L/h与出口雷诺数Re)范围进行划分,重点考察了湍流平面撞击流的偏斜振荡周期及速度-压力变化特征.研究结果表明大涡模拟能对平面撞击流的偏斜振荡进行有效预报;当平面撞击流发生周期性偏斜振荡时,特定点的压力与速度也发生周期性变化,且变化周期与偏斜振荡周期一致,偏斜振荡本质上是由速度-压力的周期性变化和转换引起的.
The Reynolds number (Re = U0hρ / μ, where U0 is the exit average velocity, h is the exit height of the plane nozzle, ρ and μ are the fluid density and dynamic viscosity, respectively) are 25-10000 , And the nozzle spacing L is 4h-40h. The simulation results of the plane impact flow are compared with those of the experimental results. The reliability of the numerical simulation is verified and the plane impact flow is biased The non-dimensional parameters of oblique oscillations (nozzle spacing L / h and outlet Reynolds number Re) are divided into two parts, focusing on the characteristics of the periodic oscillation and velocity-pressure variation of the turbulent planar impinging stream. The results show that the large eddy simulation When the plane impact flow periodic skew oscillation occurs, the pressure and velocity at a specific point also periodically change, and the variation period is consistent with the skew oscillation period. The skew oscillation is essentially It is caused by the cyclical changes in velocity and pressure and the transitions.