不同入射角横向紊动射流流场的数值模拟

A Numerical Simulation in Turbulent Jet into the Transflow with Different Injection Angles

采用RNGk-ε湍流模型和标准k-ε对射流出射角度α=25°、35°、45°的横向紊动射流流场进行了数值模拟,结合SIMPLEC算法求解了适体坐标系下的控制方程,近壁区流动采用两层模型的壁面函数法处理,结果给出了射流与主气流速度比M为4、6和8时的速度场和湍动能。结果表明:M和α值是影响横向紊动射流的重要因素,M值增加,射流对主流场影响区域增加,α值变化,射流对主流场上游影响区域较大;并且通过与实验数值的比较,发现RNGk-ε模型对横向紊动射流流场的预测能力比标准k-ε模型有所改进。

By using the RNG κ-ε turbulence model numerical simulations were performed to investigate the characteristics of Turbulent Jet Into the Transflow, at the jet injection angles of 25,35,45deg. The SIMPLEC algorithm in the body-fitted coordinates and the modified wall function method, two-layer model, was adopted to simulate the flow in the near-wall region and the outer core flow, at two jet-to-crossflow velocity ratios, 2,6 and 4. The turbulent kinetic energy fields jet trajectories and the velocity fields were given. It can be concluded that, when the jet is injected at positive angles, the initial section of the jet increases and the region affected by the jet decreases in the vertical direction; moreover, the circumfluence toward the jet exit becomes more obvious, and the separation events in the lee of the jet weaken;the prediction performance of the RNGK - ε model is better when simulating the turbulent lets in cross-flow.