用RNG k-ε紊流模型对截止阀三维紊流流动的数值模拟

Numerical Simulation of a Turbulence Flow in the Cut-off Valve by RNG k-ε Turbulence Model

采用了RNG k-ε紊流模型和贴体坐标对截止阀对称面和三维流场进行了模拟,同时用粒子成像流速仪(PIV)对弯型截止阀对称面模型的测试结果和数值模拟结果进行了验证。数值模拟结果与实验结果吻合较好。实验和计算结果揭示了截止阀的流场特性,并说明截止阀水流产生的涡旋、分离流、二次流和强烈的紊动是截止阀水头损失的主要因素。计算结果表明斜进口截止阀流态好于弯型进口截止阀的流态,RNG k-ε紊流模型对具有分离和二次流的紊流流动具有较好的模拟性。

The RNG κ-ε turbulence model has been applied to simulate turbulent flows in symmetrical planes and in three dimensions of curved inlet cut-off valves, and its performance is compared to the results measured by a particle image velocimetry （PIV） in the experiments. The governing equations are solved in a body-fitted coordinate by finite volume method with staggered grid system. The computed results of curved inlet cut-off valve are in good ageement with the experimental data and show that the flow pattern of inclined inlet cut-off valve is much better than that of curved inlet cut-off valve. The predicted results also show that the RNG κ-ε turbulence model can be used to simdate the separated turbulent flows with vortices.