两相湍流的非线性k-ε-kp模型
A Non-Linear k-ε-kp Two-Phase Turbulence Model
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摘要: 由两相湍流的代数应力模型,提出一种两相湍流的非线性k-ε-kp模型,可以合理地模拟各向异性较强的旋流,浮力流等两相流动,具备二阶矩模型的优点,又比二阶矩模型简单。文中推导出气相、颗粒相的雷诺应力和两相脉动速度关联的非线性应力应变关系式。这些代数式和两相各自的湍动能k,kp以及两相脉动关联湍动能kpg的方程联立,就构成非线性k-ε-kp模型。本文将该模型用于模拟突扩湍流两相流动,给出两相时均速度场及雷诺应力各分量,并且将模拟结果和PDPA实验数据以及二阶矩模型的模拟结果对照。结果表明,该模型预报各向异性两相湍流的能力和二阶矩模型的能力接近,但是计算量比二阶矩模型的小得多。Abstract: A nonlinear k-ε-kp two phase turbulence model is proposed for simulating anisotropic turbulent two phase flows,such as swirling and buoyant flows.Non linear relationships of two phase stresses and two phase fluctuation velocity correlations with the strain rates are derived based on the two phase algebraic Reynolds stress expressions.The nonlinear k-ε-kp model is applied to simulating two phase sudden expansion flows and the results are compared with those obtained from the second order moment model,linear k-ε-kp model and experimental data.It is shown that the nonlinear k-ε-kp model is almost as good as the second order moment model but with much less computation time,and is obviously better than the linear k-ε-kp model in simulating anisotropic two phase turbulence.
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Key words:
- Two-phase flows /
- turbulence model /
- non-linear model
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