论文部分内容阅读
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。
Based on the algebraic stress model of two-phase turbulence, a nonlinear k-ε-kp model of two-phase turbulence is proposed, which can reasonably simulate two-phase flow with strong anisotropy, such as swirling flow and buoyancy flow. The advantages of the second-order moment model are simpler. In this paper, the nonlinear stress-strain relationship of gas phase, Reynolds stress of particle phase and two-phase pulsation velocity are deduced. These algebraic equations and the two-phase turbulent kinetic energy k, kp and the two-phase pulsation-associated turbulent kinetic energy kpg are combined to form the nonlinear k-ε-kp model. In this paper, the model is used to simulate turbulent two-phase flow with sudden expansion. The two-phase mean velocity field and components of Reynolds stress are given. The simulation results are compared with the experimental data of PDPA and the simulation results of the second moment model. The results show that the capability of this model to predict anisotropic two-phase turbulence is close to that of the second moment model, but the computational complexity is much smaller than that of the second moment model.