颗粒增强湍流的新模型和气粒流动的湍流变动

A NEW GAS TURBULENCE ENHANCEMENT MODEL BY PARTICLES AND TURBULENCE MODULATION IN GAS-PARTICLE FLOWS

用雷诺应力方程模型和极细的网格系对单个颗粒受湍流气体绕流进行了数值模拟,研究了改变颗粒直径和气体相对速度时颗粒增强气体湍流的规律。据此构造了颗粒尾涡增强气体湍流的新模型。将此子模型加入到两相流动模型中,对竖直和水平通道内气粒两相流动进行了数值模拟,和实验结果的对照表明,考虑颗粒尾涡增强气体湍流效应得到的气体湍流脉动速度的模拟结果比不考虑此效应的模拟结果好得多。

Simulation of gas turbulent flows passing a single particle was carried out using a Reynolds stress equation turbulence model and very fine grid nodes. The turbulence enhancement by the particle wake effect was studied under various particle diameters and gas relative velocities. A new turbulence enhancement model is proposed. This sub-model is incorporated into the two-phase flow model and is used to simulate gas-particle vertical pipe flows and horizontal channel flows. Comparison with the experimental results shows that the simulation results of gas turbulence accounting for the particle wake effect are much better than those obtained using the model not accounting for this effect.