【摘要】 文中尝试并讨论了用于消减伪扩散的各种网格调整方法,并将数值结果与实验数据进行了对比。结果表明近流线的网格方法比较真实地反映了实际流场,贴体网格和O型网格可以成功用于切圆锅炉流场的计算。为了探讨网格在计算中的作用,计算了切向燃烧锅炉模拟中采用直角网格布置导致的伪扩散效应在炉膛的分布。理论分析和数值与实验间的比较结果表明,由于网格线的不合理布置导致的伪扩散误差是切向燃烧流场模拟中的主要误差。在炉膛空气入口附近的伪扩散效应会覆盖湍流黏性的作用,大约为物理湍流粘性的10～30倍,这样的作用容易导致不合理的模拟结果。更多还原

【Abstract】 Different meshes employed to simulate fluid flow in TFB(tangential fired boiler)were discussed and mesh methods to decrease crossflow diffusion were investigated.Numerical results were compared with experiments.Com-parisons show that simulation with body-fit mesh can obtain the more reasonable results.Body-fit mesh and O type mesh can be applied to simulate air flow in TFB successfully.Crossflow diffusion caused by grid lines in TFB is investigated.The crossflow diffusion coefficients distributions are calculated.Theoretical analysis and comparison between computational results and experiments show that crossflow diffusion caused by grid lines is the most important error and grid line justification is the effective way to decrease crossflow diffusion.Crossflow identification shows that this kind of false diffusion effect is about 10-30 times over the turbulent viscosity and will leads to unreasonable simulation results.更多还原