摘要
对圆孔射流近场的湍流特性进行直接数值模拟(DNS)研究,同时与应用雷诺时均方程的模拟方法(RANS)进行了对比研究。DNS模拟的Re=5000,计算网格3000万,CPU=60。采用MPI并行求解了可压缩的射流守恒方程,包括连续性方程、动量方程、能量方程和理想气体的状态方程。基于DNS数据库,着重研究和评价了RANS模型在预测自由圆孔射流近场湍流特性时存在的问题,同时提出了适用于射流近场湍流粘性系数的分段表达式,可为工程上准确预测湍流切应力提供参考。
DNS and RANS calculations of jet round flow in near field region were campared.In the DNS calculations,the Reynolds number was about 5000,and the total grids used was about 30 million.The compressible Navier-Stokes equations were solved including the continuity,momentum,energy and perfect gas state equations in order to give a clear understanding of the jet development in the near-field region.Based on the DNS database,the problem in the RANS model when the model was used to predict the turbulence character in the near filed region of the jet round flow was investigated and evaluated,then a new function of turbulent viscosity used in the near filed region of jet round flow was obtained,so it can be predicted that the turbulent shear stress more precise in the project.
出处
《能源工程》
2010年第5期1-6,共6页
Energy Engineering
基金
国家自然科学基金资助项目(50736006
50976098)
