非正交曲线系下数值模拟及PDA测量模化炉内湍流流场  

Turbulent Flow Calculation in NonOrthogonal Curvilinear CoOrdinates and Its Measurement by PDA in a Model Furnace

作　　者：郑昌浩[1] 徐旭常[1] 王晓 李彦[1] 

机构地区：[1]清华大学煤的清洁燃烧技术国家重点实验室,北京100084

出　　处：《燃烧科学与技术》2002年第5期431-436,共6页Journal of Combustion Science and Technology

摘　　要：构造强守恒形式N S离散方程组,耦合求解速度和压力修正方程,k ε双方程模型模拟湍流粘性。在方程离散中,采用以加权平均方法计算胞元界面上不连续的几何因子,以保持坐标转换的光滑性;以迭代方式考虑交错压力梯度项,并对常规形式压力方程结果进行二次修正。计算结果表明,针对局部非光滑且远离正交性的炉内网格体系,上述特殊数值方法对保证求解精度和收敛性具有关键作用。采用3D PDA(三维激光多谱勒固粒运动分析仪)对670t/h四角切圆炉的1:20模型内冷态流场进行了测量。数值模拟结果与实验结果基本吻合。NS equations are written in strong conservative form,and the resulting conservation equations are solved with pressurevelocity coupling method.kε model with wallfunction approach are involved in turbulence simulation.In order to maintain the smoothness properties of the curvilinear coordinate mapping,weightedaverage method is employed to calculate discontinuous geometrical factors in the cell surface for discretizing the governing equations.The crossderivative pressure terms are considered with iterative method,and intermediate results of commonly used pressure equation are corrected for the second time.The computational results prove that for locally nonorthogonal meshesused in present study,the special numeric techniques mentioned above play a key role in guaranteeing the accuracy of the calculation and preventing convergence problem from occurring.The fluid flow field is measured by 3DPDA (3Dpatical dynamics analyzer)for the 1:20 model of a 670 t/h tangentiallyfired boiler.The numerical results are in general agreement with the experimental ones.

关 键 词：非正交曲线系 数值模拟 PDA测量 模化炉 湍流流场 炉膛 四角切圆锅炉 坐标系 几何因子 坐标变换 交错压力梯度项 

分 类 号：TK223.2[动力工程及工程热物理—动力机械及工程]