【作者】 李玉倩；

【导师】 何永森；

【作者基本信息】 湘潭大学 ， 计算数学， 2008， 硕士

【摘要】 用DLR型k-ε紊流模型·BFC（边界拟合曲线坐标变换）法,对扩散角为4°,扩散度为4的锥形渐扩管路系统内具有逆压梯度的充分发展的不可压粘性紊流进行数值仿真与诊断。应用实例的入口雷诺数分别为1.16×10⁵和2.93×10⁵。在近壁密集型径向适体非均匀网格系统下,通过36种算例的数值实验,研究模型函数f_μ和f₂的不同组合,改变网格布局,简化ε方程和压力泊松方程及改变每时间步的迭代次数I和时间步长Δt等条件对计算结果的影响,将计算结果与实验结果相比较,绘制出流场各流动参数的分布图。其中包括时均流速（?）,（?）,压力（?）,紊流动能k,紊流耗散率ε,涡动粘性系数v_t和壁面压力系数C_pw。对数值仿真的结果进行诊断分析,获得难以用实物实验或模型实验测得的相对精确的数据,为该种紊流理论的研究和工程应用提供比较可靠的参考依据。在文章的结尾,作者对本文所做的工作进行了总结和概括,并且指出了今后的研究工作。更多还原

【Abstract】 Fully developed incompressible viscous turbulent flow with adverse pressure gradient in a conical diffuser tube system having a divergence of 4°and an area ratio of 4 has been simulated and diagnosed by a DLR k-εturbulent model and it’s BFC（Boundary-Fitted Coordinate Transformation） method.The research has been done for pipe entry Reynolds number of 1.16×10⁵ and 2.93×10⁵.Based on the near wall denseness model radial fittedbody nonuniform grid system,The calculated results of 36 cases have been given under the different calculated conditions,such as different model function combinations,different grid dispositions,predigest theεfunction with pressure function and different I with different△t.They were compared with the experimental results respectively.The parameter distributions of the area have been given respectively,including the distributions of the mean flow velocity（?）（?）,mean pressure（?）,turbulent energy k,turbulent dissipationε, eddy kinematic viscosity v_t and the coefficient of wall pressure C_pw.The results of numerical simulation have been diagnosed in order to obtain the more accurately numerical prediction results,which haven’t been gotten by using material experiment and model experiment,the results have offered relatively credible reference for turbulent theoretical research and engineering technical actual application.At last,the researcher has been summarized this article and the work in the future have been put forward.更多还原