标题: | 雷诺数对三维顶部驱动矩形槽中涡漩结构的影响 Effect of Reynolds Number on the Vortical Structures in a Three-Dimensional, Lid-Driven Cavity Flow |
作者: | 陈盈良 Chen Ying Liang 蔡武廷 Tsai Wu Ting 土木工程学系 |
关键字: | 雷诺数;TGL-涡漩;凹穴流;Reynolds number;TGL-vortex;cavity flow |
公开日期: | 2001 |
摘要: | 摘 要 本研究探讨一初始为静止之三维矩形槽,受突起之顶部驱动速度而形成之不可压缩流场,其雷诺数对此流场涡漩结构之影响。利用数值解析连续方程式与Navier-Stokes方程组,满足速度无滑移边界条件与压力Neumann型边界条件,以求得三维顶部驱动矩形槽流场之速度项与压力项。再由所推求出之速度项与压力项,计算流场之涡度场,而藉由上述所得之数值计算结果,绘出流场之速度向量图、涡度等值线图与涡度等值面图。并进一步由所绘出之图,探讨流场运动中雷诺数对于涡漩结构变化之影响;以及观察涡漩结构产生变化后,对于流场运动所产生之扰动现象。研究结果显示:此流场之涡漩结构会随着流场雷诺数的不同,而明显的由二维涡漩结构演化成三维特有之涡漩结构。且于Re=1300后,此三维涡漩结构始有明显存在于流场中,并演变为持续发展之流场特征,而非稳态之流场运动。此三维涡漩结构的产生,也同时为流场带来不稳定的影响,而使得流场发生具有波浪形扰动之特征,并随着雷诺数的增大,此不稳定现象更加剧烈地出现于流场中。 Abstract The purpose of the present research is to investigate the effect of Reynolds number on the vortical structure in a three-dimensional cavity. This cavity flow is incompressible and it is stationary in the beginning. The primitive velocities and pressure in a set of incompressible continuity and Navier-Stokes equations are solved using the finite difference method. The velocity boundary conditions are no-slip and the pressure satisfies the Neumann boundary condition. By numerical computations, the plots of velocity vector, vorticity iso-line and vorticity iso-surface are illustrated. Then the effect of Reynolds number on the vortical structure variations and wavy disturbances in the spanwise direction are shown through these plots. The results of this study reveal that raising of the Reynolds number makes two-dimensional vortical structure will evolve into three-dimensional structure. As the Reynolds number reaches 1300, the three-dimensional vortical structure starts to exist obviously in the flow field. This flow is not a steady motion, and it will continue to become a turbulence flow with the increase of Reynolds numbers. |
URI: | http://140.113.39.130/cdrfb3/record/nctu/#NT900015074 http://hdl.handle.net/11536/68115 |
显示于类别: | Thesis |