An Analysis of a Second Grade Viscoelastic Fluid Past a Cavity in a Horizontal Channel

• Main Authors: Tzan-Wei Wang, 王贊維
• Other Authors: Cheng-Hsing Hsu
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/37186316460150446333

碩士 === 中原大學 === 機械工程研究所 === 97 === This text studies second grade viscoelastic fluid past a cavity in a horizontal channel. By changing Reynolds number, elastic coefficient and cavity length, various flow patterns were studied. The results of the steady state viscoelastic fluid flow characteristics were obtained. A finite difference method was used to discretize the vorticity and stream function equations. The Gauss-Seidel method with successive over relaxation (SOR) was implemented in the difference equation to obtain the solutions. The analysis the reveals that by changing the elasticity coefficient and Reynolds number, the recirculation height reduces in the cavity. The flow patterns were shown and drifted in the cavity due to the influence of the Reynolds number and the elastic coefficient. When the height of the recirculation at the backward-facing step is higher than that at the forward-facing step of the cavity, we categorized this flow pattern as the first kind of the cavity flow. On the contrary, when the height of the recirculation at the forward-facing step is higher than that at the backward-facing step of the cavity, the flow pattern was termed the second-kind flow pattern. Third kind of the flow was present when both heights are equal. The results showed that the first kind flow pattern was occurred when the Reynolds number and the elastic coefficient were smaller than some critical numbers.