小雷诺数下圆柱绕流的数值模拟

Numerical Simulation of Flow around Circular Cylinder with Small Reynolds Numbers

在不同的小雷诺数(Re<70)下,采用有限体积法对圆柱绕流流场中的反向对称漩涡进行了非定常流动的数值模拟。计算区域采用分块网格划分与结构化○型网格划分相结合的技术,重点讨论了反向对称漩涡的尺寸变化、横向涡致力变化及壁面上的压力、速度和应力分布规律。数值计算结果表明:存在两个特征雷诺数,在第一特征雷诺数范围内,流动定常,无漩涡存在;在第二特征雷诺数范围内,存在反向对称漩涡;反向对称漩涡的尺寸与雷诺数近似成线性关系变化;约在62°处,压力值与雷诺数无关;壁面上的速度均约在45.8°处达到最大,切应力均约在51.6°处达到最大。

The reverse symmetry eddy in unsteady flow around circular cylinder was numerically simulated based on the finite volume method with different little Reynolds numbers（Re〈70）.The calculation region was meshed by a combined technology,which is formed by multiblock grid and structurized O type grid.The dimension change and landscape orientation force change of the reverse symmetry eddy were researched with different little Reynolds numbers.Besides above aspects,The distribution laws of pressure,velocity and wall shear stress were also researched.The numerical simulation results show that there are two character Reynolds numbers in simulations.Within the first Reynolds number,the flow is steady and there is no any eddy.Within the second Reynolds number,there is a reverse symmetry eddy.The dimension of reverse symmetry eddy becomes the linear relationship change approximately with the Reynolds numbers.The pressures have nothing to do with the Reynolds numbers about 62°.The velocities and the wall shear stresses are all maximum respectively with the Reynolds numbers about 45.8° and 51.6°.