两层粘性流体中圆柱体受迫振荡数值模拟

研究两层粘性流体中无限长水平圆柱体的受迫振荡问题。在湍流模式下,采用VOF方法追踪两层流体的内界面,基于动网格技术模拟圆柱体的运动边界,对均匀流中横向振荡圆柱体的绕流场进行了数值模拟。计算受迫振荡圆柱体的升力系数、阻力系数随时间的演化曲线和圆柱体的尾涡分布,以及圆柱体的受迫振荡激发两层流体内界面的扰动,并与均匀流体的情况进行了比较分析。研究表明,流体的两层分层效应对受迫振荡圆柱体的升阻力系数和尾涡分布特性都有显著影响,在水下输油气管道涡激振动特性的工程评估中,应考虑流体的密度分层效应。

Numerical simulation for the forced oscillation of flow past a cylinder in a viscous two-layer fluid

In the present work,the problem of flow around a circular cylinder oscillating transversely in a viscous two-layer fluid is considered under the turbulent mode,where the VOF method is used to track the interface of the two-layer fluid,and the dynamic mesh technology is used to simulate the moving boundary of the cylinder.The lift and drag coefficients changing with time are computed;moreover the wake vortex and the interfacial disturbance excited by the oscillating cylinder are numerically analyzed.The results are compared with the cases in a single-layer fluid,showing that the density stratification can have a relative large effect on the drag and lift coefficients as well as the vortex shedding.Therefore,it is of considerable importance to consider the effect of the density stratification on the hydrodynamics of offshore structures.