Numerical Simulation On The Interaction Of The Flow With A Vertical Circular Cylinder

Vortex-induced vibrations often occur when the structures of the ocean engineering are cut by the flow, such as drill pump, oil and gas pipelines and marine riser. The special fluid-structure interaction causes large stresses and potential fatigue damage to the marine structures and reduces their construction and performance functions and affects the safety and capability of such systems. There have numerous research works on flow past a circular cylinder in the viscous uniform fluid by use of two-dimensional numerical simulation methods. However, such a problem has not been reported yet for the case of the three-dimensional simulation under supercritical Reynolds number.After an overview and summarization of the recent research progress, the paper focused on the interaction of the current with a vertical circular cylinder.In ChapterⅡ, based on the viscous flow theory, the mathematical and physical model to the VIV problem of a horizontal circular cylinder in a uniform fluid were established. The dynamic layering mesh method was used to simulate the motions of the vertical circular cylinder under the forced oscillations.In ChapterⅢ, based on the N-S equation, the dynamic layering mesh method was used to simulate the motions of the vertical circular cylinder under the forced oscillations in vicious flow. The k ?εmethod was employed for the numerical simulation. The comparison was made to the flow past a static cylinder.In ChapterⅣ, the problem of the viscous flow past a large diameter cylinder of the Spar platform under supercritical Reynolds number was considered. Based on the incompressible Navier-Stokes equation with the Smagorinsky-Lilly model, the LES method was employed. The three dimensional characteristics of the wake vortex generated by the large diameter cylinder were successfully simulated. Moreover, numerical results were given for the characteristics of the pressure and drag coefficients around the cylinder.In Chapter V, the problem of the viscous flow past an elastic cylinder under supercritical Reynolds number was simulated based on the incompressible Navier-Stokes equation with the Smagorinsky-Lilly model. Both the LES method and the dynamic implicit method were employed for the numerically simulation. The distortion of the cylinder duo the flow was taken into account.