The Application Of The Discrete Vortex Method In The Flow Around Cylinders

The flow around the cylinders is a classic problem in fluid mechanics and it is of great importance to research the influence of arrangement of columns,Reynolds number and current incidence angles on the flow around cylinders,drag and lift force.The Computational Fluid Dynamics(CFD)suffers from the flaws of huge calculation amount and numerical dissipation.In this paper,the in-house codes based on the Discrete Vortex Method has been developed to simulate the flow around cylindes.At first,two different DVM are used to verify the accuracy of the discrete vortex method.Then the method is used to the two tandem cylinders and found that when the gap spacing is 2 and 3,the vortex shedding only occurs on the downstream cylinder,and the upstream cylinder drag coefficient is positive while the downstream cylinder drag coefficient is negative.When the gap spacing is 4,vortex shedding happenes on both cylinders and the drag coefficients of both cylinder are all positive.Then the simulations of the simplified tension leg platform model under the flows with different Reynolds numbers and current incidence angles show that the wake pattern of the tension leg platform is a typical 2S vortex pattern.Except 0 degree,the drag coefficient decreases with the Reynolds number and then keeps constant.