Simulation and Stability Study of the Flow Around a Cylinder in Infinite Domain

The flows around a cylinder in infinite domain are simulated using CFD method. The simulation results are found to be in agreement with the data in literatures. The flow stability is investigated with the energy gradient theory. It is found that the two zero velocity gradient points at lateral sides of the cylinder lead to flow instability which causes vortex shedding. The flow transition to turbulence are dominated by two aspects, i.e. the zero velocity gradient at the lateral sides of the cylinder, and the zero velocity gradient inner the region of the vortex in the cylinder wake.