Numerical Simulation of Vortex Shedding at Triangular Obstacle for Various Reynolds Numbers and Times with Open FOAM

Ahmad Jafari, Seyyedeh Zahra Malekhoseini

The present study aimed to simulate the two-dimensional flow around a triangular obstacle in a channel. Numerical study was performed by the open-source numerical model, OpenFOAM. IcoFoam solver was used to solve the equations governing the flow in the modeling. The Navier-Stokes and continuity equations are the dominant equations in this solver. In the first step, flow lines and velocity vectors were simulated for Reynolds numbers of 20, 30 and 35. The simulations showed that the separation of flow lines and the formation of vortex bubbles depend on the Reynolds number, even when this parameter slightly increases. In the second step, the flow lines at six different times with the time interval t/6 at Reynolds numbers of 150 and 200 were identified. Based on the results, it was indicated that only at the time of 150s a different pattern was observed for the flow lines. In the third step, as the Reynolds number increases, changes in the flow lines pattern were studied in a regime with Reynolds numbers of 4, 35, 70, 120 and 200, resulting in turbulence in the flow lines. To measure numerical stability during processing, the average and maximum values of Courant number were calculated at every stage of solution and implementation. The residual and velocity changes graphs were depicted based on location in the x-y plane to analyze the data. Finally, based on the verified results, the ability and power of the numerical model was evaluated and It is concluded that as an appropriate efficient model in this field.