Numerical Investigation of Two-Dimensional Unsteady Laminar Flow over Rotating Triangular Cylinder in Free Stream

Oscillation or rotation rates change flow behavior and wake patterns over and around cylinders. In this study, laminar fluid flow over a rotational cylinder with triangular cross section is studied numerically. Because of rotating geometry, dynamic mesh is used for the numerical solution and simulations are done for 50,100,150,200 Reynolds numbers and 1, 2 and 3 rotation rates and effects of rotation rate and Reynolds numbers on wake and flow patterns are investigated. Investigating average Lift, drag and moment coefficients express that increasing in Reynolds number and rotation rate lead to lower lift and drag coefficients, while moment coefficient has a gradual growth similar to the circular cylinder case. However, the dependency on the Reynolds number is higher in a way that by increasing the rotation rate from 1 to 3 the change in the coefficients is at least 40 percent more than changes of coefficients due to tripling the Reynolds number.