Numerical study of flow past in a rotating elliptical cylinder for re=5000

Abstract

Using OpenFOAM software to carry out numerical simulations, it is possible to study a turbulent flow around a rotating elliptical cylinder with a fixed Reynolds number of 5000, varying the aspect ratio from 1 to 0.25. In simulations with the rotational elliptical cylind er in 2D, it is necessary to use a dynamic mesh, therefore, it is necessary to create a cell zone and baffles (to allow it to be possible to define the boundary conditions on the faces of the region) for the rotating zone, in order to have an Arbitrary Mes h Interface (AMI) allowing to define that the mesh represented by the rotating zone will be able to move freely and at the same time communicate with the rest of the domain. The chosen turbulence model is k omega SST . The solver chosen was PIMPLE (pimpleFo am). The moment equations were solved using the second order upwind method (linearUpwindV grad(U)). For a temporal discretization of an implicit first order method, it was chosen (Euler). A changeable TimeStep was used to keep the Courant number below 0.5. The velocity ratio of the cylinder, what is in the range of 0 ≤ α ≤ 3, it induces a change in the distribution of pressure lines and at the point of stagnation, due to rotational movement in symmetrical bodies arises the lift force in also known as Magnus effect. In preliminary results it is possible to observe a periodic behavior, with maximum and minimum value for both lift force and drag force. Understanding this periodic phenomenon of the drag force and the lift force, study the values of relation cl / cd (lift coefficient divided by the drag coefficient) and knowing the influence of the velocity ratio in the cylinder aerodynamic forces is important in the feasibility analysis of the application of the Magnus effect in the engineering projects.