Eventos Anais de eventos
ENCIT 2018
Brazilian Congress of Thermal Sciences and Engineering
NUMERICAL SIMULATION OF THE TWO-DIMENSIONAL INCOMPRESSIBLE FLOW AROUND ELLIPTIC CYLINDERS USING THE VORTEX METHOD
Submission Author:
Rodrigo Pereira , RJ
Co-Authors:
Vanessa Guedes, Rodrigo Pereira, Carolina Magalhaes, Gustavo Cesar Rachid Bodstein
doi://10.26678/ABCM.ENCIT2018.CIT18-0422
Abstract
External incompressible flows around bluff bodies are characterized by different regimes that depend mainly on the body geometry and the value of the Reynolds number, ranging from steady Stokes-type flows to strongly unsteady turbulent flows. For large Reynolds numbers a Von Karman-type periodic wake is formed as a result of boundary layer separation and vortex shedding. In this the mesh-free two-dimensional vortex method utilized to simulate two-dimensional, incompressible, unsteady flows taken into account for obtaining the numerical results is discussed. Flow around bluff bodies, in specific around circular cylinders, are also important for testing numerical algorithms. A comparison with experimental and other numerical studies of flow from the literature is made to validate the algorithm. Lamb vortices are generated near the cylinder surface, whose strengths are determined to ensure that the no-slip condition is satisfied and that circulation is conserved. The impermeability condition is imposed through the application of a source panel method, so that mass conservation is explicitly enforced. The vorticity dynamics of the body wake is computed using the convection-diffusion splitting algorithm, where diffusion is simulated using the random walk method and convection is carried out with a lagrangian second-order time-marching scheme. Results for the time history of the aerodynamic coefficients on the body surface are presented and compared to other results available in the literature, showing good agreement.
Keywords
Incompressible Flow, Elliptic Cylinder, Vortex Method, panel method, High Reynolds Number
