Developing of Numerical Solution Algorithms for Analysis of External Flows Around Cylinder

Abstract

Incompressible flows are an indispensable part of research issues in the area of aerodynamic and hydrodynamic. The main solution for incompressible Navier-Stocks equations are the spinfunction and initial variables methods, which is divided into two main categories including pressure based and artificial compressibility methods. In pressure based method, governing nonlinear equation are separated and then pressure Poisson equation based on momentum and continuity is formed. In this method, velocity and pressure fields are calculated by solving the momentum and pressure Poisson equations respectively. Considering a constant density through the incompressible flow is resulted in the absence of derivative termsin the continuity equation which causes a problem in integrating. In order to overcome these problems artificial compressibility method is utilized which adds an artificial derivative term in continuity equations, then the velocity and pressure fields are coupled. In this research, the effectiveness of pressure based and artificial compressibility methods are compared to analyze the external flows characteristics, in various Reynolds number. Developed approaches are validated by comparing previous researches. Simulation results indicate that artificial compressibility method base on characteristics gives more accurate solutions than pressure based method.