NUMERICAL SIMULATION OF THE FLOW AROUND AN AIRFOIL TYPE TRANSPORT VEHICLE NEAR THE GROUND

Abstract

The problem of modeling the flow around an airfoil type transport vehicle near the ground is considered. The flow around the vehicle is turbulent. Nowadays, the most advanced mathematical models of aerodynamics are based on the physical properties of a viscous compressible gas and are based on the Reynolds-averaged Navier – Stokes equations. Mathematical modeling of turbulent flows remains one of the most challenging problems. Reliable prediction of the characteristics of turbulent flows is an extremely important scientific problem. This is due to the complexity and insufficient study of turbulence as a physical phenomenon. The aim of this work is to build a mathematical model, a numerical method, an algorithm for solving the problem, and to develop software for studying the aerodynamic characteristics of a vehicle of the airfoil type. To close the Reynolds-averaged Navier –Stokes equations, the one-parameter Spalart – Allmaras turbulence model was used. The initial system of differential equations is written in a curved coordinate system. The initial and boundary conditions for the flow parameters are formulated. The methodology, algorithm for solving the problem, and software are developed. The finite-volume method was used for numerical integration of the system of differential equations. The problem was solved in a multi-block formulation. The developed methodology of algorithms and a set of programs were tested on standard aerodynamic problems: the flow around a transversely placed circular cylinder and a ball. Numerical modeling of the flow of compressed gas around a vehicle moving near the ground was performed. All calculations were carried out for the Reynolds number Re=1,0*10^6 and the Mach number M=0,4. Numerical simulations were performed on a curved multi-block grid. The influence of the ground on the characteristics of the flow around the vehicle was investigated. The studies have shown that the presence of a nearby ground has a significant impact on the flow characteristics around the vehicle. Thus, in order to ensure the required parameters of vehicle dynamics near the ground, it is necessary to take into account the influence of the ground on its aerodynamic characteristics.