MATHEMATICAL MODELING OF THE INFLUENCE OF THE SPATIAL POSITION OF A HIGH-SPEED GROUND VEHICLE ON ITS AERODYNAMIC CHARACTERISTICS
DOI:
https://doi.org/10.32782/KNTU2618-0340/2020.3.2-2.25Keywords:
aerodynamics of transport vehicles, numerical modeling, CFD, Reynolds averaged Navier-Stokes equations, turbulence modelsAbstract
The problem of modeling the aerodynamics of a high-speed ground vehicle is considered. Mathematical modeling of the aerodynamics of transport vehicles is a rather complex and urgent task. Today, the most advanced mathematical models of aerodynamics are based on the physical properties of a viscous compressible gas and are based on the Navier-Stokes equations. Real currents around transport vehicles are turbulent. To date, there are no universal mathematical models of turbulence in computational aerodynamics. Calculation of such flows remains one of the most difficult problems. Reliable prediction of the characteristics of turbulent flows is an extremely important scientific problem and is associated with 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 creating software for studying the aerodynamic characteristics of a high-speed land vehicle of the Maglev type.
The article deals with the problem of modeling the aerodynamics of a high-speed ground vehicle. To describe the flow around the vehicle, the Reynolds-averaged Navier-Stokes equations are used. To close the Reynolds-averaged Navier-Stokes equations, Menter's two-parameter SST turbulence model is used.
The SST model is superior in quality to a number of other turbulence models, but is inferior to models with one equation in terms of computational simplicity and cost.
A methodology, an algorithm for solving the problem, and software have been developed. For the numerical integration of the system of differential equations, a finite-volume method was used. The problem was solved in a multi-unit setting. The developed technique was tested on standard aerodynamic problems.
Numerical modeling of the aerodynamic characteristics of a high-speed ground vehicle has been performed. All measurements were carried out for the Reynolds number
Re = 3.8 × 106 and the Mach number M = 0.15. The numerical modeling was carried out on a hexahedral many blocks computational grid, which was stored at 3.3 million universities. The influence of the spatial position of the hull of a high-speed ground vehicle relative to the road structure on aerodynamic characteristics has been investigated. The studies carried out have shown that the value of the angle of installation of the vehicle relative to the road structure significantly changes its aerodynamic characteristics. Further analysis of theoretical and practical research shows that aerodynamic characteristics have a significant impact on the dynamics of a high-speed vehicle. Thus, to ensure the required parameters of the dynamics of the high-speed ground vehicle, it is necessary to take into account its aerodynamic characteristics.
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