Two-dimensional Non-stationary Ns Equations And Two-equation Turbulence Model Coupled Solution Of Technical Studies,

In modern aircraft design, there is a pressing demand for accurate, efficient and applied aerodynamic data and computational analysis tools. However, the Euler equations are not satisfied all the requirement for simulating the precision of aeroelastic problems. It's necessary to solve N-S equations to simulate viscous effects, offer more accurate and more detailed flow-fields information. It is possible to solve N-S equations with the improvement of the hardware and software in computer fields, and the development of numeric methods in computational fluid dynamics domains.The present work is mainly focused on developing airfoils numerical simulation methods for steady and unsteady transonic flow. With the numerical solution of RANS equations, the applications of B-L zero-equation , k-ε and k-ω two-equation linear eddy turbulence models are discussed.On the basis of a finite volume method, the spatial discrete scheme about the convection terms of N-S equations: the Van Leer scheme of flux vector splitting, is studied. To get higher order accuracy,well stability and astringency, the MUSCL interpolation function and the continuous differential van Albada limiter are applied for Van Leer. In this paper, two time stepping schemes, explicit four-stage Runge-Kutta scheme and implicit LU-SGS scheme, are employed to solve the governing equations. Boundary conditions are treated by adopting "ghost" cells, thecomputational efficiency is improved and the program's complexity is reduced, too. In aircraft design, accurate numerical simulation for steady and unsteady flows.especially for transonic flows, is a crucial problem for designers. To confirm the validity and reliability of developed flow solvers, test cases of steady viscous flows around NACA0012 and RAE2822 airfoils, are given in this paper. On the base of steady computation, unsteady viscous flows about NACA0012 airfoil, are simulated. The structured viscous grid is used. The unsteady viscous motorial grid is fixed relative to airfoils. Numerical results are in good agreement with the experimental data. The method and the procedure presented in this dissertation are verified.