Flow Field Calculation Of Aircraft High-lift Devices Based On LBM-LES Method

High-lift device is one of very important components for civil aircraft, it is key one to enhance the performance of take-off and landing. High-lift devices have more complicated shape, therefore it is a very complex flow during take-off and landing time, which has heavy effect on the payload, fuel consumption and airframe noise(especially for noise from flaps and slats due to unsteady flow), and it even endangers safety of aircrafts.To provide a new method and technology for numerically simulating complex flows of high-lift devices, a coupled method between LBM and LES is developed in the paper. The main idea of the LBM/LES method is to use the Smagorinsky model of LES to calculate turbulent viscosity, and thus relaxation factor could change along with the viscosity coefficient, which can improve the ability of LBM to calculate high Reynolds number flow fields; to save the computational cost, mesh generation technology based on Boolean variable controlling is also studied in this paper, and it is suitable for the standard LBM model.In order to further validate the present LBM/LES method, it is applied into a series of numerical simulations for classic flow problems. Flow fields for driven flow of cavity, flow around cylinder, NACA0012 airfoil and 30P30 N are calculated to further show the ability of LBM/LES for simulating flow phenomena. Results demonstrate that good agreements are obtained between results from LBM/LES method and experiment, therefore the coupled method is scientific and effective. Due to its own advantage, this new scientific method can effectively solve the complex flow field simulation problems.