Numerical Analysis Of The Effect Of The Drag Reduction By Inserting An Airfoil In A Two-dimensional Cavity

With the rapid development of international economy , non- renewable energy decreases rapidly. In the future we might meet energy crisis . How to improve the utilization efficiency of energy and reduce energy losses, is one of the main scientific research topics.To research of drag reduction by the method computational fluid dynamics has the important theoretical and practical value.The paper adopts the pre-processing module GAMBIT for geometrical modeling of a 2D flat plate flow, 2D cavity flow with and without an airfoil in it .The unstructured and structured grids with reasonable distribution are used to mesh flow region. Numerical computations are carried out by using the commercial software FLUENT as working platform .The finite volume method is adopted to discret the equations in the numerical simulations,The velocity inlet condition and the outflow of boundary condition are adopted as the entrance and exit boundary condition respectively.The paper well simulate the 2D flat plate flow, 2D cavity flow with and without an airfoil in it by adopting the standard wall functions and uses standard K - e turbulent model with the relevant settings, and draw the flow field information of friction,velocity vector and pressure distribution about the three models.The effects of drag reduction are discussed by comparing the results of the three medels. Further numerical simulations on airfoil in different positions and the pitch angle are carried out ,and the results are analyzed and discussed about drag reduction effect when the airfoil positions and the pitching angles are different.The paper well simulates the 2D flat plate flow, 2D cavity flow with and without an airfoil in it, drawing the pressure distribution and the resistance coefficient curve, discussinging the total resistance changes when the airfoil positions and the pitching angles are different.By the computations and discussions of the 2D flat plate flow, 2D cavity flow with and without an airfoil in it,and the results of different positions and pitch angles,the following can be concluded: (1) The results show that the two-dimensional cavity flow with an airfoil in it is able to reduces the total resistance ,and the plays the role of drag reduction.(2) The results show that a reasonable place of an airfoil position and pitch angle can improve the efficiency of drag reduction.