The Application Of Computational Fluid Dynamics In Airfoil Design And Water Treatment

The main aim of Computational Fluid Dynamics(CFD for short)is to get the rational numerical result by Simulating the fluid experiment with computer.In view of its high effectiveness and constantly improved accuracy,CFD has attracted so much attention that its applications are becoming more and more extensive.In this dissertation,two excellent soft wares of CFD are used to investigate airfoil design and water treatment.Some beneficial conclusions are derived from the numerical results.Firstly,the three control equations and their universal form in fluid dynamics were introduced.And the working flow of CFD was also described.Secondly,with the knowledge of the Aerodynamics and Zhukovski Transformation,we found the relation betweeen the geometrical parameter of initial airfoil and lift coefficient(c_L),Based on which four symmetrical airfoils were presented.Then,with the help of XFOIL,which is one of CFD soft wares,we obtained the c_L and Lift-to-Drag Ratio(c_L/c_D) at the different Reynolds numbers and attack angles.The results showed that the aerodynamic performance of the airfoil could be improved when properly added its thickness.Then based on the better airfoil,we change the camber of airfoil and compare the NACA airfoils with the same thickness and camber by using XFOIL.So we can know that our airfoil is better than NACA on the aerodynamic performance.Next,we study the Vertical Axis Wind Turbine(VAWT) about the starting wind speed using FLUENT, we find that the starting performance of our airfoil is so good at low wind speed(2.2m/s).Finally,we study another hot research field about CFD——the application of water treatment technology.In the beginning,we test the pressure with water in order to provide data for simulation.Then we simulate the flow fileds near the multiple hole orifice plate by using the FLUENT.The distribution of absolute pressure is obtained. Latter,in the water treatment experiment,we investigate the relation between the downstream pressure and the RB degradation.The experimental result indicate that collapse phenomena is very important factor for cavitation.