The aim of this report is to study the airfoil and all what concerns the lift. But it would pretentious to want to know all about plane wings, just by doing a simple numerical study. Results are obtained thanks to a CFD code called AVBP (Version 4.2) and developped by CERFACS.
The report will be decomposed in three parts. A first one is about the checking of some typical results of airfoils velocity fields. The numerical results are calculated for the Euler equations, in other words, the fluid is assumed perfect. The second part deals with the variation of incidence degree and so with the lift coefficient Cp. The third part will be about using Navier-Stockes equations for solving the airfoil problem. In this part the fluid is no more perfect and the grid used is more refined near the wing edges.
Airfoil profilesStrutured Grid
- Two models of airfoils are used. The main part of the project has been done with a NACA0012 profile and with 2 grids.
The strutured grid has to be used for Mach numbers close to 0.85. The second one is done for Mach numbers around 1.2. The presence of shocks in the airfoil flow creates some strong gradients in some positions (that is the subject of Part I) that depends on the Mach number. The grids having to be refined where gradients are high, grids are fonction of the Mach number and so are very different if M=0.85 or if M=1.2.
This mesh is especially done for airfoil resolution with Navier-Stockes equations. The fluid is viscous and gradients in the boundary layer are strong.
- A second model will be used in the third part. It is called Profile A of Aerospatiale. The grid is presented there.