Numerical investigation on the external compressible ow around NACA m1 and NACA 0015 airfoils

The importance of the external ows around the airfoils became serious when the airplanes with high velocity crashed due to passing the critical Mach number. These events caused the signicance of the eects of the Mach number on the drag and lift force to become clear. In this paper, the modeling of two standard airfoils for dierent angles of attack and various Mach numbers are. The external ows around the airfoil are solved by two turbulence models which are Splalart-Alamaras and k-" models. Both of the airfoils have been modeled for Mach numbers from 0.8 to 1.2 and angle of attacks of 0 and 4 degrees. The pressure and drag coecients, pressure force for both top and bottom walls of the airfoils, are calculated by using the Spalart-Almaras and k-" models. The results show that the drag coecient increases intensively when the Mach number is equal to one, then for a determined Mach number, the drag coecient is stable. The drag force and coecient of the two above turbulence models in dierent Mach numbers are investigated, and the location of the shock wave phenomenon for the airfoils NACA m1 and NACA 0015, with dierent angle of attacks, is studied.