Numerical investigation of performance of a training airplane in developed spin conditions

Spin is one of the most important phases of aircraft design. Therefore one of the important tests for taking the pilot certification is entry and recovery from spin. The spin of PC-21 is investigated numerically and theoretically at the developed spin phase and is compared with results of flight test. The spin type of this airplane is counterclockwise and maximum rudder deflection is 25 degree. According to theoretical results, the spin of this aircraft should be happen at angle of attack 30 degree; however the flight test results show that spin must be happen at angle of attacks between 40 to 65 degrees. Numerical results show good agreement with flight test data. This research describes the ability of computational fluid dynamics to prediction of the behavior of airplanes in the spin conditions. The proper turbulence modeling, strong hardware, accuracy evaluation and significant experience in CFD procedures are requirements of the approach.