Effect rules of aft propeller pitch angle on the performance of contra rotation propeller

The pitch angle of the contra rotation propeller (CRP) has important effect on the aerodynamic interference between the front and aft blades,which can change the aerodynamic performance of the propeller. In order to study the aerodynamic influence of pitch angle on the contra rotation propeller and improve the aerodynamic performance of propellers,at the inlet Mach number of 0.453,the numerical calculation is carried out by adjusting the blade pitch angle after about 6×6 configuration contra rotation propeller,in which the method is used by combining unsteady Reynolds-averaged Navier-Stokes (URANS) equation with SST turbulence model. The T-Rex high quality grid generation technique is used to study the change rule of the pitch angle of contra rotating propeller on aerodynamic interference. The results show that the aft propellers are under the action of pre-swirling air from the front propellers,the aft propellers can absorb a part of the tangential slip flow energy of the front propellers,and the aerodynamic efficiency is higher than that of the front propellers. The aerodynamic parameters of the front and aft propellers fluctuate 12 times in a rotating cycle. When the rotating speed of frond and aft propellers maintains the same,the pitch angle of the front propellers maintains constant,and the pitch angle of the aft propellers is reduced,the aerodynamic efficiency of the front and aft propellers is increased,and the efficiency of aft propellers is improved significantly