In order to clarify the effect of core flow inlet preswirl angle of mixing exhaust system on the aerothermodynamic performance of splitter mixing exhaust system

investigation on the flow field of splitter mixing exhaust system at different inlet preswirl angles was carried through the three-dimensional numerical simulation based on Navier-Stokes equations

and the results were compared with flow along the axis. According to the results

the thickness of shear layer increases with the inlet preswirl angle

and it is the same with the twist of shear layer. Besides

at the splitter mixing exhaust system exit

as the inlet preswirl angle increases

the thermal mixing efficiency increase slightly and thermal mixing efficiency of 30 degree inlet preswirl angle model is 1.36 times the model with flow along the axis. Moreover

total pressure recovery coefficient and thrust of splitter mixing exhaust system also decline. Compared with the model with flow along the axis

the total pressure recovery coefficient of 30 degree inlet preswirl angle model falls by 0.0034 and its relative thrust declines by 0.081.