PARAMETER ANALYSIS OF AERODYNAMIC DRAG FORCE IN STRATOSPHERIC AIRSHIP

To explore the influence of environmental parameters and shape layout on the aerodynamic drag force of a stratospheric airship, the parameters of wind velocity, dynamic viscosity coefficient, air density, Re, slenderness ratio and fins were studied based on the verified CFD numerical simulation method. And the influencing rule and mechanism of all the above parameters on aerodynamic drag forces were investigated by the constituent parts of aerodynamic drag forces that are differential pressure drag forces and frictional drag forces. The analytical results indicate that the aerodynamic drag force coefficient decreases as the increase of wind velocity and air density but increases as the increase of dynamic viscosity coefficient. The decreasing trend of the aerodynamic drag force coefficient as the Re depends on the decreasing trend of the frictional drag force coefficient. As the slenderness ratio increases, the frictional drag force coefficient appears an increase trend, but the aerodynamic drag force coefficient decreases at first and then increases. The effect of the fins on the aerodynamic drag force coefficient is mainly reflected in the change of the differential pressure drag force coefficient.