CFD DEPARTMENT

EFFECT OF AERO-DISC ON BLUNT CONE NOSE IN HYPERSONIC VEHICLES

Introduction:

Vehicles like space plane, reusable launch vehicles, missiles, interplanetary probes, which fly at supersonic and hypersonic speeds, usually employ blunt nosed bodies for deceleration and thermal management. The aerodynamic drag of high speed vehicles shows significant effects in the final performance of the vehicle due to formation of bow shock wave which, resulting high pressure region in the vicinity of the blunt body. A blunt nosed body creates a bow shock wave at high Mach number, which in turn produces very high pressure in the forward region of the fore body, leading to a high wave drag and aerodynamic heating during the atmospheric flight. The dynamic pressure on the surface of the blunt body can be substantially reduced by creating low pressure region in front of the blunt body. The use of the forward facing spike attached with the shape of a hemispherical blunt body appears to be most effective and simple to integrate the vehicle as compare with the focused energy deposition and telescopic aero disk. Blunt body creates a bow shock wave at high Mach number, which produces to very high in pressure in the forward region of the hemispherical region, which leads to increase of high wave drag and aerodynamic heating during the projectile’s flight through the atmosphere.

It is advantageous to have a vehicle with low drag coefficient in order to minimize the thrust required from propulsive system during the supersonic and hypersonic regime.

Geometry and Meshing:

 

Fig: CATIA design of blunted aero-disc on aero-spike (L=2D)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The different type of Aero disc such as Aero-spike shape and hemispherical  are designed for analysis.

The fig shows that tetrahedral meshing on hemispherical aero disc configuration.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Analysis:

 

The figure shows that Mach Number contour on hemispherical aero disc configuration.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The figure shows that Mach Number contour on hemispherical aero disc configuration.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Result:

From the results, we can see that blunted aero-disc on blunt cone nose give more reduction in drag compared to other configurations. Also from the temperature contour of different configurations it is evident that blunted aero spike has more efficiency in terms of heat transfer also. About 58% reduction in drag is obtained while using the blunted aero-disc configuration.