TURBULENT WAKE AND SHOCK SHAPE OF HYPERVELOCITY SPHERES
Abstract
Experiments were conducted to study some of the properties of the inner turbulent wake behind high speed spheres in free flight over a wide range of velocity and pressure. Schlieren and shadowgraph techniques were used to photograph the wake. It was shown that the growth of the inner wake close to the body is a function of velocity and ambient pressure. In the very far wake it was shown experimentally that wake growth follows a 1/3 power law independent of velocity and ambient pressure. Experimental measurements of the location of transition from laminar to turbulent flow in the inner viscous wake were shown to be dependent upon unit Reynolds number. Approximate axial velocity distributions in the inner viscous wake were measured with oblique doppler radar techniques and a schlieren drum camera system. These two systems measure such widely different velocities that it was concluded that they measure the velocity at different radial positions in a wake which has strong radial gradients in velocity. Finally, a study of the shock shape for spheres for a wide range of pressure and velocity showed that the shape is dependent upon Mach number rather than velocity and is independent of ambient pressure. This comment does not apply to the standoff distance.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1966
- Accession Number
- AD0484821
Entities
People
- A. B. Bailey
Organizations
- Arnold Engineering Development Complex