Yu. A. Vinogradov

Effect of vortex flows at surface with hollow-type relief on heat transfer coefficients and equilibrium temperature in supersonic flow

Abstract This paper deals with the results of experimental investigation of supersonic flow stream lining of the surface, which has relief looking as series of spherical hollows. Using thermography method the temperature fields on the surface are obtained at Mach numbers of the flow between 2 and 3. The study of these fields at unsteady conditions allows obtaining distributions of local coefficients of heat transfer. The coefficients of equilibrium temperature in different surface regions are determined by temperature fields. It is shown that the availability of spherical hollows relief on the surface not only intensifies heat transfer but also leads to decrease of recovery equilibrium temperature coefficients. The structure of the flow at flow along of the surface with series of hollows relief is studied by visualization. The nature of shadgraph indicates vortexes outgoing from hollows to flow core.

On the Shape of an Impact Crater at High-Speed Impacts

This paper presents the results of an experimental study on the geometric parameters of craters that originated at the impact interaction of polyethylene projectiles with a massive organic-glass target. The impactor speed ranged from 2.7 to 6.28 km/s. The shapes of the resulting craters are determined. Using statistical analysis and scaling theory, we obtained the dependence of the diameter and depth of the crater on defining parameters. The critical impact energy resulting in the catastrophic breakup of the target is estimated.

Experimental Investigation of the Penetration of Solids into a Target of Organic Glass under Impact at Velocities from 0.7 to 2.1 km/s

The results are given of experimental investigations of the interaction between spherical metal impactors and a target of organic glass. The impact velocities range from 0.7 to 2.1 km/s. Singular features of the pattern of penetration of impactors into the target are revealed. The empirical dependence of the depth of penetration on the impact energy is obtained, and comparison is made with the known formulas for superdeep penetration. An expression is derived for the limiting velocity, above which no formation of channels in the target occurs, but the impactor is completely destroyed and a crater is formed.

Destruction of organic glass under high-velocity impact

The results are given of experimental investigations of the interaction between a 2.5-g polyethylene impactor and a massive target of organic glass. The impact velocity ranges from 1 to 3.2 km/s. A statistical analysis is made of masses and sizes of fragments of the impact and spallation craters of the target.