Accession Number : AD0427082


Title :   THEORY OF LIQUID ABLATION,


Corporate Author : ARMY MISSILE COMMAND REDSTONE ARSENAL ALA PHYSICAL SCIENCES LAB


Personal Author(s) : Steverding,B


Report Date : 22 Oct 1963


Pagination or Media Count : 43


Abstract : The consideration of surface phenomena in ablation processes leads to several substantial additions and corrections in the present ''classic'' theory of liquid ablation. The phenomenon of aerodynamic spattering in the ablation of liquid films is closely related to the surface tension. Spattering will not always decrease the ablation efficiency. With ''ideal'' spattering this efficiency may even be increased. Ideal spattering, however, can only occur when a certain combination of material parameters has a distinct value for a given flow condition. A consequent pursuit of this concept will evolve in a quite different aspect of liquid ablation performance. A mechanism for preferential ablation is described and calculated for the simple case where loss by evaporation is large, compared with the loss by flow. The efficiency of liquid ablation can be increased by surface activity. The degree of improvement depends upon the parameter k/Dn and the activity coefficient of the surface-active compound in the liquid glass. The analysis is carried out in the vicinity of the stagnation point of a blunt body for glassy ablation materials. (Author)


Descriptors :   ABLATION , SURFACE PROPERTIES , SURFACE TEMPERATURE , FILMS , SURFACE TENSION , FLUID FLOW , GLASS , STAGNATION POINT


Distribution Statement : APPROVED FOR PUBLIC RELEASE