Accession Number : AD0678602

Title :   EXPERIMENTAL STUDY OF PSEUDO TRANSPIRATION AT AN ORIFICE IN RAREFIED FLOW.

Descriptive Note : Technical rept.,

Corporate Author : CORNELL AERONAUTICAL LAB INC BUFFALO N Y AERODYNAMIC RESEARCH DEPT

Personal Author(s) : Bartz,John A. ; Vidal,Robert J.

Report Date : SEP 1968

Pagination or Media Count : 22

Abstract : An experimental investigation of the low-density orifice effect, which occurs on a body that is not in thermal equilibrium with the ambient flow, was performed with a sharp flat plate under hypersonic, rarefied flow conditions. The surface pressure, measured directly with pressure transducers mounted flush with the model surface, was as much as three times larger than the pressure measured with similar transducers mounted in a cavity and vented to the surface through an orifice. The physical origin of the effect is described and an existing semi-empirical method for predicting this effect is reviewed. This method is tested with the data to assess its accuracy, and it is found to underestimate the effect by about 20% plus or minus 20%. It appears that this discrepancy might stem from a temperature effect not included in the method. (Author)

Descriptors :   (*MASS TRANSFER, ORIFICES), (*RAREFIED GAS DYNAMICS, MASS TRANSFER), HYPERSONIC CHARACTERISTICS, FLAT PLATE MODELS, PRESSURE, SURFACE PROPERTIES

Subject Categories : Aerodynamics
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE