Accession Number : AD0669330

Title :   ENHANCEMENT OF HEAT AND MASS TRANSFER IN A STAGNATION REGION BY FREE STREAM VORTICITY,

Corporate Author : BROWN UNIV PROVIDENCE R I

Personal Author(s) : Williams,George

Report Date : FEB 1968

Pagination or Media Count : 118

Abstract : Calculations were performed using a mathematical model to show the effect of free-stream turbulence on stagnation-point heat transfer from circular cylinders in cross-flow. The calculations were performed on an IBM 1130 digital computer for a wavelength equal to 5/3 times the neutral wavelength for the flow. This wavelength was obtained from experimental mass transfer results. The Prandtl numbers used in the computations were 0.70, 2.70, 2.85, 3.00, 7.00 and 100, and the amplitude parameter A had the range 0.0(0.5)3.0. The results of the calculations show that the mean heat transfer at the stagnation point increases with Prandtl number for each value of the amplitude parameter used in the calculations, and that the largest increase occurred for a Prandtl number equal to 100. A method is proposed on how to relate the amplitude parameter A to free-stream turbulence intensity. For a Prandtl number of 2.85, a comparison is made between heat transfer results of the model and experimental mass transfer results. The agreement between results is found to be satisfactory. (Author)

Descriptors :   (*HEAT TRANSFER, STAGNATION POINT), (*MASS TRANSFER, STAGNATION POINT), (*VORTICES, TRANSPORT PROPERTIES), PRANDTL NUMBER, EQUATIONS OF MOTION, VELOCITY, BOUNDARY LAYER, DIGITAL COMPUTERS

Subject Categories : Aerodynamics
      Fluid Mechanics
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE