EFFECT OF FREE-STREAM TURBULENCE ON THE HEAT TRANSFER IN THE TURBULENT BOUNDARY LAYER

1978 ◽  
Author(s):  
Anupras Slanciauskas ◽  
Antanas Pedisius
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Free Stream ◽  
Free Stream Turbulence

Influence of Free-Stream Turbulence on Turbulent Boundary Layer Heat Transfer and Mean Profile Development, Part I—Experimental Data

1983 ◽  
Vol 105 (1) ◽  
pp. 33-40 ◽  
Author(s):  
M. F. Blair
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Boundary Layer Flow ◽  
Free Stream ◽  
Full Range ◽  
Stream Velocity ◽  
Free Stream Turbulence ◽  
Turbulent Boundary Layer Flow ◽  
Layer Flow

An experimental research program was conducted to determine the influence of free-stream turbulence on zero pressure gradient, fully turbulent boundary layer flow. Connective heat transfer coefficients and boundary layer mean velocity and temperature profile data were obtained for a constant free-stream velocity of 30 m/s and free-stream turbulence intensities ranging from approximately 1/4 to 7 percent. Free-stream multicomponent turbulence intensity, longitudinal integral scale, and spectral distributions were obtained for the full range of turbulence levels. The test results with 1/4 percent free-stream turbulence indicate that these data were in excellent agreement with classic two-dimensional, low free-stream turbulence, turbulent boundary layer correlations. For fully turbulent boundary layer flow, both the skin friction and heat transfer were found to be substantially increased (up to ∼ 20 percent) for the higher levels of free-stream turbulence. Detailed results of the experimental study are presented in the present paper (Part I). A comprehensive analysis is provided in a companion paper (Part II).

Influence of Free-Stream Turbulence on Turbulent Boundary Layer Heat Transfer and Mean Profile Development, Part II—Analysis of Results

1983 ◽  
Vol 105 (1) ◽  
pp. 41-47 ◽  
Author(s):  
M. F. Blair
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Skin Friction ◽  
Free Stream ◽  
Distribution Data ◽  
Stream Velocity ◽  
Mean Velocity ◽  
Reynolds Analogy ◽  
Free Stream Turbulence

An experimental research program was conducted to determine the influence of free-stream turbulence on zero pressure gradient, fully turbulent boundary layer flow. In Part I of this paper, convective heat transfer coefficients, boundary layer mean velocity and temperature profile data, as well as wall skin friction coefficient distribution data were presented for five flow conditions of constant free-stream velocity (30 m/s) and free-stream turbulence intensities ranging from approximately 1/4 to 7 percent. These data indicated that the turbulence had significant effects on both the turbulent boundary layer skin friction and heat transfer. In the current paper, these new data are compared to various independent experimental data and analytical correlations of free-stream turbulence effects. This analysis has shown that the effects documented in Part I were a function of the freestream turbulence intensity, the turbulence length scale, and the boundary layer momentum thickness Reynolds number. In addition, the Reynolds analogy factor (2St/cf) was shown to increase by just over 1 percent for each 1 percent increase in free-stream turbulence level. New correlations for the influence of free-stream turbulence on skin friction, heat transfer, and the Reynolds analogy factor are presented.

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