Further note on an approximate method for calculating heat transfer in laminar boundary-layers with constant wall temperature

1962 ◽  
Vol 5 (7) ◽  
pp. 697-700 ◽  
Author(s):  
A.G. Smith ◽  
V.L. Shah
Keyword(s):  
Heat Transfer ◽  
Approximate Method ◽  
Boundary Layers ◽  
Wall Temperature ◽  
Constant Wall Temperature ◽  
Laminar Boundary Layers

Heat Transfer Visualization and Measurement in Unstable Concave-Wall Laminar Boundary Layers

1989 ◽  
Vol 111 (1) ◽  
pp. 51-56 ◽  
Author(s):  
R. I. Crane ◽  
J. Sabzvari
Keyword(s):  
Heat Transfer ◽  
Boundary Layers ◽  
Constant Heat Flux ◽  
Contributory Factor ◽  
Constant Wall Temperature ◽  
Pressure Surface ◽  
Laminar Boundary Layers ◽  
Concave Wall ◽  
Temperature Constant ◽  
Intermittency Factor

Using liquid crystal sheet in a hybrid constant-wall-temperature/constant-heat-flux procedure, heat transfer distributions have been measured in concave-wall laminar boundary layers with a natural Gortler vortex system in a near-zero pressure gradient. Stanton numbers at vortex downwash positions across the span exceeded those at upwash positions by factors as high as three. Spanwise-averaged Stanton numbers exceeded analytical flat-plate values only after the appearance of highly inflected upwash velocity profiles and the onset of span wise meandering of the vortices, where the Gortler number exceeded ten. Levels then reached values comparable with turbulent correlations, at Reynolds numbers and turbulence levels (up to 3 percent) where previous measurements of the intermittency factor indicated that transition had not begun. Boundary layer thinning in downwash zones could account for much of the heat transfer enhancement. The phenomenon could be a contributory factor to the long, apparently transitional regions often reported on blade cascade pressure surfaces, although the Gortler numbers where enhancement occurred are higher than those normally associated with pressure-surface transition.

Laminar boundary layers behind detonation waves

1983 ◽  
Vol 387 (1793) ◽  
pp. 331-349 ◽  
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Boundary Layers ◽  
Flow Analysis ◽  
Time Dependent ◽  
Detonation Waves ◽  
Planar Geometry ◽  
Laminar Boundary Layers ◽  
Spherical Detonation ◽  
Layer Flow

New solutions are presented for non-stationary boundary layers induced by planar, cylindrical and spherical Chapman-Jouguet (C-J) detonation waves. The numerical results show that the Prandtl number ( Pr ) has a very significant influence on the boundary-layer-flow structure. A comparison with available time-dependent heat-transfer measurements in a planar geometry in a 2H 2 + O 2 mixture shows much better agreement with the present analysis than has been obtained previously by others. This lends confidence to the new results on boundary layers induced by cylindrical and spherical detonation waves. Only the spherical-flow analysis is given here in detail for brevity.

A Reference Temperature Method for Compressible Laminar Boundary Layers

1973 ◽  
Vol 2 (4) ◽  
pp. 201-204
Author(s):  
R. Camarero
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Wall Temperature ◽  
Reference Temperature ◽  
Integral Approach ◽  
Pressure Gradients ◽  
Two Dimensional ◽  
Laminar Boundary Layers ◽  
Temperature Method ◽  
Compressibility Effects

A calculation procedure for the solution of two-dimensional and axi-symmetric laminar boundary layers in compressible flow has been developed. The method is an extension of the integral approach of Tani to include compressibility effects by means of a reference temperature. Arbitrary pressure gradients and wall temperature can be specified. Comparisons with experiments obtained for supersonic flows over a flat plate indicate that the method yields adequate results. The method is then applied to the solution of the boundary layer on a Basemann inlet.

Total Temperature Measurements of Gaseous Flow at Micro-Tube Outlet

2009 ◽  
Author(s):  
Takaharu Yamamoto ◽  
Chungpyo Hong ◽  
Yutaka Asako ◽  
Koichi Suzuki
Keyword(s):  
Heat Transfer ◽  
Wall Temperature ◽  
Gas Flow ◽  
Atmospheric Condition ◽  
Stagnation Temperature ◽  
Constant Wall Temperature ◽  
Gaseous Flow ◽  
Circulating Water ◽  
Total Temperature ◽  
Exit Mach Number

This paper presents experimental results on heat transfer characteristics of gaseous flow in a micro-tube with constant wall temperature. The experiment was performed for nitrogen gas flow through a micro-tube with 166 micro meters in diameter and 50mm in length. The wall temperature was maintained at 305K, 310K, 330K and 350K by circulating water around the micro-tube, respectively. The stagnation pressure is chosen in such a way that the exit Mach number ranges from 0.1 to 1.0. The outlet pressure was fixed at the atmospheric condition. The total temperature at the outlet, the inlet stagnation temperature, the mass flow rate, and the inlet pressure were measured. The numerical computations based on the Aribitary - Langrangian - Eulerian (ALE) method were also performed for the same cases of the experiment for validation of numerical computation. The both results are in excellent agreement. The total temperatures obtained by the present study are slightly higher than those of the incompressible flow. This is due to the additional heat transfer near the micro-tube outlet caused by the temperature decrease due to the energy conversion into the kinetic energy. A quantitative correlation for the prediction of the heat transfer rate of the gaseous flow in a micro-tube was proposed.

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