scholarly journals Discussion: “The Effect of Surface Roughness on the Convection Heat-Transfer Coefficient for Fully Developed Turbulent Flow in Ducts With Uniform Heat Flux” (Lancet, R. T., 1959, ASME J. Heat Transfer, 81, pp. 168–173)

1959 ◽  
Vol 81 (2) ◽  
pp. 173
Author(s):  
Myron Tribus
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Surface Roughness ◽  
Heat Transfer Coefficient ◽  
Convection Heat Transfer ◽  
Uniform Heat Flux ◽  
Convection Heat ◽  
Convection Heat Transfer Coefficient ◽  
Fully Developed Turbulent Flow ◽  
Effect Of Surface

The Effect of Surface Roughness on the Convection Heat-Transfer Coefficient for Fully Developed Turbulent Flow in Ducts With Uniform Heat Flux

1959 ◽  
Vol 81 (2) ◽  
pp. 168-173 ◽  
Author(s):  
R. T. Lancet
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Convection Heat Transfer ◽  
Uniform Heat Flux ◽  
Friction Factors ◽  
Fully Developed Turbulent Flow ◽  
The Heat Transfer Coefficient ◽  
Effect Of Surface

Experimental data are presented for the heat-transfer coefficient and friction factor in a smooth and a rough duct with a hydraulic diameter of approximately 0.035 in. The flow was fully developed and turbulent, and the heat addition was uniform over the length of the tube. The rough tube indicated appreciable increases in heat-transfer coefficient and friction factor. The smooth-tube friction factors corresponded to rough-tube values, indicating the difficulty involved in obtaining smooth surfaces for very small ducts.

Experimental Study of Local Heat Transfer Coefficient of R113 Flow Boiling in Vertical Square Tube

2011 ◽  
Vol 374-377 ◽  
pp. 622-625
Author(s):  
Wei Sun ◽  
Ya Jun Guo ◽  
Qin Cheng Bi ◽  
Bin Gao ◽  
Ying Kun Xu
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Flow Boiling ◽  
Convection Heat Transfer ◽  
Equivalent Diameter ◽  
Convection Heat ◽  
Convection Heat Transfer Coefficient ◽  
Steam Quality

This article is based on the experimental investigations on flow boiling heat transfer of R113 with the equivalent diameter of the square tube 15.66mm, mass flow rate 500 ~ 2000kg / (m2•s), steam quality from 0.1 to 1, heat flux 50 ~ 90kW/m2, and pressure 100 ~ 250 kPa. The experimental results show that with the rise of heat flux and mass velocity the local convection heat transfer coefficient increases, and with the enhancement of steam quality the local convection heat transfer coefficient increases firstly and then decreases. By comparison of the experimental data and the calculation results of predecessor’s correlations, a correction coefficient applicable to this experiment was obtained.

The Optimization of Operation Characteristics for Finned Heat Pipe Radiator in Concentrating Photovoltaic System

2011 ◽  
Vol 383-390 ◽  
pp. 6561-6567
Author(s):  
Zi Long Wang ◽  
Hua Zhang ◽  
Hai Tao Zhang
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Solar Cell ◽  
Heat Pipe ◽  
Convection Heat Transfer ◽  
Total Heat ◽  
Side Length ◽  
Convection Heat ◽  
Convection Heat Transfer Coefficient

Aiming at the problem of the concentrating solar cell efficiency restricted by the temperature. The closed two-phase thermosyphon could be used for heat dissipation in concentrat- ing solar cell with high heat flux, then water was selected as the working fluid. Numerical computation methods were adopted to study heat transfer performance of the finned heat pipe radiator in free convection. The temperature field, velocity field, total heat dissipating capacity of different fin pitch and side length as well as free convection heat transfer coefficient under the condition of constant temperature of parent tube were obtained. As a result, the fin side length had greater impact on the natural convection heat transfer coefficient and average total heat flux per unit area; the fin pitch had greater impact on the finned heat pipe radiator total heat dissipating capacity per unit length; the finned heat pipe radiator was the best when fin pitch was 3mm and fin side length was 90mm.

Inverse Heat Transfer Analysis of Grinding, Part 2: Applications

1996 ◽  
Vol 118 (1) ◽  
pp. 143-149 ◽  
Author(s):  
C. Guo ◽  
S. Malkin
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Convection Heat Transfer ◽  
Contact Length ◽  
Heat Transfer Analysis ◽  
Convection Heat ◽  
Convection Heat Transfer Coefficient ◽  
Inverse Heat Transfer

Distributions of the heat flux to the workpiece and the convection heat transfer coefficient on the workpiece surface during straight surface grinding are estimated from measured temperatures in the workpiece subsurface using inverse heat transfer methods developed in Part 1. The results indicate that the heat flux to the workpiece is distributed approximately linearly (triangular heat source) along the grinding zone with about 70 to 75 percent of the total energy transported as heat to the workpiece for grinding of steels with a conventional aluminum oxide wheel and only about 20 percent with CBN superabrasive wheels. The wheel-workpiece contact length corresponding to the region of positive heat flux to the workpiece is found to be generally close to but slightly longer than the theoretical geometric contact length. The convection heat transfer coefficient for cooling by the applied grinding fluid is greatest just behind the trailing edge of the grinding zone where fluid is directly applied, and negligible ahead of the grinding zone.

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