scholarly journals Effects of Surface Roughness on Contact Heat Transfer between Contacting Particles

2008 ◽  
Vol 3 ◽  
pp. 83-89
Author(s):  
Kenya KUWAGI ◽  
Muhammad Arif Bin MOKHTAR ◽  
Toshihiro TAKAMI ◽  
Masayuki HORIO
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Contact Heat ◽  
Contact Heat Transfer

Influence of Surface Roughness on Contact Heat Transfer

2010 ◽  
Author(s):  
V. A. Ustinov ◽  
R. Kneer ◽  
F. Al-Sibai ◽  
S. G. Schulz ◽  
E. El-Magd
Keyword(s):  
Heat Transfer ◽  
Surface Roughness ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Contact Area ◽  
Real Contact Area ◽  
Contact Heat ◽  
Real Contact ◽  
Contact Heat Transfer ◽  
Contact Pressures

Almost all technical devices in use today are assemblies of individual pieces. For all force-based assembly methods, such as bolting or press-fitting, the thermal behavior is influenced by the contact resistance at the joint surface. For metal pieces in contact with each other, the authors have developed a measurement method and analysis tools enabling the determination of the contact heat transfer coefficient. Previously published results [1, 2, 3] have shown the dependence of the contact heat transfer coefficient on surface structure, contact pressure and material properties. The present work provides experimental and analytical data for the contact heat transfer coefficient and also proposes a model for calculating the real contact area of two surfaces which are placed under different contact pressures. Experiments were conducted for two material combinations with three different surface structures, while varying the contact pressures from 7 MPa to 230 MPa. When selecting average surface roughness (Rz) as a characterizing parameter for surface structure, the results did not show a consistent trend. Thus, in this paper Rz was replaced by the real contact area between the two surfaces of interest. This area was determined by applying a refined method based on surface roughness measurements. The experimental data show a better consistency, when plotting the contact heat transfer coefficient relative to real contact area (Fk) rather than the previously used Rz–values.

Hydrodynamic Features of Contact Heat-Transfer Packing Devices

1997 ◽  
Vol 28 (4-6) ◽  
pp. 393-397
Author(s):  
N. Yu. Koloskova ◽  
V. V. Dubrovskaya ◽  
V. V. Orlyanskii
Keyword(s):  
Heat Transfer ◽  
Contact Heat ◽  
Contact Heat Transfer

Heat Transfer Model in a Rotary Drum During the Fermentation Process

2020 ◽  
Vol 77 (1) ◽  
pp. 151-160
Author(s):  
Norazaliza Mohd Jamil ◽  
Aainaa Izyan Nafsun ◽  
Abdul Rahman Mohd Kasim
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Heat Transfer Coefficient ◽  
Fermentation Process ◽  
Transfer Model ◽  
Kutta Method ◽  
Contact Heat ◽  
Contact Heat Transfer ◽  
Runge Kutta Method ◽  
Rotary Drum

A new mathematical model describing heat transfer during the fermentation process in a rotary drum is proposed. The model includes representations of the kinetic reactions, the temperature of the solid bed, and physical structures within the rotary drum. The model is developed using five ordinary differential equations and was then solved using the Runge-Kutta method embedded in MATLAB software. A reasonable behaviour for the temperature profile to the fermentation process is achieved. The results show that the mass of the solid bed, contact heat transfer coefficient, and the wall temperature has a significant effect on the fermentation process in a rotary drum.

Development of an Equipment Model in Chlorine Liquefaction Process

2018 ◽  
Vol 769 ◽  
pp. 371-376 ◽  
Author(s):  
Elena Alexandrovna Muravyova ◽  
Alexander Ivanovich Kubryak
Keyword(s):  
Heat Transfer ◽  
Mathematical Model ◽  
Control System ◽  
Central Position ◽  
Contact Heat ◽  
Contact Heat Transfer ◽  
Equipment Unit ◽  
Liquefaction Process ◽  
Further Development ◽  
Heat Carriers

The article describes the development of a mathematical model for a condenser-evaporator, which occupies a central position in chlorine liquefaction process. The model describes the key processes in the equipment unit: freon evaporation, chlorine condensation, change in freon level and in equipment pressure. The model is based on the equations characterizing the processes mentioned above, which makes it possible to use the model for design and calculations of non-contact heat transfer equipment with phase transitions of heat carriers of various characteristics. The simulation was carried out with the aim of further development of a condenser-evaporator control system.

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