Solution of heat-conduction problem with variable heat-exchange coefficient

1970 ◽  
Vol 18 (1) ◽  
pp. 100-104 ◽  
Author(s):  
V. N. Kozlov
Keyword(s):  
Heat Conduction ◽  
Heat Exchange ◽  
Heat Conduction Problem ◽  
Exchange Coefficient ◽  
Heat Exchange Coefficient ◽  
Variable Heat

scholarly journals On the Heat Exchange Between Rivers and Atmosphere

1982 ◽  
Vol 13 (2) ◽  
pp. 65-78
Author(s):  
Ole Stang
Keyword(s):  
Heat Exchange ◽  
Empirical Relationship ◽  
Flowing Water ◽  
Exchange Coefficient ◽  
Heat Exchange Coefficient ◽  
Hydro Power ◽  
Temperature Changes ◽  
Air Temperatures ◽  
The One ◽  
Semi Empirical

In order to be able to predict water temperatures in rivers which are to be harnessed for hydro power, it is essential to take into account the heat exchange with the atmosphere. It is often sufficient to predict average temperatures and temperature changes for periods of some days. A simple model for the heat exchange between flowing water and atmosphere has been developed for this purpose. The model offers a semi-empirical relationship between air temperature and water temperature. In this paper the model is applied to the Orkla river in Central Norway, and it is demonstrated how analyses of diurnal variations of water and air temperatures make it possible to predict the downstream decay of temperature changes originating from man-made releases. As a result an average heat exchange coefficient is calculated for Orkla for the summer of 1980. This calculation indicates that the cooling/heating rate in the flowing water in Orkla is considerably greater than the one for lakes under the same meteorological conditions.

Temperature State of the Anisotropic Spherical Layer During Convective Heat Exchange with the Environment

2019 ◽  
pp. 40-55
Author(s):  
V.S. Zarubin ◽  
V.V. Leonov ◽  
V.S. Jr. Zarubin
Keyword(s):  
Heat Conduction ◽  
Heat Exchange ◽  
Convective Heat ◽  
Outer Surface ◽  
Heat Conduction Problem ◽  
Convective Heat Exchange ◽  
Spherical Layer ◽  
Coating Material ◽  
Temperature State ◽  
Heat Shielding

The paper focuses on the process of steady heat conduction in a spherical layer of a heat-shielding coating made of anisotropic material. The inner surface of the layer is ideally heat-insulated but its outer surface is exposed to heating by convective heat exchange with the environment, the temperature of which varies along this surface. Based on the obtained solution of the linear heat conduction problem, we quantitatively assessed the influence of the degree of anisotropy of the coating material, its relative thickness, intensity of convective heat transfer, and uneven distribution of ambient temperature on the equalization of temperature distribution in the spherical layer. The results obtained can be used to select the characteristics of an anisotropic coating material in order to reduce the temperature of the outer surface of the spherical layer in the zone of the most intense heating.

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