scholarly journals Heat transfer enhancement through PCM thermal storage by use of copper fins

2016 ◽  
Vol 20 (suppl. 1) ◽  
pp. 251-259 ◽  
Author(s):  
Nedzad Rudonja ◽  
Mirko Komatina ◽  
Goran Zivkovic ◽  
Dragi Antonijevic
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Thermal Storage ◽  
Variable Number ◽  
Melting Time ◽  
Transfer Enhancement ◽  
Enhancement Of Heat Transfer ◽  
C Language ◽  
Fluent Software ◽  
Physical Features

Enhancement of heat transfer over a cylinder shaped thermal energy storage filled by paraffin E53 by use of radial rectangular copper fins was analyzed. The thermo-physical features of the storage material are determined in separate experiments and implemented to Fluent software over UDF. Advanced thermal storage geometry comprehension and optimization required introduction of a parameter suitable for the analysis of heat transfer enhancement, so the ratio of heat transfer surfaces as a factor was proposed and applied. It is revealed that increase of the ratio of heat transfer surfaces leads to the decrease of melting time and vice versa. Numerical analysis, employing the 3D model built in Ansys software, observed storage reservoir geometries with variable number of longitudinal radial fins. The adjusted set of boundary conditions was carried out and both written in C language and implemented over UDF in order to define variable heat flux along the height of the heater. The comparison of acquired numerical and experimental results showed a strong correlation. Experimental validation of numerical results was done on the real TES apparatus.

Numerical Analysis of Heat Transfer Enhancement in a Micro-Channel Due to Mechanical Stirrers

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
M. Sreejith ◽  
S. Chetan ◽  
S. N. Khaderi
Keyword(s):  
Heat Transfer ◽  
Reynolds Number ◽  
Heat Transfer Enhancement ◽  
Peclet Number ◽  
Periodic Case ◽  
Two Dimensional ◽  
Transfer Enhancement ◽  
Fluidic Channel ◽  
Enhancement Of Heat Transfer ◽  
Péclet Number

Abstract Using two-dimensional numerical simulations of the momentum, mass, and energy conservation equations, we investigate the enhancement of heat transfer in a rectangular micro-fluidic channel. The fluid inside the channel is assumed to be stationary initially and actuated by the motion imparted by mechanical stirrers, which are attached to the bottom of the channel. Based on the direction of the oscillation of the stirrers, the boundary conditions can be classified as either no-slip (when the oscillation is perpendicular to the length of the channel) or periodic (when the oscillation is along the length of the channel). The heat transfer enhancement due to the motion of the stirrers (with respect to the stationary stirrer situation) is analyzed in terms of the Reynolds number (ranging from 0.7 to 1000) and the Peclet number (ranging from 10 to 100). We find that the heat transfer first increases and then decreases with an increase in the Reynolds number for any given Peclet number. The heat transferred is maximum at a Reynolds number of 20 for the no-slip case and at a Reynolds number of 40 for the periodic case. For a given Peclet and Reynolds number, the heat flux for the periodic case is always larger than the no-slip case. We explain the reason for these trends using time-averaged flow velocity profiles induced by the oscillation of the mechanical stirrers.

scholarly journals A Numerical Research of Heat Transfer in Rectangular Fins with Different Perforations

2019 ◽  
Vol 8 (12S) ◽  
pp. 367-371
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Buoyancy Force ◽  
Temperature Drop ◽  
Density Variation ◽  
Transfer Enhancement ◽  
Enhancement Of Heat Transfer ◽  
Numerical Research

Heat Transfer enhancement needs buoyancy force. This is to be achieved by making perforations on fin surfaces. The present paper is a study on the enhancement of heat transfer in terms of density, velocity and temperature with three different perforation geometry (parallel square, inclined square and circular). CFD was used to carry out the study of density variation, velocity and temperature drop among different perforated fins. This type of perforated fin has an improvement in heat transfer rate over its dimensionally equivalent solid fin.

Enhancement of Natural Convection by Impingement of Corona Wind

2014 ◽  
Vol 598 ◽  
pp. 271-275
Author(s):  
P. Bhalerao ◽  
F.C. Lai
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Imaging System ◽  
Copper Plate ◽  
Transfer Enhancement ◽  
Enhancement Of Heat Transfer ◽  
Air Jet ◽  
Thermal Imaging System ◽  
Huge Variation ◽  
Corona Wind

The enhancement of heat transfer by corona wind reported in the literature has ranged from 16% to 2500%. It is suspected that such a huge variation has to do with the measurement of temperatures involved. The objective of the present study is to reevaluate the heat transfer enhancement by such technique. To accurately assess the heat transfer enhancement, a thermal imaging system has been used for temperature measurement. A corona wind generator is used to produce air jet directly impinging the heat transfer surface (which is a grounded copper plate of 10 cm by 10 cm uniformly heated by a thermofoil heater). The applied voltage varies from 8 kV to 12 kV with two gap distances of 3 cm and 4 cm between the electrodes.

Experimental Investigations on Heat Transfer Enhancement in a Horizontal Tube Using Converging and Diverging Conical Strip Inserts

2014 ◽  
Vol 592-594 ◽  
pp. 1590-1595 ◽  
Author(s):  
Naga Sarada Somanchi ◽  
Sri Rama R. Devi ◽  
Ravi Gugulothu
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Pressure Drop ◽  
Turbulent Flow ◽  
Heat Transfer Enhancement ◽  
Friction Factor ◽  
Working Fluid ◽  
Experimental Investigations ◽  
Transfer Enhancement ◽  
Enhancement Of Heat Transfer

The present work deals with the results of the experimental investigations carried out on augmentation of turbulent flow heat transfer in a horizontal circular tube by means of tube inserts, with air as working fluid. Experiments were carried out initially for the plain tube (without tube inserts). The Nusselt number and friction factor obtained experimentally were validated against those obtained from theoretical correlations. Secondly experimental investigations using three kinds of tube inserts namely Rectangular bar with diverging conical strips, Rectangular bar with converging conical strips, Rectangular bar with alternate converging diverging conical strips were carried out to estimate the enhancement of heat transfer rate for air in the presence of inserts. The Reynolds number ranged from 8000 to 19000. In the presence of inserts, Nusselt number and pressure drop increased, overall enhancement ratio is calculated to determine the optimum geometry of the tube insert. Based on experimental investigations, it is observed that, the enhancement of heat transfer using Rectangular bar with converging and diverging conical strips is more effective compared to other inserts. Key words: Heat transfer, enhancement, turbulent flow, conical strip inserts, friction factor, pressure drop.

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