scholarly journals REDUCTION OF LOCAL HEATING IN TANKS OF POWERFUL TRANSFORMERS BY HEAT-REMOVING LOCAL RADIATORS WITH RIBBED

2021 ◽  
Vol 2021 (58) ◽  
pp. 82-89
Author(s):  
V.F. Ivankov ◽  
◽  
А.V. Basova ◽  
І.V. Khimjk ◽  
◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Modeling ◽  
Local Heating ◽  
Convection Heat Transfer ◽  
Copper Plate ◽  
Conductive Heat ◽  
Thermal Coupling ◽  
Convection Heat ◽  
Practical Application ◽  
Flat Base

The main approaches, the results of numerical modeling, and examples of the practical application of heat-dissipating radiators made of aluminum, with a flat base, and with ribbing to reduce local heating in ferromagnetic covers and walls of transformer tanks, which arise in cases of concentration of magnetic fluxes from multi-ampere taps or magnetic shunts are presented. The case of thermal coupling of a non-magnetic flange of a yoke beam with a flat base of a radiator (copper plate) is considered, which shows the possibility of reducing local heating of the beam using conductive heat transfer between the shelf and the plate and convection heat transfer from their surfaces to cooling oil. References 4, figures 7.

Numerical Simulation of Convection Heat Transfer in a Plate Channel with Sintered Copper Porous Ribs

2012 ◽  
Vol 605-607 ◽  
pp. 1350-1355
Author(s):  
Xin Wei Lu ◽  
De Zhi Yang ◽  
Wen Jiong Cao ◽  
Zhao Yao Zhou
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Reynolds Number ◽  
Porous Media ◽  
Convection Heat Transfer ◽  
Copper Plate ◽  
Local Thermal Equilibrium ◽  
Convection Heat ◽  
Sintered Copper ◽  
Plate Channel

Convection heat transfer in a plate channel periodically fitted with sintered copper porous ribs attached to a copper plate was numerically studied. The local thermal equilibrium model was adopted in the energy equation to evaluate the temperature of fluid and solid. The effect of porosity, Reynolds number and heat flux applied to the copper plate on the heat transfer characteristic of the porous media was investigated respectively. The numerical results show that the heat transfer can be enhanced by increasing Reynolds number, decreasing the porosity and the heat transfer enhancement of the porous media took effect significantly when subjected to high heat flux. Detailed development of the porous media temperature field and the Nusselt number of the wall as a function of Reynolds number for different porosity and heat flux were also presented.

Natural Convection and Sidewall Losses in Trapezoidal Groove Collectors

1981 ◽  
Vol 103 (2) ◽  
pp. 167-172
Author(s):  
L. Iyican ◽  
L. C. Witte ◽  
Y. Bayazitoglu
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Natural Convection ◽  
Convection Heat Transfer ◽  
Heat Losses ◽  
Natural Convection Heat Transfer ◽  
Conductive Heat ◽  
Convection Heat ◽  
Uniform Temperature ◽  
Number Range

Experimental data for heat transfer across air-filled inclined trapezoidal enclosures are reported for a Rayleigh number range of ∼2 × 103 to ∼5 × 107. The large side was cooled to uniform temperature while the opposing small side was electrically heated. The enclosures were completed by two aluminum sidewalls which simulated the reflective surfaces in moderately-concentrating solar collectors. The experiments show that conductive heat losses up the sidewalls can be very large even when the sidewalls are thermally insulated from the top and bottom surfaces. However, the conductivity of the sidewalls has only a small effect on convective heat transfer across the groove. Natural convection heat transfer in the groove can be correlated reasonably well by an equation of the form Nu = C Ra0.345.

scholarly journals Numerical Modeling of Non-Similar Mixed Convection Heat Transfer over a Stretching Surface with Slip Conditions

2015 ◽  
Vol 05 (06) ◽  
pp. 117-128 ◽  
Author(s):  
A. Subba Rao ◽  
V. R. Prasad ◽  
N. Nagendra ◽  
K. V. N. Murthy ◽  
N. Bhaskar Reddy ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Modeling ◽  
Mixed Convection ◽  
Convection Heat Transfer ◽  
Convection Heat ◽  
Stretching Surface ◽  
Slip Conditions ◽  
Mixed Convection Heat Transfer

Numerical Simulation of Natural Convection Heat Transfer of Nanofluid With Cu, MWCNT, and Al2O3 Nanoparticles in a Cavity With Different Aspect Ratios

2019 ◽  
Vol 11 (6) ◽  
Author(s):  
Hossein Goodarzi ◽  
Omid Ali Akbari ◽  
Mohammad Mohsen Sarafraz ◽  
Majid Mokhtari Karchegani ◽  
Mohammad Reza Safaei ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Natural Convection ◽  
Convection Heat Transfer ◽  
Al2o3 Nanoparticles ◽  
Natural Convection Heat Transfer ◽  
Conductive Heat ◽  
Convection Heat ◽  
Closed Cavity ◽  
Aspect Ratios ◽  
Hot Zone

Effect of the size of a closed cavity and different nanoparticles on natural convection heat transfer is investigated using the finite volume method. In the current numerical study, free convection of nanofluid with Cu, multi-walled carbon nanotubes, and Al2O3 nanoparticles is considered at Rayleigh numbers (Ra) of 10–100,000 inside a two-dimensional rectangular cavity with different aspect ratios. Results of this study show that in the presence of cooling fluid with low temperature and hot zone in the cavity, due to the temperature difference between the fluid and hot zone, heat transfer occurs. Heat transfer in the cavity is influenced by fluid circulation caused by natural convection heat transfer and conductive heat transfer mechanism.

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