Search for: boiling-heat-transfer-coefficients
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    Pool boiling heat transfer enhancement by twisted-tape fins

    , Article Applied Thermal Engineering ; Volume 135 , 2018 , Pages 170-177 ; 13594311 (ISSN) Ebrahimi Dehshali, M ; Najm Barzanji, Z ; Hakkaki Fard, A ; Sharif University of Technology
    Elsevier Ltd  2018
    The boiling phenomena in a quiescent fluid is the nucleate pool boiling which has attracted much interest in the thermal management studies. This paper investigates the effect of the installed Twisted Tape Fins (TTFs) on the heat transfer from a surface with a temperature above the water saturation point to a coil condenser. Four different arrangements of TTFs (1, 3, 5, and 9 TTFs) are fabricated and their boiling performance in distilled water at atmospheric pressure is experimentally tested. It was observed that the increase in the boiling heat transfer coefficient of the plate with nine TTFs compared to that of the plain one is 15.5%. Furthermore, the effect of TTFs heights on the heat... 

    Enhancement of pool boiling heat transfer using ferromagnetic beads in a variable magnetic field

    , Article Applied Thermal Engineering ; Volume 164 , 2020 Rahmati, P ; Ebrahimi Dehshali, M ; Hakkaki Fard, A ; Sharif University of Technology
    Elsevier Ltd  2020
    The pool boiling is one of the heat transfer mechanisms used in cooling systems. Using an external force to improve the efficiency of thermo-fluid systems is among the most effective approaches, and also highly applicable in enhancing heat transfer. In this study, the pool boiling of water, as the working fluid, in the presence of a variable magnetic field, is studied. To this end, ferromagnetic beads were placed on the boiling surface, and the effect of their movements due to a variable magnetic field was observed and measured. The number of beads was selected such that they would cover 1/3, 1/2 and 2/3 of the surface in different cases and the magnetic field was controlled by altering... 

    Experimental investigation of the effect of copper electrodeposition on the aluminum surface and addition of ethylene glycol on boiling heat transfer coefficient

    , Article Heat and Mass Transfer/Waerme- und Stoffuebertragung ; 2021 ; 09477411 (ISSN) Azadi Milani, P ; Mahdi, M ; Abarghooei, A ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    In this research, the effect of surface characteristics on boiling heat transfer has been investigated experimentally. For this purpose, a device with the ability to automatically record the liquid temperature of the inlet and outlet of the test area, calculate the coefficient of boiling heat transfer, and heat flux has been developed. The automatic temperature stability of the working fluid and the ability to investigate the effect of surfaces with different characteristics (in terms of material and surface structure) on the boiling heat transfer parameters are the most important features of this device. The performance of the experimental setup was evaluated by the modified "Chen" equation... 

    Pool boiling heat transfer in dilute water/triethyleneglycol solutions

    , Article Chinese Journal of Chemical Engineering ; Volume 17, Issue 4 , 2009 , Pages 552-561 ; 10049541 (ISSN) Alavi Fazel, S. A ; Safekordi, A. A ; Jamialahmadi, M ; Sharif University of Technology
    Boiling of water/triethyleneglycol (TEG) binary solution has a wide-ranging application in the gas processing engineering. Design, operation and optimization of the involved boilers require accurate prediction of boiling heat transfer coefficient between surface and solution. In this investigation, nucleate pool boiling heat transfer coefficient has been experimentally measured on a horizontal rod heater in water/TEG binary solutions in a wide range of concentrations and heat fluxes under ambient condition. The present experimental data are correlated using major existing correlations. In addition a correlation is presented for prediction of pool boiling heat transfer for the system in which... 

    Visualization of pool boiling heat transfer of magnetic nanofluid

    , Article Heat Transfer - Asian Research ; Volume 48, Issue 7 , 2019 , Pages 2700-2713 ; 10992871 (ISSN) Zarei Saleh Abad, M ; Ebrahimi Dehshali, M ; Bijarchi, M. A ; Shafii, M. B ; Moosavi, A ; Sharif University of Technology
    John Wiley and Sons Inc  2019
    To increase heat transfer, ferrofluids have been utilized to study the effective parameters of pool boiling. Changes and possible enhancement of pool boiling heat transfer of magnetic fluids is a function of magnetic field and concentration of nanoparticles. To the best knowledge of the authors, no systematic experiments have been conducted to visualize the phenomena during the boiling of ferrofluids with different concentrations. In this study an experimental investigation has been conducted, by designing and fabricating a novel hele-shaw vessel with glass sides, to explore via visualizations some details in the pool boiling of ferrofluids. Boiling patterns of ferrofluids at various...