Due to its intensive use in engineering applications such as nuclear reactors, jet propulsion, electric power, electronics, air-conditioning and refrigeration, boiling heat transfer has been intensively studied in the past and it is still the subject of ongoing research activities as reported in the open literatures. With the growing interest due to their high thermal performance and the demand for highly efficient small-scale heat transfer devices, more systematic researches are needed to fully understand the mechanisms associated with the boiling heat transfer process in thermal systems. Congruently, the necessity of improving the performance of thermal devices that operate at high heat fluxes under lower wall superheats and to predict the limits of the boiling process is growing and makes the scientific investigation of boiling phenomena inevitable. This objective is achieved in this work by using Computational Fluid Dynamics (CFD) simulation method in place of experimental study method being that by adopting the CFD simulation method, the challenges encountered by various researchers in the areas of equipment cost and time involved in carrying out such experiments would be alleviated as the CFD method allows heat transfer and fluid flow simulation in the early stages of design process which ultimately reduces the development cycle while improving thermal systems performance and cutting costs. This study presents numerical investigation results of heat flux effect on bubble growth and departure during nucleate pool boiling heat transfer of water. The simulation was performed for five different heated surfaces such as: brass, copper, mild steel, stainless steel and aluminium using ANSYS simulation software at atmospheric pressure. The samples were heated in a domain developed for bubble growth during nucleate boiling process under the same operational condition of applied heat flux ranged from 100 to 1000 kW/m^2^ and their corresponding heat transfer coefficient was obtained numerically. Obtained experimental data of other authors from the open literature result is in close agreement with the simulated data, thus confirming the validity of the CFD simulation method used in this study. It is found that the bubble diameter and heat transfer coefficient increase with increasing heat flux. The results revealed that in comparison to other materials tested, better heat transfer performance up to 38.5% and 7.11% is observed for aluminium and brass at lower superheated temperature difference conditions of 6.96K and 14.01 K respectively. This behaviour indicates better bubble development and detachment capability of these heating surface materials and could be used in improving the performance of thermal devices toward producing compact and miniaturized equipment.


Effect of Heat Flux on Pool Boiling Heat Transfer Enhancement (Numerical Investigation Approach)

Division / Sponsors: 
Aerospace, Bioengineering, Applied Mechanics, Design Engineering Division, Advanced Energy Systems, Manufacturing Engineering Division, Noise Control and Acoustics, Nondestructive Evaluation, Diagnosis, and Prognosis (NDPD), Nuclear Engineering Division, Process Industries Division, Fluids Engineering, Heat Transfer, Materials, Microelectromechanical Systems, Safety Engineering and Risk Analysis, Computers & Information in Engineering


Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2020/volume/84478

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