Browsing by Author "Dahari, Mahidzal"

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Citation Count: Cao, Yan;...et.al. (2022). "Heat transfer improvement between a pair of heater and cooler inside an energy storage by using nano-encapsulated phase change material/water: A numerical modeling", Case Studies in Thermal Engineering, Vol.30.
Heat transfer improvement between a pair of heater and cooler inside an energy storage by using nano-encapsulated phase change material/water: A numerical modeling
(2022) Cao, Yan; Farouk, Naeim; Ayed, Hamdi; Aly, Ayman A.; Jarad, Fahd; Dahari, Mahidzal; Wae-hayee, Makatar; Saleh, B.; 234808
In the present study, the natural convection flow of water with Nano-encapsulated phase change material (NPCM) was simulated inside an insulated chamber, which a pair of pipes were considered as a heater and cooler sources with the boundary condition of uniform temperature. The NPCM's core was made of n-nonadecane with melting temperature of 30.44°C. This core has ability to change the liquid-solid phase to transfer heat between the heater and the cooler sources. Current simulation was steady state and was solved by SIMPLE algorithm based on FVM to investigate the effects of Rayleigh number, volume fraction and location of phase change zone on the convective heat transfer coefficient. Observations showed that, phase change of NPCM occurs at low Rayleigh numbers but had no effect on the convective heat transfer coefficient, but it was directly related to the thermal conductivity of mixture. Moreover, adding volume fraction of NPCM 0.02 into water increased the convective heat transfer coefficient by 10.43%, 19.1% and 18.3% compared to pure water for Rayleigh numbers 102,104,and106, respectively.
Citation Count: Cao, Yan...et al. (2021). "MHD natural convection nanofluid flow in a heat exchanger: Effects of Brownian motion and thermophoresis for nanoparticles distribution", Case Studies in Thermal Engineerin, Vol. 28.
MHD natural convection nanofluid flow in a heat exchanger: Effects of Brownian motion and thermophoresis for nanoparticles distribution
(2021) Cao, Yan; Ayed, Hamdi; Jarad, Fahd; Togun, Hussein; Alias, Hajar; Issakhov, Alibek; Dahari, Mahidzal; Wae-hayee, Makatar; El Ouni, M.H.; 234808
The free convection of Cu-water nanofluid is simulated and investigated inside a square heat exchanger chamber in the presence of MHD magnetic field. The Buongiorno model with the effects of Brownian and thermophoresis motion is considered to nanoparticles distribution inside the chamber. The geometry consists of a square chamber with two cylinders on the right and left sides as heater and cooler in order to create the buoyancy force, respectively. These cylinders represent hot and cold pipes, and the walls of the chamber are heat and mass insulation. the FVM with SIMPLE algorithm are used for velocity and pressure coupling. In current two-phase simulation, the effects of Rayleigh number, Hartmann number, inclination angle of chamber and volume fraction on streamline contours, isothermal lines, Lorentz force lines, nanoparticle distribution and Nusselt number are investigated. By modeling the motion of nanoparticles and evaluating it, a nanoparticle transport zone was observed. The diffusion effects of thermophoresis were significant in this zone. The nanoparticles were thrown from the hot cylinder to the cold cylinder. The application of a magnetic field enlarged the nanoparticle transport zone. However, increasing the Rayleigh number and decreasing the inclination angle of the enclosure caused the nanoparticles to disperse evenly. © 2021 The Authors