Browsing by Author "Wae-hayee, Makatar"

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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). "Inducing swirl flow inside the pipes of flat-plate solar collector by using multiple nozzles for enhancing thermal performance", Renewable Energy, Vol. 180, pp. 1344-1357.
Inducing swirl flow inside the pipes of flat-plate solar collector by using multiple nozzles for enhancing thermal performance
(2021) Cao, Yan; Ayed, Hamdi; Hashemian, Mehran; Issakhov, Alibek; Jarad, Fahd; Wae-hayee, Makatar; 234808
In this numerical study, an attempt has been made to improve the thermal performance of the flat-plate solar collector (FPSC) by inducing the swirl flow inside the tube by the considered nozzles. To this end, the effect of the number of circumferential nozzles and their inclination angles was taken into the account. The considered number of nozzles was "single", ''dual'', ''triple'', and ''quad''. For each of the said cases, the inclination angle of nozzles was taken 30°, 45°, 60°, and 90° (A30, A45, A60, A90). Moreover, the mass flow rate of single-nozzle pipe was considered 0.2 kg/s, 1 kg/s, and 2 kg/s. To analyze all of the cases under identical conditions, the said mass flow rates were distributed equally among all of the nozzles (for ''dual'', ''triple'', and ''quad''). All of the characteristics were defined in a form of "A…-D…-N…-M…'' where ''A…'', "D…", "N…", and “M…” stand for angle of injection, diameter of pipe, nozzle cross-section edge, and mass flow rate, respectively. Numerical simulation (3-dimensional) of the system was performed by Finite Volume Method (FVM). The turbulence nature of flow was simulated by the k-omega SST (shear stress transport) turbulent model. Results showed that the "single-nozzle'' swirl generator had the highest thermal performance factor (TPF) so that for all cases its values were greater than unit. Mass flow rate growth increases Nu, heat extraction rate, and kinetic energy rate (KER) while drops friction factor and outlet temperature. Increment of injection angle increases outlet temperature and friction factor and reduces KER. The maximum and minimum values of TPF are 4.19 and 0.44 which belong to “single; A30-D50-N12.5-M0.2” and "quad; A90-D50-N12.5-M0.5", respectively. © 2021 Elsevier Ltd
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
Citation Count: Li, Min...et al. (2021). "Thermo-economic, exergetic and mechanical analysis of thermoelectric generator with hollow leg structure; impact of leg cross-section shape and hollow-to-filled area ratio", Case Studies in Thermal Engineering, Vol. 27.
Thermo-economic, exergetic and mechanical analysis of thermoelectric generator with hollow leg structure; impact of leg cross-section shape and hollow-to-filled area ratio
(2021) Li, Min; Dizaji, Hamed Sadighi; Asaadi, Soheil; Jarad, Fahd; Anqi, Ali E.; Wae-hayee, Makatar; 234808
Filled square cross-section shape is the common conventional structure for n-type and p-type legs of thermoelectric generators. However, other cross-section shapes with hollow structure can significantly increase the output power of thermoelectric generator. However, mechanical strength and economic considerations may still remain as the significant challenges and factors. Hence, in this research, different hollow cross-section leg shapes are investigated for thermoelectric generator from all thermal, economic, exergetic and mechanical viewpoints simultaneously through a 3D validated numerical simulation. Output voltage/power, energy-efficiency, exergy efficiency, Von-Mises stress, and the dollar/watt value are calculated for all mentioned structures and optimum conditions are identified. As a sample result, the triangular shape leg is able to generate up to 100% more power and better conversion/exergy efficiency (compared to the rectangular) at maximum input heat flux while mechanically less reliable design. Many other remarkable and interesting findings are provided in this manuscript.