Browsing by Author "Issakhov, Alibek"

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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