Browsing by Author "Gasmi H."

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    Application and CFD-Based Optimization of a Novel Porous Object for Confined Slot Jet Impingement Cooling Systems under a Magnetic Field
    (MDPI, 2022) Aich W.; Selimefendigil F.; Ayadi B.; Ben Said L.; Alshammari B.M.; Kolsi L.; Betrouni S.A.; Gasmi H.
    A novel porous object for the control of the convective heat transfer of confined slot nanojet impingement is offered under magnetic field effects, while optimization-assisted computational fluid dynamics is used to find the best working conditions to achieve the best performance of the system. The flow, thermal patterns, and heat transfer characteristics were influenced by the variation in rotational Reynolds number (Rew), Hartmann number (Ha), permeability of the porous object (Da) and its location (Mx). There was a 14.5% difference in the average Nusselt number (Nu) at the highest Rew when motionless object configuration at Ha = 5 was compared, while it was less than 2% at Ha = 25. At Rew = −600, the average Nu variation was 22% when cases with the lowest and highest magnetic field strength were compared. The porous object provides an excellent tool for convective heat transfer control, while the best performance was achieved by using optimization-assisted computational fluid dynamics. The optimal sets of (Rew, Da, Mx, AR) for porous object were (−315.97, 0.0188, −1.456, 0.235), (−181.167, 0.0167, −1.441, 0.2), and (−483.13, 0.0210, −0.348, 0.2) at Ha = 5, 10, and 25, respectively. At the optimal operating point, the local Nu enhancements were 19.46%, 44.86%, and −0.54% at Ha = 5, 10, and 15, respectively, when the no-object case was compared, while the average values were 7.87%, 8.09% and 5.04%. © 2022 by the authors.
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    Conjugate Heat Transfer Analysis for Cooling of a Conductive Panel by Combined Utilization of Nanoimpinging Jets and Double Rotating Cylinders
    (MDPI, 2023) Kolsi L.; Selimefendigil F.; Gasmi H.; Alshammari B.M.
    In this work, double rotating active cylinders and slot nanojet impingement are considered for the cooling system of a conductive panel. Colder surface temperatures of the cylinders are used, while different rotational speeds are assigned for each of the cylinders. The impacts of cylinder rotational speeds, size and distance between them on the cooling performance are evaluated. The rotational effects and size of the cylinders are found to be very effective on the overall thermal performance. At the highest rotational speeds of the cylinders, the average Nusselt number (Nu) rises by about 30.8%, while the panel temperature drops by about 5.84 (Formula presented.) C. When increasing the cylinder sizes, temperature drops become 7 (Formula presented.) C, while they are only 1.75 (Formula presented.) C when varying the distance between the cylinders. Subcooling and nanofluid utilization contributes positively to the cooling performance, while 1.25 (Formula presented.) C and 10 (Formula presented.) C temperature drops are found by varying the subcooled temperature and solid volume fraction. An artificial neural network is used for the estimation of maximum and average panel temperatures when double cylinder parameters are used as the input. © 2023 by the authors.