Effects of Elastic Fin and Nano‐Enhanced Magnetic Field on the Multiple Slot Nanojet Cooling of Three Rotating Circular Hot Cylinders

Effective cooling solutions for multiple rotating hot objects are needed as they are encountered in many practical applications, such as in metal processing, electronic cooling and food industry. In the present study, slot jet impingement cooling of three identical rotating cylinders (C1, C2, and C3) is studied during forced convection of hybrid nanofluid under an inclined magnetic field. Finite element method with ALE (arbitrary Lagrangian–Eulerian) is employed as the solution technique. The numerical analysis is done considering various values of non‐dimensional rotational speeds ( between 0 and 1000), magnetic field strength (Hartmann number ‐Ha between 0 and 15), and the elastic fin's tilt ( between 0 and 90). The difference between the stiff and elastic fin cases for each of the cylinders decreases when rotations are applied. At , the highest variation is found to be 14 for cylinder C3. In the rotational scenario at maximum speed compared to the stationary one, the average Nusselt number (Nu) increases with greater speeds, while cooling performance enhancement factors become 5.3, 3.8, and 2.9 for cylinders C1, C2, and C3. At the highest rotational speed, impacts of using magnetic field and elastic fin tilt becomes less effective. A higher elastic fin tilt for cylinder C1 leads to improved thermal performance, whereas an average Nu increment of is obtained in the stationary case. With corresponding performance improvements of 16.8, 24.4, and 21, respectively, the cylinders C1, C2, and C3 in the stationary scenario display the greatest thermal performances for the operating points at (nanofluid‐NF, no‐fin, Ha = 0), (NF, with‐fin, Ha = 0), and (NF, with‐fin, Ha = 0). For the same operating points, the best cooling solutions are obtained at , where the cooling performance enhancement values are 12.2, 41.5, and 12.9, respectively.