Analyzing thermal performance and entropy generation in time-dependent buoyancy flow of water-based over rotating sphere with ternary nanoparticle shape factor

Abstract The heat transfer augmentation, solar power systems, medical equipment, semiconductor cooling, aerospace, and automotive industries all use ternary hybrid nanofluids (THNFs). The current study is mainly about a magnetized THNF flow that cannot be squished around a spinning sphere that has different viscosity, thermal conductivity, and shape (brick, platelets, cylinder, and blade). The heat transport simulation incorporates the principles of viscous dissipation and joule heating. Water is mixed with silver, magnesium oxide, and iron trioxide to make the THNF. Similarity substitution converts model equations to ordinary differential equations (ODEs). Runge–Kutta fourth order numerically estimates the non-dimensional set of ODEs. For certain emergent parameters, velocity, temperature, entropy generation, Nusselt number, and skin friction are computed and analyzed. The research shows that entropy generation increases with brinkman number, nanoparticle volume fraction and magnetic parameters and reduces with temperature difference parameter. Increasing the unsteadiness parameter upsurges velocity in the x-direction, but decreases it in the z-direction and temperature curve. Skin friction upsurges in the x-direction and declines in the z-direction with rotation. Platelet-shaped nanoparticles usually outperform blade, brick, and cylinder shapes. When mass suction $( S )$ is elevated from 1.0 to 2.0, the heat transfer rate increases by 47.25% for the brick form, 47.26% for the platelets shape, 35.08% for the cylinders shape, and 37.65% for the blades shape. Comparing the results to prior literature shows excellent agreement.