Exploring the Effects of Inter-Particle Spacing and Nanoparticle Radius in The Flow Over a Rotating Exponentially Stretching Surface and Entropy Generation for Al2O3/H2O Nanofluid

Abstract

Nanofluids have found extensive industrial, engineering, and medical applications due to their increased heat transfer rate. A three-dimensional (3D) incompressible flow on rotating exponentially stretching surfaces was investigated for the water base fluid and aluminum oxide (Al₂O₃) nanoparticle. This study can be considered a novel analysis as it explores the effects of inter-particle spacing and nanoparticle radius on entropy generation, velocity, temperature, skin friction, Nusselt number (Nu), and Bejan number (Be) for an exponentially stretching flow. Partial differential equations (PDEs) are obtained using continuity, momentum, and energy equations. They are converted into three coupled ordinary differential equations (ODEs) by applying appropriate transformations. Numerical results and graphs are obtained using the bvp4c algorithm in MATLAB software. According to the results, the entropy generation rate decreases with increasing inter-particle spacing and increases with increasing nanoparticle radius. A comparison between the graphs demonstrates that the effect of inter-particle spacing and nanoparticle radius on Be is opposite to that of entropy generation. The entropy generation rate increases with increasing Ec. Moreover, Nu increases with increasing inter-particle spacing and decreases with increasing nanoparticle radius. As λ increases, temperature and entropy increase, and Be decreases.