Physical aspects of entropy optimization in mixed convective MHD flow of carbon nanotubes (CNTs) in a rotating frame

The aim of this article is to investigate the physical aspects of entropy optimization in mixed convective magnetohydrodynamic flow of carbon nanotubes (CNTs) in a rotating frame. Flow is generated due to stretching of the sheet. The mechanism of nanoparticles transport is obtained by using the Xue model. Here we have used water as a base fluid. Both single-wall carbon nanotubes (SWCNTs) and multi-wall carbon nanotubes (MWCNTs) are considered as nanoparticles in base fluid. The energy equation is modeled subject to viscous dissipation and heat source/sink. With the help of second laws of thermodynamics total entropy generation rate is calculated. Physical importance of single and MWCNTs are discussed graphically. Nonlinear partial systems are converted to ordinary ones through appropriate transformations. The obtained governing systems are solved through OHAM for series solutions. Characteristics of different physical variables on velocity, entropy generation, Bejan number and temperature are discussed via graphs. Surface drag force and heat transfer rate are computed numerically for both SWCNTs and MWCNTs. The obtained result presents that surface drag force and heat transfer rate are increased via larger nanoparticles volume friction. Entropy generation rate is enhanced for higher values of magnetic parameter and Brinkman number. Furthermore, Bejan number is maximum for Br=0 and then gradually decreases for larger values of Brinkman number.