Parabolic trough solar collectors (PTSCs) are generally utilized to reach high temperatures in solar-thermal applications. The current work investigates entropy production analysis and the influence of nano solid particles on a parabolic trough surface collector (PTSC) installed within a solar powered ship (SPS). For the current investigation, the non-Newtonian Maxwell type, as well as a porous medium and Darcy–Forchheimer effects, were used. The flow in PTSC was produced by a nonlinear stretching surface, and the Cattaneo–Christov approach was used to assess the thermal boundary layer’s heat flux. Similarity transformation approach has been employed to convert partial differential equations into solvable ordinary differential equations allied to boundary conditions. Partial differential and the boundary conditions have been reduced into a group of non-linear ordinary differential equations. A Keller-box scheme applied to solve approximate solutions of the ordinary differential equations. Single-walled carbon nanotubes -engine oil (SWCNT-EO) and Multiwalled carbon nanotubes/engine oil (MWCNT-EO) nanofluids have been utilized as working fluid. According to the findings, the magnetic parameter led to a reduction in the Nusselt number, as well as an increment in skin friction coefficient. Moreover, total entropy variance over the domain enhanced for flow rates through Reynolds number and viscosity fluctuations were monitored by using Brinkman number. Utilizing SWCNT-EO nanofluid increased the thermal efficiency between 1.6–14.9% in comparison to MWCNT-EO.

Steady electro-magnetohydrodynamic flow of a micropolar nanofluid in the attendance of reactive Casson fluid passing through parallel plates influenced by the rotating system with the implementation of Buongiorno nanofluid model is examined in this study. The momentum transport equation is enhanced by incorporating the electric field. In addition, the influence of reactive species has a vital role that is affecting the flow phenomenon in conjunction with a transverse magnetic field. The physical flow problem is modeled in the form of partial differential equations which are then transformed into nonlinear ordinary differential equations by using appropriate similarity functions and then solved numerically by the usage of the finite element method and procured results are visualized graphically. The outcomes for flow rate, microrotation, temperature, concentration, and engineering quantities distributions are shown in terms of graphical presentation. Momentum and angular momentum transport progressively in nature as the Casson parameter grows. Opposite results of microrotational profiles are found for electric currents in comparison with Hall currents. Both thermophoresis and Brownian motion are found to be significant effects in improving heat transportation phenomena in nanofluids. The existing available literature was utilized to test for validation of the numerical findings.