Multiple solutions of Hiemenz flow of CNTs hybrid base C2H6O2+H2O nanofluid and heat transfer over stretching/shrinking surface: Stability analysis

The purpose of the current article is to numerically and theoretically examine the flow of two-dimensional (2D) steady Hiemenz with the transfer of heat of carbon nanotubes (CNTs) hybrid base C2H6O2+H2O (Ethylene glycol + water) nanofluid across a linear shrinking/stretching surface. The equations of Navier–Stokes have been converted into equations of self-similar applying suitable transformations of similarity variables, and then numerically resolved using the three-stage Labatto-three-A formula. In addition, an endeavor is made to extend the behavior of asymptotic of the solution to massive stretching. The comparison between the found asymptotic solutions and previously reported numerical results is rather impressive. Observations indicate that equations of self-similar display double solutions within the restricted shrinking parameter range. There exists one solution for every case of stretching. In the first solution, the impacts of nanoparticle solid volume fraction and shrinking parameters on velocity and thermal fields exhibit an increasing trend. Consequently, the linear analysis of temporal stability has been performed to establish the most fundamentally viable option. The smallest eigenvalue sign determines whether a solution is unstable or stable for the purposes of stability analysis. The analysis of stability demonstrates that the first solution describing the primary flow is stable.