Nepal Chandra Roy - Department of Mathematics, University of Dhaka, Dhaka, ۱۰۰۰, Bangladesh
Md. Anwar Hossain - Department of Mathematics, University of Dhaka, Dhaka, ۱۰۰۰, Bangladesh‎
Ioan Pop - Department of Applied Mathematics, Babeş-Bolyai University, Cluj-Napoca, Romania

An unsteady boundary layer flow of a micropolar hybrid nanofluid over a stretching/shrinking sheet is analyzed. The nonlinear ordinary differential equations of the problem have been solved using the efficient implicit Runge–Kutta–Butcher method along with Nachtsheim–Swigert iteration technique. For a certain set of parameters, numerical results expose dual solutions with the change of the velocity ratio parameter. The dual solutions are presented in a wide range of the physical parameters. Using a lot of numerical data, the critical values of the velocity ratio parameter, local friction factor, local couple-stress and local Nusselt number for the existence of dual solutions are expressed as a function of the physical parameters. These expressions might be useful for the development of new technology or for the future experimental investigation.

Dual solutions, Micropolar Fluid, Hybrid nanofluid, stretching or shrinking sheet