Dual solutions of a boundary layer problem for MHD nanofluids through a permeable wedge with variable viscosity

Considering the effect of variable viscosity and the phenomenon of flow separation, the MHD Cu/Ag-Water nanofluids through a permeable wedge are investigated. The governing equations of flow and energy are reduced by similarity transformations and then solved numerically by the shooting method. It is found that dual solutions exist for negative pressure gradient. Compared with the Ag-Water nanofluid, the flow separation occurs later for injection, while it occurs earlier for suction in the Cu-Water nanofluid. The outcomes also specify that suction and small variable viscosity parameters delay the separation for the two nanofluids.