Entropy analysis and melting heat transfer in the carreau thin hybrid nanofluid film flow

Melting heat transfer has a vital role in forming energy storage devices such as flexible thin film supercapacitors. This idea should be welcomed in the thin film theoretical models to sustain technological advancement, which could later benefit humankind. Hence, the present work endeavors to incorporate the melting heat transfer effect on the Carreau thin hybrid nanofluid film flow over an unsteady accelerating sheet. The mathematical model that obeyed the boundary layer theory has been transformed into a solvable form via an apt similarity transformation. Furthermore, the collocation method, communicated through the MATLAB built‐in bvp4c function, solved the model numerically. Non‐uniqueness solutions have been identified, and solutions with negative film thickness are unreliable. The melting heat transfer effect lowers the heat transfer rate without affecting the liquid film thickness, while the Carreau hybrid nanofluid contributes more entropy than the Carreau nanofluid in the flow regime.