Unsteady flow and heat transfer of power-law nanofluid thin film over a stretching sheet with variable magnetic field and power-law velocity slip effect

- We build the power-law fluid governing equations with variable thermal conductivity.
- We obtain the similarity solutions of mathematical formulation.
- The solid volume fraction promotes heat transfer of the liquid film significantly.
- Nanoparticle CuO has more remarkable effect on enhancing heat transfer of EVA melt.
- Increase in local slip parameter shows an enhancement in the temperature.

This paper studies the flow and heat transfer of the power-law nanofluid thin film due to a stretching sheet with magnetic field and velocity slip effects. Unlike classical work, Fourier's law is modified by assuming that the thermal conductivity is power-law-dependent on the velocity gradient. Meanwhile, the power law wall temperature and the power law velocity slip effects are taken into account. Three different types of nanoparticles, Al2O3, TiO2 and CuO are considered with ethylene vinyl acetate copolymer (EVA) used as a base fluid. The governing equations are solved by using DTM-NIM which is combined the differential transform method (DTM) with Newton Iteration method (NIM). The results show that for the specific physical parameters, the two different velocity profiles have always an intersection which goes from a far-field region to the stretching sheet as increasing velocity slip parameter. Furthermore, CuO-EVA nanofluid has better enhancement on heat transfer than TiO2/Al2O3-EVA.

This paper presents an analysis for the flow and heat transfer of power-law thin liquid film over a stretching sheet with magnetic field and velocity slip effects. With the assumption of the thermal conductivity is power-law-dependent on the velocity gradient. Three different types of nanoparticles, Al2O3, TiO2 and CuO are considered with ethylene vinyl acetate copolymer (EVA) used as a base fluid. The results show that CuO has more remarkable effect on enhancing heat transfer of EVA melt than TiO2 and Al2O3. Furthermore, increase in slip parameter shows an enhancement in the temperature and thinner film thickness. 127