Hydrodynamic and Thermal Slip Effect on Double-Diffusive Free Convective Boundary Layer Flow of a Nanofluid Past a Flat Vertical Plate in the Moving Free Stream

Waqar A Khan,A I Md Ismail,Md Jashim Uddin,Derek Abbott

doi:10.1371/journal.pone.0054024

Abstract

The effects of hydrodynamic and thermal slip boundary conditions on the double-diffusive free convective flow of a nanofluid along a semi-infinite flat solid vertical plate are investigated numerically. It is assumed that free stream is moving. The governing boundary layer equations are non-dimensionalized and transformed into a system of nonlinear, coupled similarity equations. The effects of the controlling parameters on the dimensionless velocity, temperature, solute and nanofluid concentration as well as on the reduced Nusselt number, reduced Sherwood number and the reduced nanoparticle Sherwood number are investigated and presented graphically. To the best of our knowledge, the effects of hydrodynamic and thermal slip boundary conditions have not been investigated yet. It is found that the reduced local Nusselt, local solute and the local nanofluid Sherwood numbers increase with hydrodynamic slip and decrease with thermal slip parameters.

Highlights

Conventional heat transfer fluids have poor heat conductivity and require high velocities or heat transfer coefficients to efficiently transfer this heat from a given surface
The present study attempts to pinpoint the effects of the momentum and thermal slips boundary conditions on the doublediffusive free convective flow of a viscous incompressible nanofluid past a semi-infinite flat heated vertical plate in the moving free stream, which up to date have not been elucidated in the literature
We found that the reduced local Sherwood number is an increasing function of double-diffusive buoyancy, modified Dufour and linear momentum slip parameters both for isothermal and nonisothermal plate

Summary

Introduction

Most physical processes (e.g. in boilers, or in a combustion engines, heat exchangers technology) involve heat generation. The present study attempts to pinpoint the effects of the momentum and thermal slips boundary conditions on the doublediffusive free convective flow of a viscous incompressible nanofluid past a semi-infinite flat heated vertical plate in the moving free stream, which up to date have not been elucidated in the literature.

Results

Conclusion