Heat transfer of nanofluids considering nanoparticle migration and second-order slip velocity

The heat transfer of a magnetohydrodynamics nanofluid inside an annulus considering the second-order slip condition and nanoparticle migration is theoretically investigated.A second-order slip condition,which appropriately represents the non-equilibrium region near the interface,is prescribed rather than the no-slip condition and the linear Navier slip condition.To impose different temperature gradients,the outer wall is subjected to q2,the inner wall is subjected to q1,and q1 > q2.A modified two-component four-equation non-homogeneous equilibrium model is employed for the nanofluid,which have been reduced to two-point ordinary boundary value differential equations in the consideration of the thermally and hydrodynamically fully developed flow.The homotopy analysis method(HAM) is employed to solve the equations,and the h-curves are plotted to verify the accuracy and efficiency of the solutions.Moreover,the effects of the physical factors on the flow and heat transfer are discussed in detail,and the semi-analytical relation between N uB and NBT is obtained.