Analysis of axial annular flow for viscoelastic fluid with temperature dependent properties

Analytical solutions using Homotopy Perturbation Method (HPM) are obtained for viscoelastic and shear-thinning fluid obeying simplified Phan-Thien-Tanner (SPTT) constitutive equation in concentric annulus under steady, laminar, fully developed and axial flow with variable thermo physical properties. The isoflux boundary conditions are employed at both walls and the Reynold's model is considered for temperature-dependent viscosity and relaxation time. Results show that increasing fluid elasticity (εDe2) causes Nusselt number to rise and the difference between annular fluid temperature and wall temperature to drop while the Brinkman number and α parameter have the opposite effect. Also effects of Brinkman number, fluid elasticity (εDe2) and α parameter on velocity profile are similar, i.e., any increase in all there parameters causes the velocity profile to become flatter. Influence of variable physical properties gets weaker by increasing fluid elasticity.