Thermal convection for a thermodependent Herschel-Bulkley fluid in an annular duct

This article presents a numerical and experimental investigation of the thermal convection for a thermodependent Herschel-Bulkley fluid in an annular duct under the conditions of a uniform heat flux density on the outer wall and an insulated inner wall. In the numerical analysis, it is assumed that: (i) the rheological behavior of the fluid can be expressed through the Herschel-Bulkley law: tau=tau(s) + K gamma(.n); (ii) the flow is fully developed at the inlet; (iii) all fluid properties except consistency index K are constant. The K-T relation used is K=K(0)exp (-bT). The results obtained enable us to characterize completely the dynamical and thermal fields. The numerical solution is in good agreement with the experimental data, showing the reasonableness of the computed results.