Rabha Khatyr^*, Jaafar Khalid Naciri

Frontiers in Heat and Mass Transfer, Vol.19, pp. 1-8, 2022, DOI:10.5098/hmt.19.23

Abstract The aim is to study the asymptotic behavior of the temperature field for the laminar forced convection of a Herschel-Bulkley fluid flowing in a circular duct considering both viscous dissipation and axial heat conduction. The asymptotic bulk and mixing Nusselt numbers and the asymptotic bulk and mixing temperature distribution are evaluated analytically in the cases of uniform wall temperature and convection with an external isothermal fluid. In particular, it has been proved that the fully developed value of Nusselt number for convective boundary conditions is independent of the Biot number and is equal to the More >

Rabha Khatyr^*, Jaafar Khalid Naciri

Frontiers in Heat and Mass Transfer, Vol.15, pp. 1-11, 2020, DOI:10.5098/hmt.15.5

Abstract The present study focuses on the effects of viscous dissipation and axial heat conduction on the asymptotic behavior of the laminar forced convection in a circular duct for a Herschel-Bulkley fluid with variable wall heat flux. Analytical asymptotic solutions are presented for the case of axial variations of the wall heat flux, with finite non-vanishing values at infinity along the flow direction. The asymptotic bulk and mixing Nusselt numbers and the asymptotic bulk and mixing temperature distributions are evaluated analytically in the case of axially variable wall heat flux for which polynomial and logarithmic functions More >