Forced convection heat transfer in square duct with heated and adiabatic walls at constant axial heat flux

Abstract

The paper presents the solution of laminar forced convection in a square duct recessed in thermal insulation. It was assumed that the heated walls have a constant temperature, while on the boundary in contact with the insulation an adiabatic wall was established, and the axial heat conduction in the fluid was neglected. The relationship between the Nusselt number and the ratio of the adiabatic wall height to the height of the square duct, which can be used as a main parameter in the design of micro-heat exchangers, was determined in this work. The paper also presents sample temperature fields and heatlines for selected Nusselt numbers.