The curvature effect on the heat transfer at the end of a bayonet tube with laminar flows

Bayonet tubes, simple refluent heat exchangers, are widely used to heat or cool a media when the heating/cooling agent is readily accessible from one side only. Many studies have been conducted to evaluate the heat transfer performance of bayonet tubes. The majority of these studies focus on the heat transfer in the annular section and little on the end surface. This paper presents a numerical simulation of the laminar flow and heat transfer in a bayonet tube. The simulation is first validated by the experimental data in the literature. The flow and heat transfer in bayonet tubes are then investigated with both flat and curved end surfaces. Both local and average Nusselt number on the end surfaces are calculated under various Re and geometry conditions. Effect of the end surface curvature is studied by comparing the performances of the flat and curved ended bayonet tubes.