Experimental Investigations in a Circular Tube to Enhance Turbulent Heat Transfer Using Mesh Inserts

The present work shows the results obtained from experimental investigations of the augmentation of turbulent flow heat transfer in a horizontal tube by means of mesh inserts with air as the working fluid. Sixteen types of mesh inserts with screen diameters of 22mm, 18mm, 14mm and 10mm for varying distance between the screens of 50mm, 100mm, 150mm and 200mm in the porosity range of 99.73 to 99.98 are considered for experimentation. The Reynolds number is varied from 7000 to 14000. Correlations for Nusselt number and friction factor are developed for the mesh inserts from the obtained results. It is observed that the enhancement of heat transfer by using mesh inserts when compared to plain tube at the same mass flow rate is more by a factor of 2 times where as the pressure drop is only about a factor of 1.45 times.