An experimental study on influence of surface corrugations to heat transfer using double pipe heat exchanger

The incorporation of surface irregularities on the heat transfer surface is taking its attention because it enhances the thermo- hydraulic characteristics of the heat exchanger. However, the thermal performance enhancement and pressure drop increment comes parallel with heat transfer enhancement technique. But, in some applications, it is highly appropriate to provide surface roughness where space consideration is more vital to power loss as a result of pressure drop, namely on aerospace industry and nuclear reactors. The objective of this research is to study experimentally on the effect of surface corrugations to heat transfer using double pipe heat exchanger. The fiction factor and heat transfer parameters are obtained in the turbulent regime and the weight age of the both factors are compared with the help of thermal performance factor. The experimental data obtained from WILSON PLOT is validated with the data obtained from empirical relations. One smooth tube of 25 mm diameter and two enhanced tubes of same diameter with V corrugations on the outer surface having surface height, e = 0.3 mm and e = 0.6 mm and pitch, p = 1.3 mm are used. The corrugated tubes are found to be more advantageous than smooth tube for heat transfer applications. The percentage of heat transfer enhancement for tube with e = 0.3 mm is found to be 68 % to 51% and for a tube of e = 0.6 mm, is 90 % to 65 % in the Reynolds number regime of 16700 to 22300.The friction factor for the tube with e = 0.6 mm is found to be greater as compared to tube with e = 0.3 mm.