Experimental investigation on heat transfer and pressure drop characteristics in a smooth tube with different twisted tape inserts

Abstract

Experiments are performed to investigate the impact of inserts (TTI, TBI, and TBHI) accompanied by different twist ratios (ie, y/w = 3.69, 4.39, and 5.25) with uniform heat flux condition to study the performance characteristics of pressure drop, rate of heat flow, and heat transfer enhancement. Experiments were carried out on different twisted tape inserts in a turbulent flow regime by choosing suitable Reynolds number between 3100 and 39 000. A plain tube is tested and compared with the empirical correlations and are found to be in good agreement with the experimental data. In the case of twisted tape inserts stronger swirl flow is observed along the length of the tube. The variation of reduction in pressure along the length of tube and heat flux in the form of the friction factor and Nusselt number are represented graphically. Thermal performance factor tends to increase with a decrease in the taper twist ratio. The maximum enhancement in Nusselt number and friction factor was found to be in the case of TBI and TBHI. Experimental results are justified and are found to be reliable and accurate with the analytical results, with ±5% and ±4.2% deviation for Dittus‐Boelter and Petukhov correlation in the case of Nusselt number and ±7.2% deviation, respectively, for loss in the friction.

Numerical and Experimental Studies on Heat Transfer Enhancement in a Circular Tube Inserted with Twisted Tape Inserts

“…Since heat exchangers were applied in various industries such as oil industry, chemical industry, vehicle and aerospace, the efficiency of heat exchange has been an important factor affecting profits of enterprises. To improve the efficiency of heat exchange, a large number of researches about heat transfer enhancement were made [1][2][3][4]. The main methods of heat transfer enhancement could be divided into three aspects: active methods, passive methods and compound methods.…”