Thermo-hydraulic performance evaluation of heat exchanger tube with vortex generator inserts

Abstract

This work is undertaken as a scientific experiment to test a new design of a turbulent generator. The current research experiments the influence of novel vortex generator (VG )inserts on heat transfers within a tube under a uniform heat flux. A copper tube with a 45 mm inner diameter and 1,350 mm length is used along with a solid disc injector (swirl generator) that comprises ten crescent holes with equal circumferential distribution angles around the disk canter. Subsequently, a swirl flow is generated by deviating the stream flow 45 degrees causing it to spin in the direction of the axial flow. Flow directors are on 45? angles toward the axial direction for each of the crescent holes. This study is an example of flow degradation. Reynolds numbers (Re). range from 6000 to 13500. Therefore, fluid flow is treated as a turbulent system. All experiments done with air are regarded as a power fluid; the Prandtl number is fixed at about 0.71. Thermo-hydraulic performance of heat exchanger is analyzed. The average heat transfer Nusselt number is calculated and discussed. The experiment found out that Nusselt number (Nu) increases with an increase in Re. as well as the number of swirl generators. At four vortex generators (VGs), the maximum augmentation in heat transfer is around 4.3 times greater than the plain tube and friction factor is about 1.28 with 5 VG insets. The results indicate a promising heat exchanger enhancement in the local petroleum industries.