Numerical study of flow characteristics and heat transfer mechanism in Tesla valve tube

Abstract

In this study, we conducted a numerical analysis of the flow characteristics and heat transfer mechanism of a Tesla valve. Our aim was to illustrate the improvement in heat transfer by presenting velocity clouds, temperature clouds, pressure clouds, velocity vectors, and local flow lines. The findings of our study indicate that the formation of different vortices at the inlet of the Tesla valve has varying effects on heat transfer and fluid flow in forward and reverse flow scenarios. During forward flow, longitudinal vortices are more likely to form, whereas transverse vortices tend to form during reverse flow. These vortices have the ability to disrupt the boundary layer and enhance heat transfer, resulting in improved heat transfer efficiency, albeit with a slight pressure drop. When the flow angle was increased from 40° to 80°, we observed a decrease in the Nusselt number (Nu) by 17.8 % and 8.1 % in forward and reverse flows, respectively. Conversely, the friction factor (f) increased by 22.6 % and 3.1 %, while the Dittus-Boelter factor (Dit) increased by 11.8 %. In addition, the extension of the lateral groove length from 10 cm to 18 cm resulted in a decrease of 7.5 % and 11.7 % in Nu for forward and reverse flows, respectively. Similarly, f decreased by 13.8 % and 9.1 %, while Dit decreased by 5.2 %. Moreover, mathematical equations were developed to describe the relationship between the lead angle, side channel length, Re, Nu, and f. These findings aim to offer valuable insights for the design and implementation of Tesla valves.

Keywords

• Heat transfer mechanism
• Vortex
• Inflow angle and side channel length
• Power law relationship