Numerical investigation on the aerodynamic noise and heat transfer characteristics of continuous helical channels with tube bundles

Abstract

The demand for heat transfer in various industries has been growing rapidly in recent years, which creates severe demands on heat exchangers with high efficiency. The development of low-noise level heat exchangers is critical for submarines and other highly stealthy equipment. Based on the flow properties in the shell-side of shell and tube heat exchanger with continuous helical baffles, the fully and confined helical channels with single tube and tube bundles are established in this paper. Computational fluid dynamics and Aero-acoustic theory are combined to examine the heat transfer and flow noise propagation mechanism inside the helical channels. The results show that the helical channel with helix angle β = 40° exhibits the best overall performance for both single tube and tube bundles. This configuration not only achieves higher heat transfer efficiency but also maintains lower sound pressure levels. As the Reynolds number increases, the pressure drops, the Nusselt number and the sound pressure level all increase. The helical flow within the helix channels contributes to improving the heat transfer performance. The heat transfer performance is enhanced by 2.8∼22.0 % compared with the straight channel. Notably, the maximum sound pressure level observed in the helical channel at a helix angle of β = 40°, which registers at 69.22 dB, lies intermediate to the values recorded for the straight channels and other helical channels. The research can not only highlight the low-noise advantages of helical baffles but also offer new design guidance for noise and vibration suppression in heat exchangers.