Experimental investigation of a novel approach to enhance heat transfer in double-tube heat exchangers through the utilization of a vibrating latex strip turbulator

Abstract

This study introduces a novel approach aimed at mechanically influencing and distorting the boundary layer. This is achieved through the utilization of a wide, thin, elongated vibrating turbulator made of latex. The advanced vibrating turbulator continuously sweeps the inner tube perimeter, effectively breaking the boundary layer. Located within the test section is a concentric copper tube, defined by an outer diameter of $2.5\mathrm{cm}$ and an inner diameter of $1.6\mathrm{cm}$. The effect of a number of parameters on the thermal characteristics of the heat exchanger, including the thickness of the latex turbulator, the width of the latex turbulator, the flow rate through the inner tube and the oscillation frequency, is investigated. The inner diameter of the tube sets the minimum width for the latex turbulator. The findings show a substantial rise in the heat transfer rate, reaching up to 504.5 %, when the rubber strip dimensions and frequency are optimized to a width of $22\mathrm{mm}$, thickness of $0.4\mathrm{mm}$, and frequency of $40\mathrm{Hz}$. Under these conditions, the thermal enhancement factor reaches a peak of 3.39. Moreover, the thermal performance decreases when the rubber thickness is increased.