Numerical analysis of heat transfer in tubular type heat exchangers of transport vehicles with pulsating flow

Abstract

The shell and tube heat exchangers are widely used in many engineering applications. Tubular heat exchangers can be found in the transport, power engineering, food industry and etc. Therefore, the study of the characteristics of heat transfer and hydrodynamics in tubular heat exchangers is important. In this paper, numerical analysis of a heat transfer in a staggered tube bundle with steady and asymmetrical pulsating flow studied. The transverse and streamwise spacing-to-diameter ratios of the tube bundle were 1.3. The Reynolds number Re was 1100. Numerical simulation of the flow past the tube bundle with 7 longitudinal rows was carried out by solving the incompressible Navier-Stokes equations and energy conservation equation with two different modeling strategies. The simulation was carried out with the RNG k-ε turbulence model with enhanced wall treatment and laminar solver. The sensitivity of the Nusselt number to the mesh parameters is noted. The effect of the number of rows of the tube on the heat transfer rate for the tube bundle with the pulsating flow also was discussed. For the pulsating flow enhancement of the heat transfer in the tube bundle dependence from the row of the tube and modeling strategy. When RNG k-ε turbulence model was employed the heat transfer rate of the first row is increasing by 16 %, downstream rows by 6-7 %. When laminar solver was employed the heat transfer rate of the central rows are increasing by 53 %.