Investigation on the Effect of Length and Amplitude of Sinusoidal Wavy Vortex Generators on the Heat Transfer Rate, Pressure Drop, and London Factor in Compact Heat Exchangers

Abstract

Compact heat exchangers (CHE) improve the heat transfer rate with lighter weight and lower volume than other counterparts. An important point in CHEs is their higher pressure drop relative to conventional heat exchangers. This study aims to investigate the heat transfer rate and pressure drop in some proposed models of these heat exchangers with/without vortex generators (VGs) in different cases. A hot fluid of temperature 350°C flowing through tubes and a cold fluid of temperature 300°C circulating inside the shell are assumed. To this end, several VGs with sinusoidal wavy shapes are designed and examined with different amplitudes of the sine wave and different lengths to determine the effects of these parameters on the heat transfer rate of tubes and pressure drop along the heat exchanger length. In the 2D steady-state laminar fluid flow, governing equations are discretized using the finite element method and analyzed for Reynolds numbers 400 to 1000 in the ANSYS software. Finally, with a 5.06% increase in the Nusselt number, the sinusoidal VGs of amplitude 1 and length 6 mm quantitatively indicated the best performance in terms of the heat transfer rate and pressure drop (London factor) among the studied cases.