To demonstrate the rationalization of multi-longitudinal swirls (MLSs) in heat
exchanger tubes, this paper investigates the thermohydraulic performance of
heat exchanger tube with rectangular vortex generator using numerical
simulation. Comparative analyses of rectangular vortex generators and their
different slotted structures are conducted, along with the investigation
of the effect of the longitudinal pitch (P = 0.1 m, 0.2 mand0.3 m) of the
rectangular vortex generators on the thermohydraulic performance. The
research reveals that the MLSs induced by the vortex generator inside the
tube accelerate the exchange of cold and hot fluids, improve the field
synergies of velocity vectors and temperature gradients, and enhance the heat
transfer efficiency of the heat exchanger tube. The slotted structure
reduces the flow resistance and lowers the degree of disturbance to the
fluid, which reduces the strength of the MLSs, thus weakening the overall
performance of the heat exchanger. The strength of the MLSs has a direct
influence on the overall performance of the heat exchanger tube. With the
increase of P, the performance evaluation criteria (PEC) of the heat
exchanger tubes decreases, and the maximum PEC = 1.44 is obtained for P = 100
mm at the studied Reynolds number range.