NUMERICAL INVESTIGATION OF TRIPLE CONCENTRIC−TUBE HEAT EXCHANGER USING Al2O3-WATER NANOFLUIDS
The heat transfer and pressure drop characteristics of
Al2O3−water nanofluid flowing in a triple concentrictube heat exchanger under laminar-turbulent(low Re) flow conditions are investigated. CFD has been employed for simulating the flow behavior. Reynolds
number for the hot nanofluid was considered in the range of 990-4480 with a nanoparticle volume concentration of 0-2%. The effects of nanoparticle volume concentration, flow rate and flow arrangement on heat transfer and pressure drop of hot nanofluid has been studied. Nusselt number, friction factor and
thermal performance factor have been obtained to interpret the results of the study. It was observed that the addition of nanoparticles (in the range mentioned) resulted in significant enhancement in heat transfer while incurring a slight pressure drop, compared to base fluid. In addition, the increase in flow rate (Reynolds number) also caused a greater heat transfer
while reducing friction factor. With regard to the flow
arrangement, counter flow always provided a better result than parallel flow.