HEAT TRANSFER ENHANCEMENT STUDIES OF WATER DISPERSED WITH MULTI WALLED CARBON NANO TUBES IN A CROSS FLOW RADIATOR

摘要

This paper summarizes a recent work on the enhancement of heat transfer in the radiator using nanofluids. It covers forced convective heat transfer of water dispersed with Multi Walled Carbon Nano Tubes (MWCNTs) in a cross flow radiator test rig with air as cooling liquid. A radiator test rig is designed to simulate the flow regime on automobile radiator. Experiments are conducted with 0.025%, 0.05% and 0.1% mass concentrations of MWCNTs dispersed in water. Air velocities maintained across radiator are 5 m/s, 10m/s and 15m/s. The flow Reynolds number of water is in the range of 2500 to 6000 indicating developing flow regime. The results show that, there is a significant improvement in thermal conductivity of the water with dispersion of MWCNTs in water compared to normal water. The inside heat transfer coefficient and overall heat transfer coefficient has also improved markedly. The improvement in heat transfer coefficient and overall heat transfer coefficient is dependent upon velocity of air and flow rate of coolant.