EXPERIMENTAL STUDY OF CONVECTIVE HEAT TRANSFER OF ALUMINA OXIDE NANOFLUIDS IN TRIANGLE CHANNEL WITH UNIFORM HEAT FLUX

The recent trend application of the nanofluids is used in some industrial equipment such as tube heat exchanger, double pipe exchanger and shell-tube type heat exchanger. The Triangle tubes may be used in the heat exchanger. Thus, this experimental study reports the convective heat transfer performance of the aluminum oxide-water nanofluids flowing in the triangle channel. In this study, the amount of the volume fraction of the Al2O3 used was 0.1 %, 0.2 %, and 0.3 respectively in base-water as the nanofluids and the Reynolds numbers were varied from about 1000 to 7000. The channel was heated by the electric wire coiled along the channel with constant heat flux. The length and the hydraulic diameter of the triangular channel were 750 mm and 7.1 mm respectively. The DC variable speed pump was used to drive the nanofluids in the channel. Five thermocouples were soldered at the outer surface of the channel to measure the surface temperature. At the inlet and outlet of the channel were attached the thermocouples to measure the inlet and the outlet temperature of the nanofluids. The heat absorbed by the fluid was then released in the cooling tower which used an induced draft fan to convince that the nanofluids temperature decreased before entering the inlet section of the channel. The heat transfer characteristics of the nanofluids are compared to that of pure water. The results show that the heat transfer increase with the increase of the Reynolds number and the volume fraction. The increase of heat transfer varies from about 11% to 36%.