5. Summary
In this paper, nanofluid is used to achieve the heat transfer enhancement in the double tube heat exchanger. The experiment was run using distilled water to establish the accuracy of the experiment. Results from the water as a coolant has been validated by established Dittus and Boelter equation. Once it has been checked that the data accuracy is within the limited error range nanofluid is added as a coolant on the coldside. The concentration of nanofluids was varied at 0.25% and 0.5% by volume fraction at variable inlet temperature. Results from the experiment show significant improvement over the water where maximum Nusselt number rising up to 24.5%. Furthermore it was seen that by increasing inlet temperature heat transfer of nanofluids increases which shows nanofluids dependency on temperature.
