29. Numerical Simulation of Heat Transfer to TiO₂-Water Nanofluid Flow in a Double-Tube Counter Flow Heat Exchanger

Recently, the means of improvement of heat transfer has been rapidly studied. One of the methods that enhance the heat transfer is by changing the heat exchanging fluids. The poor heat transfer coefficient of common fluids compared to the most solids becomes the primary obstacle to design high compactness and effectiveness of heat exchanger. The primary objective of this chapter is to conduct the study of the heat transfer between the water and nanofluid. Both of the fluids were flowed in the horizontal counter flow heat exchanger under the turbulent flow condition. The flow velocity of the fluids varied with Re between 4,000 and 18,000. Literature review states that the heat transfer coefficient of nanofluid is higher than the water by about 6–11 %. Heat transfer to the nanofluid and water is investigated using a computer fluid dynamics software. Ten percent heat transfer augmentation is observed utilizing nanofluid as heat exchanging fluid compared to water. The results also showed the enhancement of the Reynolds number increases the heat transfer to the nanofluid studied in this investigation.