Abstract
In this study, the heat transfer enhancement was made by using multiwalled carbon nanotubes (MWCNTs) with distilled water (i.e . nanofluid) in a coiled agitated vessel. The thermal conductivity of the nanofluid at a volume fraction of (0.3 Vol%) was estimated with different parameters (temperature, propeller speed, flow rate, and time ultrasonication). The statistic program Minitab software 2019 by the method of Box–Behnken design (BBD) was used to identify the important and effective parameters of the process. The optimum parameters were found 55°C,300 rpm, 1 L/min, and time ultrasonication of 100 min with enhanced thermal conductivity of about 76.5%.
