An alternative approach using numerical modelling for equivalent ultrasound propagation and its application: Prediction of heat transfer performance of a vertically helical-coiled tube heat exchanger induced by ultrasound

摘要

This research presents an alternative approach using numerical modelling for the prediction of simplified ultrasound distribution in a 3D water flow domain. The simulation was conducted using the Ansys-Fluent CFD commercial program. The results from this approach were compared with those from other researchers, covering an ultrasonic power range of 9.6-400 W and a frequency range of 24 kHz-1.7 MHz based on the parameters of mean axial and average velocity, Nusselt number, and the heat transfer coefficient. The maximum and minimum errors for the range of studies were 25.91% and 1.65%, respectively. Hence, this numerical setup can be utilized to achieve accurate prediction of the fluid flow and heat transfer over a controlled space which provides more realistic results for a whole domain with rapid calculation, especially in the far field region. Furthermore, this approach was applied to predict the augmentation of heat transfer in a vertically helical-coiled tube exchanger using 24 kHz ultrasonic waves. With very low numerical error, the results showed that the maximum thermal performance factor was 19% and 33% when the waves were emitted from one and two ultrasonic transducers at positions UT12 and UT12.9, respectively.