Improvement of heat transfer by means of ultrasound: Application to a double-tube heat exchanger

A new kind of ultrasonically-assisted heat exchanger has been designed, built and studied. It can be seen as a vibrating heat exchanger. A comprehensive description of the overall experimental set-up is provided, i.e. of the test rig and the acquisition system. Data acquisition and processing are explained step-by-step with a detailed example of graph obtained and how, from these experimental data, energy balance is calculated on the heat exchanger. It is demonstrated that ultrasound can be used efficiently as a heat transfer enhancement technique, even in such complex systems as heat exchangers.

► A new type of heat exchanger has been studied.
► This heat exchanger body vibrates at 35 kHz.
► The presence of ultrasound results in an improvement of the performances.
► The overall heat transfer coefficient is increased by ultrasound.
► Influence of ultrasound is more intense for laminar flow conditions.