Simulations of acoustically enhanced heat transfer in fluids
Tutor / directorGonzález Cinca, Ricardo
Document typeMaster thesis
Rights accessOpen Access
On Earth, heat dissipation of electronics is produced through convective currents due to gravity, that allow the flow of energy to the environment. However, in microgravity, hot particles remain around the heat source due to the absence of buoyancy. In this project, an existing line of research from the Space Exploration Lab in the UPC is followed in the field of acoustic induced heat transfer in fluids. Our project aims to use acoustic actuation to enhance heat transfer in real microgravity conditions in the ZARM Drop Tower, thanks to the DropYourThesis! 2022 program, from the European Space Agency. The objective of this master thesis is to develop simulations that explain the phenomena and to help design an optimal setup for the study. A simple experiment is proposed with two main systems. The first generates an acoustic wave with a piezoelectric transducer and the second heats up a resistance, which actuates as a heat source. COMSOL Multiphysics is used to develop a validated model that will help us understand the Physics behind this phenomenon and achieve optimal setups to explain the governing factors of this interaction for different gravity levels. It is observed that acoustic heat transfer enhancement is highly dependent on time and gravity acceleration. For normal gravity conditions, the effect is noticeable at short timescales and then buoyancy turns into the dominant heat transfer factor over time. For microgravity conditions, data suggests that the effect is mild at short timescales, but it increases steadily over time without showing signs of regression. Heat transfer in microgravity conditions is increased by 10.9% after 16.2s of acoustic actuation using a resonance frequency of 45kHz. It is concluded that there is high potential for the development of a new cooling technology based on ultrasound in microgravity and this thesis establishes a theoretical framework in which future techniques could be based on.
DegreeMÀSTER UNIVERSITARI EN CIÈNCIA I TECNOLOGIA AEROESPACIALS (Pla 2021)