Experimental investigations of heat transfer processes in the presence of a high-frequency oscillating flow
Heat transfer processes in the presence of steady flow have been extensively investigated, and the physics underlying these processes is well understood. However, heat transfer processes in the presence of oscillating flows are not well established. Oscillating flows are encountered in several engineering fields such as marine, biological engineering, chemical engineering, and thermal engineering. Improving the performance of the engineering applications related to these fields requires a better understanding of the nature of oscillating flows and heat transfer processes in the presence of such oscillating flows.
The significance of heat transfer in the presence of high-frequency oscillating flows is recognized in several applications such as thermoacoustic engines and refrigerators, Stirling engines, and cryogenics (pulsed-tube refrigerators). In these applications, heat is transferred between oscillating gas (usually confined in a duct) and an external fluid stream (e.g. water or air) via a heat exchanger. The performance of these heat exchangers plays a role in the overall performance of these systems. The performance of these heat exchangers can be described by their effectiveness (i.e. ability to transfer the heat between two fluids) and temperature uniformity over their cross-section. These two factors can be influenced by the nature of oscillating flow (i.e. flow and temperature morphologies) around the heat exchanger. Experimental Investigation of flow and temperature fields around a heat exchanger placed inside a duct requires non-intrusive measurement techniques. The Particle Image Velocimetry (PIV) system is usually used to measure such flow fields. There are several non-intrusive techniques for measuring the temperature field such as Planner Laser Induced Fluorescence (PLIF), Thermal cameras, and Background Oriented Schlieren (BOS). However, implementing these techniques for measuring the temperature field inside a duct is quite challenging.
The first objective of the proposed Ph.D. project is to develop a measurement technique to capture the oscillating temperature field around a heat exchanger exposed to an oscillating flow. The second objective is to use this technique along with the PIV technique to understand the heat transfer phenomena in the presence of oscillating flow at different frequencies. Finally, different heat exchanger designs will be developed and tested based on our understanding of heat transfer processes.
Keywords: Oscillating flow; heat transfer; PIV; PLIF.
Requirements and skills of the candidate:
- Master of Engineering
- Good knowledge of acoustic, fluid mechanics, and heat transfer
- Passionate about performing experiments and physical data analysis
- Good knowledge of programming, Matlab is preferred.
Supervisors:
- Islam Ramadan, Enseignant-chercheur, Institut Pprime, université de Poitiers.
- Hélène Bailliet, Enseignante-chercheuse - HDR, Institut Pprime, université de Poitiers.
Application:
Applicants are asked to provide the following documents:
- A detailed CV
- A motivation letter.
These documents should be sent to Dr. Islam Ramadan (islam.ramadan@univ-poitiers.fr).
Starting date: October 1st, 2023.
