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Étude de l’interaction micro-tourbillon parois chauffées : application aux transferts de chaleur dans les microcanaux

Abstract : The purpose of this research paper is to determine the role of vortical structures in the improvement of microfluidic cooling systems’ efficiency.This study is presented in two parts. The aim of the first part is to measure heat transfers produced by vortices while interacting with a hot wall. This part was carried out numerically following two steps. The aim of the first step was to improve the understanding of the processes involved during heat transfers in a vortex convected in a laminar flow. As a result, two major processes can be highlighted : the advection of cold particles to the hot wall and an advective mixing. Following these observations, heat transfers produced by a vortical structure were optimized in accordance with its initial characteristics. Consequently, the optimization of heat transfers increased microfluidic cooling systems’ efficiency by more than 50% in the case of vortex streets.The second part combines an experimental study with a numerical model. This study focuses on the creation of vortical structures on a microscopic scale. For this purpose, vortical structures are produced by combination of a synthetic micro jet with a crossflow. The outcome is that several topologies of vortical structures can be observed depending on the Reynolds number of the jet and the crossflow. These topologies can be mapped according to the Reynolds numbers of the system. As a result, a connection can be made between characteristics of some topologies of vortices and control parameters of the system. As a conclusion, the type of structures produced by the cooling system can be controlled
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https://tel.archives-ouvertes.fr/tel-02434513
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Submitted on : Friday, January 10, 2020 - 10:44:26 AM
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  • HAL Id : tel-02434513, version 1

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Dimitri Mutschler. Étude de l’interaction micro-tourbillon parois chauffées : application aux transferts de chaleur dans les microcanaux. Mécanique des fluides [physics.class-ph]. Université de Lyon, 2019. Français. ⟨NNT : 2019LYSE1112⟩. ⟨tel-02434513⟩

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