Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Conference Object Citation - Scopus: 1Liquid Cooling of Li-Ion Cells Based on a Constructal Canopy-To Approach(American Society of Mechanical Engineers (ASME), 2024) Gungor,S.; Cetkin,E.; Lorente,S.While many countries ambition to transition to clean energy, challenges appear related to the new developed technologies. This is particularly the case when it comes to electric vehicles and their batteries. The technology of the latter is based on Lithium-ion electrochemical reactions. During the batteries discharge, the electrochemical reactions are exothermic, and they are endothermic during the charging phase. The large change in temperature threatens the life duration of the batteries, and when combined to other factors, their safety. Therefore, the thermal management of the electric vehicle battery pack is a critical aspect that requires specific attention. In this paper, we present the work conducted by our group on thermally efficient solutions for maintaining the battery cells within the temperature range expected by manufacturers. The thermal management solution consists in inserting between the battery cells a constructal-based liquid cooling system. Such systems are called canopy-To-canopy architectures. The cooling fluid is driven from a trunk channel to perpendicular branches that make the tree canopy. An opposite tree collects the liquid in such a way that the two trees match canopy-To-canopy. The results indicate that such configurations allow to extract most of the non-uniformly generated heat by the battery cell during the discharging phase, while using a small mass flow rate. Furthermore, the configuration with 5 branches appears to be the one with high thermal efficiency and low pumping power. Copyright © 2024 by ASME.Article Citation - WoS: 83Citation - Scopus: 95Canopy-To Liquid Cooling for the Thermal Management of Lithium-Ion Batteries, a Constructal Approach(Elsevier Ltd., 2022) Güngör, Şahin; Çetkin, Erdal; Lorente, SylvieWith the growing interest on electric vehicles comes the question of the thermal management of their battery pack. In this work, we propose a thermally efficient solution consisting in inserting between the cells a liquid cooling system based on constructal canopy-to-canopy architectures. In such systems, the cooling fluid is driven from a trunk channel to perpendicular branches that make the tree canopy. An opposite tree collects the liquid in such a way that the two trees match canopy-to-canopy. The configuration of the cooling solution is predicted following the constructal methodology, leading to the choice of the hydraulic diameter ratios. We show that such configurations allow extracting most of the non-uniformly generated heat by the battery cell during the discharging phase, while using a small mass flow rate.Article Citation - WoS: 1Citation - Scopus: 1Constructal Structures With and Without High-Conductivity Inserts for Self-Cooling(International Information and Engineering Technology Association, 2016) Çetkin, ErdalHere we show how a heat generating domain can be gained self-cooling capability with embedded cooling channels and with and without high-conductivity fins. The volume of the heat generating domain is fixed, so is the overall volume of the cooling channels and high-conductivity inserts. Even though the coolant volume decreases with embedded high-conductivity fins, the peak temperature also decreases with high-conductivity inserts. The peak temperature is affected by the location, shape and complexity of the fins and the volume fraction. This paper documents how these degrees of freedoms should be changed in order to minimize peak temperature. This paper also discusses how the volume fraction affects each fin shape in order to minimize the peak temperature. This paper uncovers that the fins should be distributed non-equidistantly, and that high-conductivity material should be inserted as fins (bulks of high-conductivity materials) rather than uniform distribution in the domain. This paper concludes that the overall thermal conductance of a heat generating domain can be maximized by freely morphing the shape of the high-conductivity material. The optimal design exists for given conditions and assumptions, and this design should be morphed when conditions and assumptions change. This conclusion is in accord with the constructal law. Each optimal design for given conditions and assumptions is the constructal designArticle Citation - WoS: 10Citation - Scopus: 10Constructal Microdevice Manifold Design With Uniform Flow Rate Distribution by Consideration of the Tree-Branching Rule of Leonardo Da Vinci and Hess-Murray Rule(The American Society of Mechanical Engineers(ASME), 2017) Çetkin, ErdalIn this paper, we show how the design of a microdevice manifold should be tapered for uniform flow rate distribution. The designs based on the tree-branching rule of Leonardo da Vinci and the Hess-Murray rule were considered in addition to the constructal design. Both da Vinci and Hess-Murray designs are insensitive to the inlet velocity, and they provide better flow uniformity than the base (not tapered) design. However, the results of this paper uncover that not only pressure drop but also velocity distribution in the microdevice play an integral role in the flow uniformity. Therefore, an iterative approach was adopted with five degrees-of-freedom (inclined wall positions) and one constraint (constant distribution channel thickness) in order to uncover the constructal design which conforms the uniform flow rate distribution. In addition, the effect of slenderness of the microchannels (Svelteness) and inlet velocity on the flow rate distribution to the microchannels has been documented. This paper also uncovers that the design of a manifold should be designed with not only the consideration of pressure distribution but also dynamic pressure distribution especially for non-Svelte microdevices.