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Heat transfer and pumping power of water-cooled thermal management systems (TMSs) for lithium-ion batteries (LIBs) in electric vehicles (EVs) are investigated through a three-dimensional computational approach. TMSs are cylindrical shells that cover LIBs. Water flows through the shell and removes heat from LIBs. The focus of this study is to provide practical insights on the effects of number of inlets on the thermal performance and pumping power of TMSs. Two TMSs with one and four inlets at the top of the TMS’s case are considered. Both TMSs include one outlet, which is located at the bottom of the case. The thermal performance of individual TMSs is evaluated by the maximum temperature of the battery cell and the temperature difference across the cell. The thermal performances are described based on the pumping power. Simulations are performed at different flow rates within a laminar regime. Results indicate that both TMSs provide safe operational temperatures for LIBs. However, compared to the one-inlet design, the four-inlet TMS archives the same thermal performance but at a lower pumping power. The lower pumping power is due to lower pressure drop in the four-inlet TMS resulting from flowing water with lower flow rate at individual inlets, and through a shorter path from individual inlets to the outlet, compared with the one-inlet TMS. Minimizing pumping power without any penalty in the thermal performance is significantly beneficial, especially when the TMS is used for a pack of LIBs in EVs.
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Canine-inspired Unidirectional Flows for Improving Memory Effects in Machine Olfaction
Synopsis A dog's nose differs from a human's in that air does not change direction but flows in a unidirectional path from inlet to outlet. Previous simulations showed that unidirectional flow through a dog’s complex nasal passageways creates stagnant zones of trapped air. We hypothesize that these zones give the dog a “physical memory,” which it may use to compare recent odors to past ones. In this study, we conducted experiments with our previously built Gaseous Recognition Oscillatory Machine Integrating Technology (GROMIT) and performed corresponding simulations in two dimensions. We compared three settings: a control setting that mimics the bidirectional flow of the human nose; a short-circuit setting where odors exit before reaching the sensors; and a unidirectional configuration using a dedicated inlet and outlet that mimics the dog’s nose. After exposure to odors, the sensors in the unidirectional setting showed the slowest return to their baseline level, indicative of memory effects. Simulations showed that both short-circuit and unidirectional flows created trapped recirculation zones, which slowed the release of odors from the chamber. In the future, memory effects such as the ones found here may improve the sensitivity and utility of electronic noses.
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- PAR ID:
- 10445357
- Publisher / Repository:
- Oxford University Press
- Date Published:
- Journal Name:
- Integrative And Comparative Biology
- Volume:
- 63
- Issue:
- 2
- ISSN:
- 1540-7063
- Format(s):
- Medium: X Size: p. 332-342
- Size(s):
- p. 332-342
- Sponsoring Org:
- National Science Foundation
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