Constructal design of gas-cooled electric power generators, self-pumping and atmospheric circulation

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Bejan, A
Lorente, S
Lee, J
Kim, Y

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© 2015 Elsevier Ltd. All rights reserved. Rotating electric machines generate heat volumetrically, and are cooled by forced convection aided by the self-pumping effect. In this paper we focus on the fundamental relationship between the internal flow architecture of the gas cooled winding and its thermal performance, which is represented by the nearly uniform distribution of peak temperature throughout the winding volume. We show that the cooling passages can be sized such that the volumetric cooling is most effective. From this finding follows the number of passages and their distribution through the heat generating volume. The principle is developed analytically, and it is then validated based on numerical simulations of the cooling architecture. The paper also reports the thermodynamics basis of the self-pumping effect, and its natural occurrence as free convection in general, which includes atmospheric circulation.






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Bejan, A, S Lorente, J Lee and Y Kim (2015). Constructal design of gas-cooled electric power generators, self-pumping and atmospheric circulation. International Journal of Heat and Mass Transfer, 91. pp. 647–655. 10.1016/j.ijheatmasstransfer.2015.07.015 Retrieved from

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Adrian Bejan

J.A. Jones Distinguished Professor of Mechanical Engineering

Professor Bejan was awarded the Benjamin Franklin Medal 2018 and the Humboldt Research Award 2019. His research covers engineering science and applied physics: thermodynamics, heat transfer, convection, design, and evolution in nature.

He is ranked among the top 0.01% of the most cited and impactful world scientists (and top 10 in Engineering world wide) in the 2019 citations impact database created by Stanford University’s John Ioannidis, in PLoS Biology.  He is the author of 30 books and 700 peer-referred articles. His h-index is 111 with 92,000 citations on Google Scholar. He received 18 honorary doctorates from universities in 11 countries.

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