Scale effects on ejector performance: The critical role of boundary layer dynamics.
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| Title: | Scale effects on ejector performance: The critical role of boundary layer dynamics. |
|---|---|
| Authors: | Lin, Zichen1 (AUTHOR), Jiang, Wenlong1 (AUTHOR), Zhang, Chenghu1 (AUTHOR) chenghu.zhang@163.com, Lin, Jiyou2 (AUTHOR) |
| Source: | International Communications in Heat & Mass Transfer. Mar2026:Part 6, Vol. 172, pN.PAG-N.PAG. 1p. |
| Subjects: | Reynolds number, Boundary layer equations, Energy conversion, Vortex motion, Turbulent mixing |
| Abstract: | Ejectors are widely employed in various industries. However, conventional design approaches often overlook the impact of scale effects on ejector performance, resulting in limited predictive accuracy and impeding further improvements in thermodynamic efficiency. This study systematically investigates how boundary layer development serves as a key factor in scaling geometrically similar ejectors. The flow characteristics and energy dissipation mechanisms are analyzed through the development of multi-scale thermodynamic models and high-fidelity computational fluid dynamics simulations. The results demonstrate that small-scale ejectors exhibit a relatively thicker boundary layer and higher wall shear stress due to lower Reynolds numbers, resulting in increased frictional losses and reduced isentropic efficiency. Furthermore, under lower Reynolds number conditions, enhanced vortex breakdown and turbulent dissipation contribute to higher entropy generation. In contrast, large-scale ejectors maintain more stable sonic line distributions and superior resistance to adverse pressure gradients, thereby achieving higher critical back pressures and entrainment ratios. An exponential correlation is proposed to correct the entrainment ratio across different scales, significantly improving prediction accuracy. These findings provide novel insights into ejector scale mechanisms and offer a practical framework for optimizing ejector design in advanced energy systems, particularly in applications requiring miniaturization and high thermodynamic perfection. • Entrainment ratio and critical back pressure reduce exponentially with reduced scale. • The absolute Reynolds number is the fundamental cause of the scale effects. • Small ejectors have thicker boundary layers and increased friction. • Lower Reynolds number enhances local vortex breakdown and turbulent dissipation. • An exponential-based correlation is proposed to correct the entrainment ratio. [ABSTRACT FROM AUTHOR] |
| Copyright of International Communications in Heat & Mass Transfer is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.) | |
| Database: | Engineering Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: egs DbLabel: Engineering Source An: 191707003 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Scale effects on ejector performance: The critical role of boundary layer dynamics. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Lin%2C+Zichen%22">Lin, Zichen</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Jiang%2C+Wenlong%22">Jiang, Wenlong</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22Zhang%2C+Chenghu%22">Zhang, Chenghu</searchLink><relatesTo>1</relatesTo> (AUTHOR)<i> chenghu.zhang@163.com</i><br /><searchLink fieldCode="AR" term="%22Lin%2C+Jiyou%22">Lin, Jiyou</searchLink><relatesTo>2</relatesTo> (AUTHOR) – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22International+Communications+in+Heat+%26+Mass+Transfer%22">International Communications in Heat & Mass Transfer</searchLink>. Mar2026:Part 6, Vol. 172, pN.PAG-N.PAG. 1p. – Name: Subject Label: Subjects Group: Su Data: <searchLink fieldCode="DE" term="%22Reynolds+number%22">Reynolds number</searchLink><br /><searchLink fieldCode="DE" term="%22Boundary+layer+equations%22">Boundary layer equations</searchLink><br /><searchLink fieldCode="DE" term="%22Energy+conversion%22">Energy conversion</searchLink><br /><searchLink fieldCode="DE" term="%22Vortex+motion%22">Vortex motion</searchLink><br /><searchLink fieldCode="DE" term="%22Turbulent+mixing%22">Turbulent mixing</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Ejectors are widely employed in various industries. However, conventional design approaches often overlook the impact of scale effects on ejector performance, resulting in limited predictive accuracy and impeding further improvements in thermodynamic efficiency. This study systematically investigates how boundary layer development serves as a key factor in scaling geometrically similar ejectors. The flow characteristics and energy dissipation mechanisms are analyzed through the development of multi-scale thermodynamic models and high-fidelity computational fluid dynamics simulations. The results demonstrate that small-scale ejectors exhibit a relatively thicker boundary layer and higher wall shear stress due to lower Reynolds numbers, resulting in increased frictional losses and reduced isentropic efficiency. Furthermore, under lower Reynolds number conditions, enhanced vortex breakdown and turbulent dissipation contribute to higher entropy generation. In contrast, large-scale ejectors maintain more stable sonic line distributions and superior resistance to adverse pressure gradients, thereby achieving higher critical back pressures and entrainment ratios. An exponential correlation is proposed to correct the entrainment ratio across different scales, significantly improving prediction accuracy. These findings provide novel insights into ejector scale mechanisms and offer a practical framework for optimizing ejector design in advanced energy systems, particularly in applications requiring miniaturization and high thermodynamic perfection. • Entrainment ratio and critical back pressure reduce exponentially with reduced scale. • The absolute Reynolds number is the fundamental cause of the scale effects. • Small ejectors have thicker boundary layers and increased friction. • Lower Reynolds number enhances local vortex breakdown and turbulent dissipation. • An exponential-based correlation is proposed to correct the entrainment ratio. [ABSTRACT FROM AUTHOR] – Name: AbstractSuppliedCopyright Label: Group: Ab Data: <i>Copyright of International Communications in Heat & Mass Transfer is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites without the copyright holder's express written permission. Additionally, content may not be used with any artificial intelligence tools or machine learning technologies. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract.</i> (Copyright applies to all Abstracts.) |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1016/j.icheatmasstransfer.2026.110724 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 1 StartPage: N.PAG Subjects: – SubjectFull: Reynolds number Type: general – SubjectFull: Boundary layer equations Type: general – SubjectFull: Energy conversion Type: general – SubjectFull: Vortex motion Type: general – SubjectFull: Turbulent mixing Type: general Titles: – TitleFull: Scale effects on ejector performance: The critical role of boundary layer dynamics. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Lin, Zichen – PersonEntity: Name: NameFull: Jiang, Wenlong – PersonEntity: Name: NameFull: Zhang, Chenghu – PersonEntity: Name: NameFull: Lin, Jiyou IsPartOfRelationships: – BibEntity: Dates: – D: 10 M: 03 Text: Mar2026:Part 6 Type: published Y: 2026 Identifiers: – Type: issn-print Value: 07351933 Numbering: – Type: volume Value: 172 Titles: – TitleFull: International Communications in Heat & Mass Transfer Type: main |
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