{"title":"可压缩湍流中的螺旋力传递","authors":"Zheng Yan, Junfeng Wu, Zhu Lei, Jianchun Wang, Lifeng Wang, Xinliang Li, Changping Yu","doi":"10.1103/physrevfluids.9.094603","DOIUrl":null,"url":null,"abstract":"The dual-channel characteristics of large-scale helicity transfer in compressible turbulent flows, including subgrid-scale (SGS) and viscosity terms, are investigated. After selecting a suitable definition for large-scale helicity, we confirm the existence of the dual channel of SGS and viscosity terms of large-scale helicity governing equations and theoretically prove that no dual pressure term channel exists. The second channel of the SGS and viscosity terms also consists of two terms, which originate from the rotation of the SGS stress and the baroclinic of the velocity and density gradients, respectively. The identical relationship of the ensemble averages of the dual channel of SGS and viscosity terms can be theoretically and numerically confirmed, whereas their second channel which is associated with shocklets is more intermittent. For the SGS term, the compression regions are dominant in contrast to the expansion regions, and the strain regions are dominant in contrast to the rotation regions in the inertial scale range. The viscous dissipation mechanism of large-scale helicity differs from that of large-scale kinetic energy. It is dominated by the first channel on the inside of the vortex structure and by the second channel on the outside. The further decompositions of the second channel of the SGS and viscosity terms provide a possible mechanism for the inverse helicity transfer. This means that expansion motions promote inverse helicity transfer through the second terms of their second channels.","PeriodicalId":20160,"journal":{"name":"Physical Review Fluids","volume":null,"pages":null},"PeriodicalIF":2.5000,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Helicity transfer in compressible turbulent flows\",\"authors\":\"Zheng Yan, Junfeng Wu, Zhu Lei, Jianchun Wang, Lifeng Wang, Xinliang Li, Changping Yu\",\"doi\":\"10.1103/physrevfluids.9.094603\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The dual-channel characteristics of large-scale helicity transfer in compressible turbulent flows, including subgrid-scale (SGS) and viscosity terms, are investigated. After selecting a suitable definition for large-scale helicity, we confirm the existence of the dual channel of SGS and viscosity terms of large-scale helicity governing equations and theoretically prove that no dual pressure term channel exists. The second channel of the SGS and viscosity terms also consists of two terms, which originate from the rotation of the SGS stress and the baroclinic of the velocity and density gradients, respectively. The identical relationship of the ensemble averages of the dual channel of SGS and viscosity terms can be theoretically and numerically confirmed, whereas their second channel which is associated with shocklets is more intermittent. For the SGS term, the compression regions are dominant in contrast to the expansion regions, and the strain regions are dominant in contrast to the rotation regions in the inertial scale range. The viscous dissipation mechanism of large-scale helicity differs from that of large-scale kinetic energy. It is dominated by the first channel on the inside of the vortex structure and by the second channel on the outside. The further decompositions of the second channel of the SGS and viscosity terms provide a possible mechanism for the inverse helicity transfer. This means that expansion motions promote inverse helicity transfer through the second terms of their second channels.\",\"PeriodicalId\":20160,\"journal\":{\"name\":\"Physical Review Fluids\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.5000,\"publicationDate\":\"2024-09-04\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Physical Review Fluids\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://doi.org/10.1103/physrevfluids.9.094603\",\"RegionNum\":3,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"PHYSICS, FLUIDS & PLASMAS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Physical Review Fluids","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1103/physrevfluids.9.094603","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, FLUIDS & PLASMAS","Score":null,"Total":0}
The dual-channel characteristics of large-scale helicity transfer in compressible turbulent flows, including subgrid-scale (SGS) and viscosity terms, are investigated. After selecting a suitable definition for large-scale helicity, we confirm the existence of the dual channel of SGS and viscosity terms of large-scale helicity governing equations and theoretically prove that no dual pressure term channel exists. The second channel of the SGS and viscosity terms also consists of two terms, which originate from the rotation of the SGS stress and the baroclinic of the velocity and density gradients, respectively. The identical relationship of the ensemble averages of the dual channel of SGS and viscosity terms can be theoretically and numerically confirmed, whereas their second channel which is associated with shocklets is more intermittent. For the SGS term, the compression regions are dominant in contrast to the expansion regions, and the strain regions are dominant in contrast to the rotation regions in the inertial scale range. The viscous dissipation mechanism of large-scale helicity differs from that of large-scale kinetic energy. It is dominated by the first channel on the inside of the vortex structure and by the second channel on the outside. The further decompositions of the second channel of the SGS and viscosity terms provide a possible mechanism for the inverse helicity transfer. This means that expansion motions promote inverse helicity transfer through the second terms of their second channels.
期刊介绍:
Physical Review Fluids is APS’s newest online-only journal dedicated to publishing innovative research that will significantly advance the fundamental understanding of fluid dynamics. Physical Review Fluids expands the scope of the APS journals to include additional areas of fluid dynamics research, complements the existing Physical Review collection, and maintains the same quality and reputation that authors and subscribers expect from APS. The journal is published with the endorsement of the APS Division of Fluid Dynamics.