Direct numerical simulation of turbulent channel flow at Reτ = 110 ~ 650 was made in order to evaluate feedback control algorithms for reducing skin friction. The energy efficiency of the v-control and suboptimal control is deteriorated with increasing the Reynolds number, but it becomes almost constant above Reτ = 300. It is found through the Karhunen-Loeve decomposition of the turbulent fluctuations that the structures having large contribution to the turbulent kinetic energy are of large scale, whilst the structures having large contribution to the wall shear stress fluctuation are scaled with viscous units and accompanied with the quasi-streamwise vortices near the wall. The KL modes are divided into groups depending on the wall elevation of the structures, and the nonlinear interaction between those structures are examined. It is indicated that the interaction effect is larger at higher Reynolds numbers, but the near-wall vortices are not much affected by the interaction with the large-scale outer structures.
{"title":"Effect of nonlinear interaction on feedback control of wall turbulence","authors":"K. Iwamoto, Yuji Suzuki, N. Kasagi","doi":"10.1615/tsfp2.1660","DOIUrl":"https://doi.org/10.1615/tsfp2.1660","url":null,"abstract":"Direct numerical simulation of turbulent channel flow at Reτ = 110 ~ 650 was made in order to evaluate feedback control algorithms for reducing skin friction. The energy efficiency of the v-control and suboptimal control is deteriorated with increasing the Reynolds number, but it becomes almost constant above Reτ = 300. It is found through the Karhunen-Loeve decomposition of the turbulent fluctuations that the structures having large contribution to the turbulent kinetic energy are of large scale, whilst the structures having large contribution to the wall shear stress fluctuation are scaled with viscous units and accompanied with the quasi-streamwise vortices near the wall. The KL modes are divided into groups depending on the wall elevation of the structures, and the nonlinear interaction between those structures are examined. It is indicated that the interaction effect is larger at higher Reynolds numbers, but the near-wall vortices are not much affected by the interaction with the large-scale outer structures.","PeriodicalId":438618,"journal":{"name":"Proceeding of Second Symposium on Turbulence and Shear Flow Phenomena","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127803760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ACTIVE CONTROL OF WALL TURBULENCE BY AN ACTUATOR ARRAY PRODUCING SPANWISE PERTURBATIONS","authors":"T. Segawa, Y. Kawaguchi, Y. Kikushima, H. Yoshida","doi":"10.1615/tsfp2.310","DOIUrl":"https://doi.org/10.1615/tsfp2.310","url":null,"abstract":"","PeriodicalId":438618,"journal":{"name":"Proceeding of Second Symposium on Turbulence and Shear Flow Phenomena","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117279615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Kunugi, Yoshinobu Yamamoto, S. Satake, A. Serizawa
{"title":"RELATIONSHIPS BETWEEN COHERENT STRUCTURE AND TURBULENT STATISTICS STRUCTURE IN WIND-DRIVEN TURBULENT FLOW, VIA DNS","authors":"T. Kunugi, Yoshinobu Yamamoto, S. Satake, A. Serizawa","doi":"10.1615/tsfp2.1750","DOIUrl":"https://doi.org/10.1615/tsfp2.1750","url":null,"abstract":"","PeriodicalId":438618,"journal":{"name":"Proceeding of Second Symposium on Turbulence and Shear Flow Phenomena","volume":"474-476 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116770531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"LDA MEASUREMENTS IN TURBULENT BOUNDARY LAYERS WITH ZERO PRESSURE GRADIENT","authors":"G. Johansson, L. Castillo","doi":"10.1615/tsfp2.760","DOIUrl":"https://doi.org/10.1615/tsfp2.760","url":null,"abstract":"","PeriodicalId":438618,"journal":{"name":"Proceeding of Second Symposium on Turbulence and Shear Flow Phenomena","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127177410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"DYNAMICS AND ANALYSIS OF VORTEX-FLAME INTERACTION IN SWIRLING COMBUSTION FLOWS","authors":"C. Stone, S. Menon","doi":"10.1615/tsfp2.1550","DOIUrl":"https://doi.org/10.1615/tsfp2.1550","url":null,"abstract":"","PeriodicalId":438618,"journal":{"name":"Proceeding of Second Symposium on Turbulence and Shear Flow Phenomena","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125311870","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1088/1468-5248/3/1/008
L. Falcomer, V. Armenio
In this paper, large-eddy simulations of a turbulent channel flow with longitudinal, large-amplitude, ridges are carried out. This flow exhibits large secondary recirculations in the cross-stream plane that need to be properly simulated in order to evaluate with enough accuracy the spanwise distribution of the primary as well as the secondary wall stress. Available DNS data at low Reynolds number as well as data from an experimental investigation at a moderate Reynolds number are matched. Our LES results agree satisfactorily with the DNS data at Re τ = 140, and with the experimental data at Re τ = 580. This investigation shows that the intensity and topology of the secondary flow is dependent on the Reynolds number of the flow. Unlike previous investigations, the present results have also shown that when the Reynolds number is large enough near-wall, small and intense cellular flows appear, which may produce localized secondary wall stresses. The analysis of the coherent structures that evolve in the buff...
{"title":"LARGE EDDY SIMULATION OF SECONDARY FLOWS OVER LONGITUDINALLY-RIDGED WALLS","authors":"L. Falcomer, V. Armenio","doi":"10.1088/1468-5248/3/1/008","DOIUrl":"https://doi.org/10.1088/1468-5248/3/1/008","url":null,"abstract":"In this paper, large-eddy simulations of a turbulent channel flow with longitudinal, large-amplitude, ridges are carried out. This flow exhibits large secondary recirculations in the cross-stream plane that need to be properly simulated in order to evaluate with enough accuracy the spanwise distribution of the primary as well as the secondary wall stress. Available DNS data at low Reynolds number as well as data from an experimental investigation at a moderate Reynolds number are matched. Our LES results agree satisfactorily with the DNS data at Re τ = 140, and with the experimental data at Re τ = 580. This investigation shows that the intensity and topology of the secondary flow is dependent on the Reynolds number of the flow. Unlike previous investigations, the present results have also shown that when the Reynolds number is large enough near-wall, small and intense cellular flows appear, which may produce localized secondary wall stresses. The analysis of the coherent structures that evolve in the buff...","PeriodicalId":438618,"journal":{"name":"Proceeding of Second Symposium on Turbulence and Shear Flow Phenomena","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126916234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"DIRECT STUDY OF THE CONSTITUTIVE EQUATION FOR TURBULENT NEAR-WALL FLOWS USING DNS DATA","authors":"F. Schmitt, C. Hirsch","doi":"10.1615/tsfp2.1080","DOIUrl":"https://doi.org/10.1615/tsfp2.1080","url":null,"abstract":"","PeriodicalId":438618,"journal":{"name":"Proceeding of Second Symposium on Turbulence and Shear Flow Phenomena","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126974430","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"ON THE DECAY OF SHEARLESS WALL BOUNDED TURBULENCE","authors":"J. Bertoglio, H. Touil, L. Shao","doi":"10.1615/tsfp2.2090","DOIUrl":"https://doi.org/10.1615/tsfp2.2090","url":null,"abstract":"","PeriodicalId":438618,"journal":{"name":"Proceeding of Second Symposium on Turbulence and Shear Flow Phenomena","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115106055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Numerical Prediction of Liquid-Solid Turbulent Flows on Moving Boundaries with ALE Method","authors":"S. Ushijima, I. Nezu","doi":"10.1615/tsfp2.470","DOIUrl":"https://doi.org/10.1615/tsfp2.470","url":null,"abstract":"","PeriodicalId":438618,"journal":{"name":"Proceeding of Second Symposium on Turbulence and Shear Flow Phenomena","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127480499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A CONJECTURE: TURBULENCE SUBJECTED TO CYCLIC STRAIN ALWAYS DECAYS","authors":"I. Hadzic, K. Hanjalic, D. Laurence","doi":"10.1615/tsfp2.370","DOIUrl":"https://doi.org/10.1615/tsfp2.370","url":null,"abstract":"","PeriodicalId":438618,"journal":{"name":"Proceeding of Second Symposium on Turbulence and Shear Flow Phenomena","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125091278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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