{"title":"主动涡流发生器诱导流场的实验评估","authors":"","doi":"10.1016/j.expthermflusci.2024.111280","DOIUrl":null,"url":null,"abstract":"<div><p>This investigation examined the flow field generated by a ramp-shaped vortex generator (VG) that underwent active oscillation within a laminar boundary layer. The oscillations were applied through a servomotor, which pivoted the VG around its leading edge. The study evaluated the influence of varying the maximum VG height during the oscillations (<em>h</em>), actuation frequency (<em>f</em>), and the waveform governing the periodic oscillation of the VG. Planar particle image velocimetry (PIV) measurements were conducted to estimate flow mixing and the drag induced by the VG. The height-based Reynolds number (<em>Re</em><sub>h</sub>) ranged from 300 to 600, and the chord-based Strouhal number (<em>St</em><sub>c</sub>) for the oscillations varied from 0.67 to 3.33. The findings of the study indicate that active VGs lead to a greater wall-normal transport of streamwise momentum and result in lower drag compared to static VGs. Furthermore, increasing <em>h</em> results in larger momentum transport and drag of the active VGs. The investigation also revealed that the highest momentum transport and drag occurred when <em>f</em> was close to the instability frequency of the shear layer. The results show the potential of active VGs for separation control under various flow conditions.</p></div>","PeriodicalId":12294,"journal":{"name":"Experimental Thermal and Fluid Science","volume":null,"pages":null},"PeriodicalIF":2.8000,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0894177724001493/pdfft?md5=691b324f0c38c36f39003b7e1af296fb&pid=1-s2.0-S0894177724001493-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Experimental evaluation of the flow field induced by an active vortex generator\",\"authors\":\"\",\"doi\":\"10.1016/j.expthermflusci.2024.111280\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>This investigation examined the flow field generated by a ramp-shaped vortex generator (VG) that underwent active oscillation within a laminar boundary layer. The oscillations were applied through a servomotor, which pivoted the VG around its leading edge. The study evaluated the influence of varying the maximum VG height during the oscillations (<em>h</em>), actuation frequency (<em>f</em>), and the waveform governing the periodic oscillation of the VG. Planar particle image velocimetry (PIV) measurements were conducted to estimate flow mixing and the drag induced by the VG. The height-based Reynolds number (<em>Re</em><sub>h</sub>) ranged from 300 to 600, and the chord-based Strouhal number (<em>St</em><sub>c</sub>) for the oscillations varied from 0.67 to 3.33. The findings of the study indicate that active VGs lead to a greater wall-normal transport of streamwise momentum and result in lower drag compared to static VGs. Furthermore, increasing <em>h</em> results in larger momentum transport and drag of the active VGs. The investigation also revealed that the highest momentum transport and drag occurred when <em>f</em> was close to the instability frequency of the shear layer. The results show the potential of active VGs for separation control under various flow conditions.</p></div>\",\"PeriodicalId\":12294,\"journal\":{\"name\":\"Experimental Thermal and Fluid Science\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.8000,\"publicationDate\":\"2024-08-05\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://www.sciencedirect.com/science/article/pii/S0894177724001493/pdfft?md5=691b324f0c38c36f39003b7e1af296fb&pid=1-s2.0-S0894177724001493-main.pdf\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Experimental Thermal and Fluid Science\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0894177724001493\",\"RegionNum\":2,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"ENGINEERING, MECHANICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Experimental Thermal and Fluid Science","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0894177724001493","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, MECHANICAL","Score":null,"Total":0}
Experimental evaluation of the flow field induced by an active vortex generator
This investigation examined the flow field generated by a ramp-shaped vortex generator (VG) that underwent active oscillation within a laminar boundary layer. The oscillations were applied through a servomotor, which pivoted the VG around its leading edge. The study evaluated the influence of varying the maximum VG height during the oscillations (h), actuation frequency (f), and the waveform governing the periodic oscillation of the VG. Planar particle image velocimetry (PIV) measurements were conducted to estimate flow mixing and the drag induced by the VG. The height-based Reynolds number (Reh) ranged from 300 to 600, and the chord-based Strouhal number (Stc) for the oscillations varied from 0.67 to 3.33. The findings of the study indicate that active VGs lead to a greater wall-normal transport of streamwise momentum and result in lower drag compared to static VGs. Furthermore, increasing h results in larger momentum transport and drag of the active VGs. The investigation also revealed that the highest momentum transport and drag occurred when f was close to the instability frequency of the shear layer. The results show the potential of active VGs for separation control under various flow conditions.
期刊介绍:
Experimental Thermal and Fluid Science provides a forum for research emphasizing experimental work that enhances fundamental understanding of heat transfer, thermodynamics, and fluid mechanics. In addition to the principal areas of research, the journal covers research results in related fields, including combined heat and mass transfer, flows with phase transition, micro- and nano-scale systems, multiphase flow, combustion, radiative transfer, porous media, cryogenics, turbulence, and novel experimental techniques.