In this study, experiments were performed to measure the thickness of the liquid film formed between the heating surface and the vapor bubble with the laser extinction method for the gap size of 0.5, 0.3 and 0.15mm.Water, toluene and HFE7200 were used as test fluids. It was found that the gap size and bubble forefront velocity determined the initial thickness of microlayer no matter of the kind of testing liquid. Vapor bubble generated by boiling in the present mini-gap grows exponentially due to the rapid evaporation of the thin liquid layer, which makes the phenomena highly transient as opposed to the steady situations considered before. Based on the experimental data and scaling arguments a non-dimensional correlation in terms of capillary number and Bond number is proposed.
{"title":"Formation characteristics of microlayer between elongated bubble and heating surface in mini-gap boiling system","authors":"Yaohua Zilang, Y. Utaka","doi":"10.1299/KIKAIB.78.1572","DOIUrl":"https://doi.org/10.1299/KIKAIB.78.1572","url":null,"abstract":"In this study, experiments were performed to measure the thickness of the liquid film formed between the heating surface and the vapor bubble with the laser extinction method for the gap size of 0.5, 0.3 and 0.15mm.Water, toluene and HFE7200 were used as test fluids. It was found that the gap size and bubble forefront velocity determined the initial thickness of microlayer no matter of the kind of testing liquid. Vapor bubble generated by boiling in the present mini-gap grows exponentially due to the rapid evaporation of the thin liquid layer, which makes the phenomena highly transient as opposed to the steady situations considered before. Based on the experimental data and scaling arguments a non-dimensional correlation in terms of capillary number and Bond number is proposed.","PeriodicalId":331123,"journal":{"name":"Transactions of the Japan Society of Mechanical Engineers. B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126679361","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}
To analyze large-scale fracture mechanics problems effectively, we apply the partitioned iterative coupling algorithm which has been successfully utilized for multi-physics coupling problems. In the algorithm, the analysis domain is first decomposed into two domains. The one domain contains a crack, while the other does not. The two domains are analyzed separately and alternately with assumed boundary conditions on the boundary between the two domains. By updating the assumed boundary conditions repeatedly, the converged solution is finally obtained. In crack propagation analyses, this coupling iteration is performed at each crack propagation step. In a numerical experiment of an edged crack tension plate model of 1.96 million degrees of freedom, stress intensity factors are computed 4.52 times faster than using a conventional finite element method. This is because, in the partitioned iterative coupling algorithm, the stiffness matrix on the domain far from the crack is constant through the whole crack propagation analysis.
{"title":"Large-scale fracture mechanics analysis using partitioned iterative coupling algorithm","authors":"Y. Yusa, S. Kataoka, H. Kawai, S. Yoshimura","doi":"10.1299/KIKAIA.78.966","DOIUrl":"https://doi.org/10.1299/KIKAIA.78.966","url":null,"abstract":"To analyze large-scale fracture mechanics problems effectively, we apply the partitioned iterative coupling algorithm which has been successfully utilized for multi-physics coupling problems. In the algorithm, the analysis domain is first decomposed into two domains. The one domain contains a crack, while the other does not. The two domains are analyzed separately and alternately with assumed boundary conditions on the boundary between the two domains. By updating the assumed boundary conditions repeatedly, the converged solution is finally obtained. In crack propagation analyses, this coupling iteration is performed at each crack propagation step. In a numerical experiment of an edged crack tension plate model of 1.96 million degrees of freedom, stress intensity factors are computed 4.52 times faster than using a conventional finite element method. This is because, in the partitioned iterative coupling algorithm, the stiffness matrix on the domain far from the crack is constant through the whole crack propagation analysis.","PeriodicalId":331123,"journal":{"name":"Transactions of the Japan Society of Mechanical Engineers. B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122621914","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. Kameya, Y. Matsuda, Y. Egami, H. Yamaguchi, T. Niimi
A novel combined Pressure-/Temperature-Sensitive Paint (PSP/TSP) sensor, which consists of dot arrays of PSP and TSP, has been developed for simultaneous measurements of pressure and temperature on a solid surface. Conventional combined PSP/TSP sensors suffer from the photodegradation caused by interaction between PSP and TSP luminophores. In the proposed sensor, dot arrays of PSP and TSP were separately arranged for avoiding the interaction. The PSP and TSP dots were made of PtTFPP and CdSe/ZnS, respectively, so that the luminescences from each dot array could be separately detected by optical filters. We investigated fundamental properties of the dot array sensor: photostability, pressure sensitivity and temperature sensitivity. As a result, the photodegradation was not observed in the dot array sensor. It was also shown that PtTFPP dot array had the pressure sensitivity of 0.53%/kPa, and CdSe/ZnS dot array had the temperature sensitivity of -0.61%/K, which were almost the same sensitivities as conventional PSPs and TSPs. Therefore, the proposed sensor will be a preferable sensor for the simultaneous measurement of pressure and temperature.
{"title":"Combined pressure-/temperature-sensitive paint arranged in dot array","authors":"T. Kameya, Y. Matsuda, Y. Egami, H. Yamaguchi, T. Niimi","doi":"10.1299/KIKAIB.78.1327","DOIUrl":"https://doi.org/10.1299/KIKAIB.78.1327","url":null,"abstract":"A novel combined Pressure-/Temperature-Sensitive Paint (PSP/TSP) sensor, which consists of dot arrays of PSP and TSP, has been developed for simultaneous measurements of pressure and temperature on a solid surface. Conventional combined PSP/TSP sensors suffer from the photodegradation caused by interaction between PSP and TSP luminophores. In the proposed sensor, dot arrays of PSP and TSP were separately arranged for avoiding the interaction. The PSP and TSP dots were made of PtTFPP and CdSe/ZnS, respectively, so that the luminescences from each dot array could be separately detected by optical filters. We investigated fundamental properties of the dot array sensor: photostability, pressure sensitivity and temperature sensitivity. As a result, the photodegradation was not observed in the dot array sensor. It was also shown that PtTFPP dot array had the pressure sensitivity of 0.53%/kPa, and CdSe/ZnS dot array had the temperature sensitivity of -0.61%/K, which were almost the same sensitivities as conventional PSPs and TSPs. Therefore, the proposed sensor will be a preferable sensor for the simultaneous measurement of pressure and temperature.","PeriodicalId":331123,"journal":{"name":"Transactions of the Japan Society of Mechanical Engineers. B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116465768","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. Handa, D. Ono, Hiroyuki Kubota, Hiroaki Miyachi
The oscillatory behaviors in a supersonic cavity flow are visualized by LIF (Laser-Induced Fluorescence) and schlieren methods. In the LIF method, an argon-ion laser is used as a light source to excite the iodine molecules seeded into the working gas. The iodine fluorescence, whose intensity is known to be a function of temperature, is detected by the photomultiplier. The pressure oscillation on the bottom wall of the cavity is also measured simultaneously with the fluorescence detection. The phase of fluorescence-intensity oscillation is corrected on the basis of the cavity-bottom pressure oscillation and the correction is performed at every fluorescence detection point. As a result, the temperature oscillations inside and outside the cavity are qualitatively visualized in two-dimensional sense. In the schlieren method, the light source is controlled so as to flash responding to a specific phase of the periodic pressure signal and the oscillatory motion of the shear layer developing along the cavity span is captured. By carefully observing both of the visualization results, the relation between the temperature oscillation and shear-layer motion is clarified.
{"title":"Visualization of an oscillatory supersonic cavity flow using lif and schlieren methods","authors":"T. Handa, D. Ono, Hiroyuki Kubota, Hiroaki Miyachi","doi":"10.1299/KIKAIB.78.1318","DOIUrl":"https://doi.org/10.1299/KIKAIB.78.1318","url":null,"abstract":"The oscillatory behaviors in a supersonic cavity flow are visualized by LIF (Laser-Induced Fluorescence) and schlieren methods. In the LIF method, an argon-ion laser is used as a light source to excite the iodine molecules seeded into the working gas. The iodine fluorescence, whose intensity is known to be a function of temperature, is detected by the photomultiplier. The pressure oscillation on the bottom wall of the cavity is also measured simultaneously with the fluorescence detection. The phase of fluorescence-intensity oscillation is corrected on the basis of the cavity-bottom pressure oscillation and the correction is performed at every fluorescence detection point. As a result, the temperature oscillations inside and outside the cavity are qualitatively visualized in two-dimensional sense. In the schlieren method, the light source is controlled so as to flash responding to a specific phase of the periodic pressure signal and the oscillatory motion of the shear layer developing along the cavity span is captured. By carefully observing both of the visualization results, the relation between the temperature oscillation and shear-layer motion is clarified.","PeriodicalId":331123,"journal":{"name":"Transactions of the Japan Society of Mechanical Engineers. B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126429892","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":"常温水に対する多重プロセス型キャビテーションモデルの構築および検証（初生/崩壊および合体/分裂の導入）","authors":"伸一 津田, 直樹 谷, 伸宏 山西","doi":"10.1299/KIKAIB.78.1165","DOIUrl":"https://doi.org/10.1299/KIKAIB.78.1165","url":null,"abstract":"","PeriodicalId":331123,"journal":{"name":"Transactions of the Japan Society of Mechanical Engineers. B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130085668","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}
Pressure-sensitive paint (PSP) is a useful measurement technique to non-intrusively obtain a pressure distribution on a surface. Recently, PSP has been applied to micro gas flow measurements; thus the spatial resolution of PSP measurement is very important to assess the measured pressure. However, the spatial resolution has not been discussed except by Moshasrov et al. (1997). They evaluated the spatial resolution corresponds to a pressure jump on a PSP surface with consideration of an oxygen concentration distribution in a PSP layer. In this study, we have discussed the spatial resolution by numerically solving the two-dimensional di ffuse equation with pressure slope as a boundary condition on a surface of PSP. The result with pressure jump, as a limiting case of pressure slope, showed good agreement with the result reported by Moshasrov et al. (1997). Moreover, it is theoretically clarified that the pressure variation with a spatial distance of lager than 8.5 times of the thickness of PSP can be completely measured by PSP without the e ffec of oxygen diffusion in a PSP layer.
{"title":"A discusion of spatial resolution of pressure-sensitive paint","authors":"Y. Matsuda, H. Yamaguchi, Y. Egami, T. Niimi","doi":"10.1299/KIKAIB.78.1260","DOIUrl":"https://doi.org/10.1299/KIKAIB.78.1260","url":null,"abstract":"Pressure-sensitive paint (PSP) is a useful measurement technique to non-intrusively obtain a pressure distribution on a surface. Recently, PSP has been applied to micro gas flow measurements; thus the spatial resolution of PSP measurement is very important to assess the measured pressure. However, the spatial resolution has not been discussed except by Moshasrov et al. (1997). They evaluated the spatial resolution corresponds to a pressure jump on a PSP surface with consideration of an oxygen concentration distribution in a PSP layer. In this study, we have discussed the spatial resolution by numerically solving the two-dimensional di ffuse equation with pressure slope as a boundary condition on a surface of PSP. The result with pressure jump, as a limiting case of pressure slope, showed good agreement with the result reported by Moshasrov et al. (1997). Moreover, it is theoretically clarified that the pressure variation with a spatial distance of lager than 8.5 times of the thickness of PSP can be completely measured by PSP without the e ffec of oxygen diffusion in a PSP layer.","PeriodicalId":331123,"journal":{"name":"Transactions of the Japan Society of Mechanical Engineers. B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131296100","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}
Extinction and flame structure of lean premixed and diffusion combined flames formed in a counter flow are investigated experimentally and numerically. The extinction limits can be divided into two regions. One is a diffusion flame dominant extinction region (DF-DE) in which equivalence ratio of LPF side (φL) at extinction limit is decreasing linearly with increasing fuel concentration of DF side (χU). The other is a lean premixed flame dominant extinction region (LPF-DE) in which effect of χU on extinction φL is increasing with increasing χU. In these two regions, the flame structures and its φL dependence are different greatly. In the DF-DE, the temperature has symmetrical profile regardless of φL and the temperature peak is located near DF. Since DF has higher temperature than LPF, LPF is thermally supported than DF. Temperature gradients between two reaction zones are decreasing with increasing φL, while laminar burning velocity (SL) and burnt gas width (WB) are constant regardless of φL. On the other hand, in the LPF-DE, the temperature has asymmetrical profile and the temperature peak leans to the LPF side. That is, the temperature gradient of LPF side is very steep compared with the DF side. Since LPF has higher temperature than DF, DF is thermally supported than LPF. Temperature gradients between two reaction zones are constant regardless of φL, while SL and WB are increasing with increasing φL.
{"title":"Flame structure of lean premixed and diffusion combined flames near extinction limit","authors":"T. Kawanami, Y. Yahagi","doi":"10.1299/KIKAIB.78.1118","DOIUrl":"https://doi.org/10.1299/KIKAIB.78.1118","url":null,"abstract":"Extinction and flame structure of lean premixed and diffusion combined flames formed in a counter flow are investigated experimentally and numerically. The extinction limits can be divided into two regions. One is a diffusion flame dominant extinction region (DF-DE) in which equivalence ratio of LPF side (φL) at extinction limit is decreasing linearly with increasing fuel concentration of DF side (χU). The other is a lean premixed flame dominant extinction region (LPF-DE) in which effect of χU on extinction φL is increasing with increasing χU. In these two regions, the flame structures and its φL dependence are different greatly. In the DF-DE, the temperature has symmetrical profile regardless of φL and the temperature peak is located near DF. Since DF has higher temperature than LPF, LPF is thermally supported than DF. Temperature gradients between two reaction zones are decreasing with increasing φL, while laminar burning velocity (SL) and burnt gas width (WB) are constant regardless of φL. On the other hand, in the LPF-DE, the temperature has asymmetrical profile and the temperature peak leans to the LPF side. That is, the temperature gradient of LPF side is very steep compared with the DF side. Since LPF has higher temperature than DF, DF is thermally supported than LPF. Temperature gradients between two reaction zones are constant regardless of φL, while SL and WB are increasing with increasing φL.","PeriodicalId":331123,"journal":{"name":"Transactions of the Japan Society of Mechanical Engineers. B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126834273","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}
Local active noise control systems create a zone of quiet around a physical error sensor location. The zone of quiet is generally small, and as such, the physical error sensor is placed at the desired location of sound attenuation, which is usually inconvenient. Virtual sensing algorithms have been developed to aim for creating the zone of quiet at virtual sensor location that is remote from the physical error sensor. However the sound attenuation of the traditional virtual sensing algorithms worsen by change of primary source location that alter the transfer characteristics between a physical sensor and a virtual sensor. This paper presents a method to maintain the sound attenuation at a virtual location in change of sound incident direction of primary source and show positive results of experiments in an anechoic room. The proposed method estimate sound incident direction of primary source to use signals of two microphones and be able to switch between an appropriate filter that is measured in preliminarily identification stage to estimate signal at virtual sensor location.
{"title":"Active noise control using a virtual sensing algorithm with incident direction information of noise","authors":"Yosuke Koba, Daisuke Kondo, S. Kijimoto","doi":"10.1299/KIKAIB.78.954","DOIUrl":"https://doi.org/10.1299/KIKAIB.78.954","url":null,"abstract":"Local active noise control systems create a zone of quiet around a physical error sensor location. The zone of quiet is generally small, and as such, the physical error sensor is placed at the desired location of sound attenuation, which is usually inconvenient. Virtual sensing algorithms have been developed to aim for creating the zone of quiet at virtual sensor location that is remote from the physical error sensor. However the sound attenuation of the traditional virtual sensing algorithms worsen by change of primary source location that alter the transfer characteristics between a physical sensor and a virtual sensor. This paper presents a method to maintain the sound attenuation at a virtual location in change of sound incident direction of primary source and show positive results of experiments in an anechoic room. The proposed method estimate sound incident direction of primary source to use signals of two microphones and be able to switch between an appropriate filter that is measured in preliminarily identification stage to estimate signal at virtual sensor location.","PeriodicalId":331123,"journal":{"name":"Transactions of the Japan Society of Mechanical Engineers. B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131520521","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}
For understanding of film cooling flow fields on a gas turbine blade, this paper reports on a series of large-eddy simulations of an inclined round jet issuing into a crossflow. Simulations were performed at four blowing ratio conditions, BR=0.1, 0.5, 0.7 and 1.0 and Reynolds number, Re=15,300, based on crossflow velocity and film cooling hole diameter. Results showed that cooling jet flow structure drastically changed with blowing ratio. A pair of rear vortex and hairpin vortex were observed for BR=0.1. A periodic ejection of horseshoe vortex, a pair of hanging vortex, a pair of rear vortex and hairpin vortex were observed for BR=0.5. Similar vortical structures to BR=0.5 were observed for BR=0.7 although horseshoe vortex remained at a leading edge of the hole exit. For BR=1.0, in addition to the former mentioned vortices, spanwise rollers and vertical streaks were observed on an upstream edge of the jet. It was, consequently understood that the ubiquitous counter-rotating vortex pair which can be defined in the time-averaged flow field was actually originated in the different vortical structures with varying BR conditions.
{"title":"Large eddy simulation of inclined round jet issuing into cross-flow","authors":"E. Sakai, Toshihiko Takahashi, H. Watanabe","doi":"10.1299/KIKAIB.78.1107","DOIUrl":"https://doi.org/10.1299/KIKAIB.78.1107","url":null,"abstract":"For understanding of film cooling flow fields on a gas turbine blade, this paper reports on a series of large-eddy simulations of an inclined round jet issuing into a crossflow. Simulations were performed at four blowing ratio conditions, BR=0.1, 0.5, 0.7 and 1.0 and Reynolds number, Re=15,300, based on crossflow velocity and film cooling hole diameter. Results showed that cooling jet flow structure drastically changed with blowing ratio. A pair of rear vortex and hairpin vortex were observed for BR=0.1. A periodic ejection of horseshoe vortex, a pair of hanging vortex, a pair of rear vortex and hairpin vortex were observed for BR=0.5. Similar vortical structures to BR=0.5 were observed for BR=0.7 although horseshoe vortex remained at a leading edge of the hole exit. For BR=1.0, in addition to the former mentioned vortices, spanwise rollers and vertical streaks were observed on an upstream edge of the jet. It was, consequently understood that the ubiquitous counter-rotating vortex pair which can be defined in the time-averaged flow field was actually originated in the different vortical structures with varying BR conditions.","PeriodicalId":331123,"journal":{"name":"Transactions of the Japan Society of Mechanical Engineers. B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130754724","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}
The aim of this study is to investigate on the flow behavior in the wake behind a circular cylinder by induced jet using dielectric barrier discharge (DBD) plasma. The plasma was created using a wave form with bipolar voltage of 4 kVpp and frequency of 10 kHz, and the plasma actuators were mounted on the circular cylinder. The forward and backward jets for the main flow direction were induced by electrode arrangements of the plasma actuators. The flow field was visualized using a high-speed video camera, and the streamwise and vertical velocities ware calculated by dynamics PIV method at Reynolds number of 1.0×103. We discussed that the vortex motion around the cylinder, Reynolds stress profiles and the half width of wakes by the forward and backward jets. Also, the characteristic frequency of vortex shedding was confirmed from the continuous photographs.
{"title":"プラズマアクチュエータによる円柱流れの制御に関する研究（第二報：後流構造の流れの可視化）","authors":"俊輔 山田, 仁志 石川, 武彦 瀬川","doi":"10.1299/KIKAIB.78.734","DOIUrl":"https://doi.org/10.1299/KIKAIB.78.734","url":null,"abstract":"The aim of this study is to investigate on the flow behavior in the wake behind a circular cylinder by induced jet using dielectric barrier discharge (DBD) plasma. The plasma was created using a wave form with bipolar voltage of 4 kVpp and frequency of 10 kHz, and the plasma actuators were mounted on the circular cylinder. The forward and backward jets for the main flow direction were induced by electrode arrangements of the plasma actuators. The flow field was visualized using a high-speed video camera, and the streamwise and vertical velocities ware calculated by dynamics PIV method at Reynolds number of 1.0×103. We discussed that the vortex motion around the cylinder, Reynolds stress profiles and the half width of wakes by the forward and backward jets. Also, the characteristic frequency of vortex shedding was confirmed from the continuous photographs.","PeriodicalId":331123,"journal":{"name":"Transactions of the Japan Society of Mechanical Engineers. B","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116420032","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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