Proceeding of Tenth International Symposium on Turbulence and Shear Flow Phenomena最新文献

{"title":"STATE DETECTION AND HYBRID SIMULATION OF BIOMEDICAL FLOWS","authors":"László Daróczy, A. Abdelsamie, G. Janiga, D. Thévenin","doi":"10.1615/tsfp10.600","DOIUrl":"https://doi.org/10.1615/tsfp10.600","url":null,"abstract":"","PeriodicalId":266791,"journal":{"name":"Proceeding of Tenth International Symposium on Turbulence and Shear Flow Phenomena","volume":"300 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":"123749092","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":"INFLUENCE OF SENSOR LOCATION IN REMOTE-SENSOR BASED FLOW ESTIMATION","authors":"Annah Amani, R. Martinuzzi","doi":"10.1615/tsfp10.860","DOIUrl":"https://doi.org/10.1615/tsfp10.860","url":null,"abstract":"","PeriodicalId":266791,"journal":{"name":"Proceeding of Tenth International Symposium on Turbulence and Shear Flow Phenomena","volume":"302 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":"132833734","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":"THE FLUCTUATING VELOCITY FIELD ABOVE THE FREE END OF A SURFACEMOUNTED FINITE-HEIGHT SQUARE PRISM","authors":"R. Chakravarty, N. Rostamy, D. Bergstrom, D. Sumner","doi":"10.1615/tsfp10.750","DOIUrl":"https://doi.org/10.1615/tsfp10.750","url":null,"abstract":"This study investigates the features of the fluctuating velocity field above the free end of a surface-mounted finite-height square prism, at a Reynolds number of Re = 4.2×10, using two state-of-the-art post-processing methodologies, namely Proper Orthogonal Decomposition (POD) and the swirling strength criterion. Instantaneous velocity measurements were obtained from Particle Image Velocimetry (PIV) experiments conducted in a low-speed wind tunnel for the flow over finite square prisms of aspect ratios AR = 9, 7, 5 and 3 (AR = H/D where H is the prism height and D is the prism width). The prisms were immersed in a thin, turbulent boundary layer with a dimensionless thickness of δ/D = 1.6. The Reynolds number based on the freestream velocity U∞ was Re = 4.2×10. POD modes were used to extract the dominant flow features, which revealed a pair of shear sub-layers above the free end, flow entrainment from the freestream above, as well as several vortex structures in the mean shear flow region. At lower aspect ratios, the shear layers become more pronounced. Combined with the swirling strength results, this represents evidence of Kelvin-Helmholtz instabilities within the shear layer region. These instabilities increase moving away from the vertical symmetry plane. Some structures in the near wake above and behind the prism trailing edge are also seen due to the interactions of the reverse flow downstream with the downwash flow.","PeriodicalId":266791,"journal":{"name":"Proceeding of Tenth International Symposium on Turbulence and Shear Flow Phenomena","volume":"8 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":"134259450","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":"Merging of coherent structures in a separation bubble","authors":"J. Kurelek, S. Yarusevych","doi":"10.1615/tsfp10.540","DOIUrl":"https://doi.org/10.1615/tsfp10.540","url":null,"abstract":"","PeriodicalId":266791,"journal":{"name":"Proceeding of Tenth International Symposium on Turbulence and Shear Flow Phenomena","volume":"10 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":"133874052","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":"UNSTEADY AERODYNAMIC EFFECTS IN PITCHING AIRFOILS STUDIED THROUGH LARGE-EDDY SIMULATIONS","authors":"P. Negi, R. Vinuesa, P. Schlatter, A. Hanifi, D. Henningson","doi":"10.1615/tsfp10.200","DOIUrl":"https://doi.org/10.1615/tsfp10.200","url":null,"abstract":"Wall-resolved large-eddy simulations (LES) are utilized to investigate the flow-physics of an airfoil undergoing pitch oscillations. A relaxation-term (RT) based filtering procedure is employed to ...","PeriodicalId":266791,"journal":{"name":"Proceeding of Tenth International Symposium on Turbulence and Shear Flow Phenomena","volume":"10 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":"115180279","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":"EVALUATION OF OLFACTORY SEARCH ALGORITHMS USING DIRECT NUMERICAL SIMULATION OF TURBULENT SCALAR TRANSPORT","authors":"C. Panagiotou, D. Cerizza, T. Zaki, Y. Hasegawa","doi":"10.1615/tsfp10.800","DOIUrl":"https://doi.org/10.1615/tsfp10.800","url":null,"abstract":"","PeriodicalId":266791,"journal":{"name":"Proceeding of Tenth International Symposium on Turbulence and Shear Flow Phenomena","volume":"1 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":"114721687","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":"Development and Validation of an MRI-Based Method for Particle Concentration Measurement","authors":"Daniel D. Borup, C. Elkins, J. Eaton","doi":"10.1615/tsfp10.480","DOIUrl":"https://doi.org/10.1615/tsfp10.480","url":null,"abstract":"Dilute, dispersed multiphase flows are of critical importance in engineered, environmental, and biological applications. Traditional laser-based techniques are limited to data acquisition in discrete 2D planes with optical access required. Magnetic Resonance Imaging (MRI) is finding increasing use as a diagnostic for 3D measurements in complex turbulent flows where no optical access is possible. A new diagnostic called Magnetic Resonance Particles (MRP) has been developed whereby the volume fraction of dispersed microparticles in water can be measured quantitatively. Data obtained for dilute loadings of bismuth, graphite, and titanium powder suspended in agar gel showed excellent agreement with theoretical predictions from the MRI literature. The spatial extent of signal disturbance was investigated using an individual stainless steel particle suspended in gel. Finally, a full-scale experiment was performed in which a streak of titanium particles was injected into a complex, turbulent channel flow. Calibration values were obtained using an integral flux method and the resulting particle concentration distribution was analyzed. The calibration values showed some disagreement with theory; this issue will be the focus of upcoming calibration experiments in a channel flow with homogeneous particle distribution. INTRODUCTION Dilute, dispersed multiphase flows are of interest in a wide range of applications including dust ingestion in aircraft engines, medicinal inhalants in the human airways, and sedimentary transport in coastal ecosystems. In commercial aircraft, the introduction of atmospheric dust can shorten engine service life significantly (Dunn et al., 1987), while volcanic ash can cause near-instantaneous engine failure (Dunn, 2012). Improved knowledge of, and prediction capabilities for particle transport characteristics in a turbine engine’s various subsystems would lead to improved efficiency in a major global industry. When inhaled by humans, particulate matter can be either beneficial (e.g., medicines) or harmful (e.g., airborne pollutants), but in either case it is useful to know where the particles are likely to flow and accumulate. A comprehensive review of particle transport in the human airways was provided by Kleinstreuer ∗Contact Author & Zhang (2010). Despite the wealth of applications in which detailed particle flow quantification would be beneficial, there are significant limitations on the collection of particle concentration data using currently available techniques. Such techniques are almost entirely based on optical methods in which data are acquired in distinct 2D planes through the use of a laser sheet and camera. This 2D acquisition limits the rate at which data can be obtained. Moreover, allowing undistorted optical access for the laser-camera pair imposes severe restrictions on the complexity of the geometry that can be studied. While 3D data sets can be amassed as a stack of 2D planes, the time, cost, and complexity o","PeriodicalId":266791,"journal":{"name":"Proceeding of Tenth International Symposium on Turbulence and Shear Flow Phenomena","volume":"176 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":"114752897","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":"UNSTEADY SURFACE PRESSURE INDUCED BY TURBULENCE OVER ASYMMETRICALLY BEVELED TRAILING EDGE","authors":"Yaoyi Guan, Scott C. Morris","doi":"10.1615/tsfp10.1030","DOIUrl":"https://doi.org/10.1615/tsfp10.1030","url":null,"abstract":"Turbulence convecting over the trailing edge of a lifting surface results in surface pressure fluctuations, which is the dominating source for aerodynamic sound in low Mach number flow. The characteristics of the unsteady surface pressure (USP) are highly dependent on the flow patterns near the trailing edge. In present study, the characteristics of unsteady surface pressure induced by turbulent flow over a family of asymmetrically beveled trailing edges were studied experimentally. The geometries had a trailing-edge angle θ = 25∘ with a flat lower surface and a rounded upper surface with radii of curvature between 1 and 6 times the airfoil thickness. The chord-based Reynolds number was Re = 2.1×106. A detailed description of the USP and flow fields around the trailing edge section was obtained by remote microphone probes (RMP) and particle image velocimetry (PIV), respectively. The beveled upper surface was characterized by a region of favorable pressure gradient, followed by a strong adverse pressure gradient. The cases with smaller radius of curvature were founded to exhibit larger separated region over the trailing edge. The spectral magnitudes of USP were largest in separation region. This paper is focused on scaling and understanding the USP spectra in regions of separated flow. The PIV measurements were utilized to provide the corresponding length and velocity scales. The characteristics of the upper-surface unsteady pressure field were complex because of the strong non-equilibrium flow conditions. The characteristics of the pressure fluctuations under separated flow showed great variety and were dominated by various flow regimes in different frequency ranges. The spectral magnitude of the low-frequency USP under separated shear layer were dominated by the turbulence intensity in the local shear layer, but the frequency of the large-scale oscillations was governed by the turbulent wake. The mid-frequency range of the pressure fluctuations were dominated by the characteristics of local shear layer. The high-frequency content of the pressure fluctuations under separated shear layer with reverse flow was dominated by upstream-convecting turbulence created by reverse flow. The magnitude of the reverse flow-induced pressure fluctuations increased with faster negative phase speed.","PeriodicalId":266791,"journal":{"name":"Proceeding of Tenth International Symposium on Turbulence and Shear Flow Phenomena","volume":"44 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":"123417362","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":"Mixing and phase separation at supercritical and transcritical pressures","authors":"S. Hickel, J. Matheis","doi":"10.1615/tsfp10.1000","DOIUrl":"https://doi.org/10.1615/tsfp10.1000","url":null,"abstract":"We have developed a thermodynamically consistent and tuning-parameter-free two-phase model for Eulerian large-eddy simulations (LES) of liquid-fuel injection and mixing at high pressure. The model is based on cubic equations of state and vaporliquid equilibrium calculations. It can represent the coexistence of supercritical states and multi-component subcritical two-phase states via a homogeneous mixture approach without any semiempirical break-up and evaporation models. Computational results for liquid-fuel injection at transcritical operating conditions are found to agree very well with available experimental data for the ECN Spray A.","PeriodicalId":266791,"journal":{"name":"Proceeding of Tenth International Symposium on Turbulence and Shear Flow Phenomena","volume":"17 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":"129676766","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":"STATISTICS OF TURBULENT AND LAMINARIZING FLOW IN A CIRCULAR PIPE WITH A GRADUAL EXPANSION","authors":"N. Moallemi, J. Brinkerhoff","doi":"10.1615/tsfp10.530","DOIUrl":"https://doi.org/10.1615/tsfp10.530","url":null,"abstract":"","PeriodicalId":266791,"journal":{"name":"Proceeding of Tenth International Symposium on Turbulence and Shear Flow Phenomena","volume":"16 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":"122492535","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}