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Showing 1 to 20 of 32 for “"DPIV"”.
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Time-Resolved Analysis of Circulation Control over Supercritical Airfoil using Digital Particle Image Velocimetry (DPIV)
… time accurate flow visualization technique (DPIV). Vorticity behavior was investigated using Tecplot® and a MATLAB® program was developed to quantify the Strouhal Number of time-averaged velocity fluctuations moving aft of the Coanda surface for each case.
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Development of Robust Correlation Algorithms for Image Velocimetry using Advanced Filtering
Digital Particle Image Velocimetry (DPIV) is a planar measurement technique to measure the velocity within a fluid by correlating the motion of flow tracers over a sequence of images recorded with a camera-laser system. Sophisticated digital processing algorithms are required to provide a high …
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Integration and Validation of Flow Image Quantification (Flow-IQ) System
… aim of this work was to test the performance of DPIV algorithms in wall shear flows, and to test the performance of several particle sizing algorithms for use in spray sizing and average diameter calculation. Several particle sizing algorithms which assume a circular particle profile were tested …
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A Hybrid Dynamically Adaptive, Super-Spatio Temporal Resolution Digital Particle Image Velocimetry for Multi-Phase Flows
… resolution Digital Particle Image Velocimetry (DPIV) system with capability of resolving velocities in a multi-phase flow field, using a very sophisticated novel Dynamically Adaptive Hybrid velocity evaluation algorithm has been developed The unique methodology of this powerful system is …
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Geometry induced flow disturbances
… Digital Particle Image Velocimetry (DPIV) to compare the hemodynamic performance of two stents in a compliant vessel. The first stent was a rigid insert, representing an extreme compliance mismatch. The second stent was a commercially available nitinol stent with some flexural …
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Experimental Investigation of the Effects of a Passing Shock on Compressor Stator Flow
… and Digital Particle Image Velocimetry (DPIV). Measurements were taken for three different shock strengths. In every case studied, a vortex formed near the stator trailing edge as the shock impacted the blade. The size of this vortex was shown to be directly related to the shock strength, …
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An Investigation of Dolphin-Groove Inspired Surface Patterning on Flow Control
… digital particle image velocimetry (TR-DPIV) was used to track the development of the flow separation within the boundary layer and compared to the smooth plate (non-grooved) wall cases. The grooved surfaces form embedded vortices within the sinusoidal cavities which can lead to a …
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Mixing at Low Reynolds Numbers by Vibrating Cantilevered Ionic Polymers
… tested and Digital Particle Image Velocimetry (DPIV) measurements were obtained. Resulting analysis using a quantitative mixing metric shows that using cantilevered polymers create increases mixing potential in the flow for some actuation cases. Although these differences are present, they do …
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Subpixel Resolution Schemes for Multiphase Flows
… for Digital Particle Tracking Velocimetry (DPIV). The errors of these new methods were classified through Monte-Carlo simulations. These schemes provide direct measurements of the apparent particle image diameter and the subpixel position. The new methods significantly reduce the bias error …
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Flapping motion of a three-dimensional foil for propulsion and maneuvering of underwater vehicles
… (LDV) and Digital Particle Imaging Velocimetry (DPIV) in three ancillary experiments. First, mean velocities across the wake at five spanwise locations were recorded using LDV. The wake width was found to be the excursion of the foil at the 70% span, validating our previous assumption. In the …
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Multiphase Hydrodynamics in Flotation Systems
… using Digital Particle Image Velocimetry (DPIV). The experimental results were compared with the predictions from empirical and theoretical collision models. Time-resolved DPIV was used to measure the turbulent velocity field in a Rushton turbine around the impeller region. The turbulence …
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Modification of Blade-Vortex Interactions Using Leading Edge Blowing
… using Digital Particle Image Velocimetry (DPIV) and accelerometer measurements in a time-resolved sense. The results indicate that LEB can significantly reduce the degree of unsteady loading due to the blade vortex interaction (BVI). In some cases, the LEB jet appears to break the coherency …
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Laminar and Transitional Flow disturbances in Diseased and Stented Arteries
… using Digital Particle Image Velocimetry (DPIV), (b) Complex geometric effects of stented arteries with emphasis on its design parameters is investigated using CFD, Also (c) a novel method to improve the accuracy of velocity gradient estimation in the presence of noisy flow fields such as …
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Shear flow visualization at high Reynolds Numbers
… and Digital Particle Image Velocimetry (DPIV). In addition, the experimental apparatus was modified for similar flow visualization near live fish, and a description of this endeavor and its progress are included.
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The contribution of the pectoral fins, body, and the ribbon fin to turning maneuvers of a gymnotiform swimmer
… large turns. Digital particle image velocimetry (DPIV) showed that the ribbon fin generates larger counter rotating vortices during turning than is produced during steady swimming. All three control surfaces contributed to steady swimming and large turns while small turns relied mostly on …
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Vorticity control for efficient propulsion
… this thesis, digital particle image velocimetry (DPIV) is used to make quantitative multipoint measurements of the unsteady flow fields. Fish are the prime example of vorticity control: they propel and maneuver by manipulating vorticity formed along their body which interacts with the tail. …
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Experimental Investigations into Shark Skin Inspired Active Flow Control Mechanisms
… using digital particle image velocimetry (DPIV).The flaps in this study had a rectangular shape and were designed with a protrusion heightin the bottom 10% of the boundary layer height, which is similar to that of the flexiblescales found on the mako shark. The flaps were embedded into a …
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Hemodynamic Flow Characterization of St. Jude Medical Bileaflet Mechanical and Bioprosthetic Heart Valve Prostheses in a Left Ventricular Model via Digital Particle Image Velocimetry
… the aorta. Digital Particle Image Velocimetry (DPIV) has also been utilized to reveal intricate patterns of interacting shed vortices downstream of the aortic valve. The orientation of the valves may considerably affect the flow development and slight difference may produce significant …
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Hydrodynamics of jumping in archer fish, Toxotes microlepis
… high speed digital particle image velocimetry (DPIV). The kinematic study is able to successfully break the jumping behavior into three parts: (1) hovering, (2) thrust production and (3) gliding. Hovering is when the fish is beneath the surface of the water and is trying to maintain position. …
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Wall shear measurements in arterial flows
… Digital Particle Image Velocimetry (DPIV) velocity measurements. A new velocity derivative method, the fourth-order noise-optimized compact-Richardson implicit scheme, has been developed, overcoming the obstacle of minimizing both the bias and random error in temporal/spatial …
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