Global ETD Search
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Showing 1 to 16 of 16 for “"Flow-Control Devices"”.
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Covert-inspired flow control devices for lift enhancement and stall mitigation
… Reynolds numbers. A system of aeroelastic devices used by birds, known as the covert feathers, has been considered as a natural flow-control device for mitigating flow separation, enhancing lift, and delaying stall. In order to improve the mission adaptability of small-scale UAVs, this …
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The use of flow control devices to improve the flow pattern and throughput of sieve trays
… most widely used sieve trays) is not in any way controlled. The two important results of the gas/liquid interaction are the tray efficiency and the tray throughput or capacity. After many years of practical experience, both may be predicted by empirical correlations, despite the lack of …
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Active Flow Control of Subsonic Flow in an Adverse Pressure Gradient Using Synthetic Jets and Passive Micro Flow Control Devices
… shown the advantages of active and/or passive flow control devices for boundary layer flow modification. Many current and future proposed air vehicles have very short or offset diffusers in order to save vehicle weight and create more optimal vehicle/engine integration. Such short coupled …
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A numerical investigation of s-duct flows with boundary-layer ingestion
… conducted to further NASA's study of active flow control systems for a flush-mounted inlet with significant boundary-layer ingestion (BLI). In conjunction with a NASA-sponsored research grant, the aim is to further accumulate knowledge and insight on the effectiveness of flow control …
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Boundary Layer Separation Control on a Salient Back-facing Ramp
… feasibility and the performance of the serration flow control devices on a salient edge where the laminar boundary layer separation is two-dimensional. Three geometries of serrations: a sharp delta, a double delta and a divergent delta are examined on 15° and 30° deflected, backward-facing ramps. …
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Improvement In Acoustic Liner Attenuation In Turbofan Engines By Means Of Plasma Synthetic Jet Actuator
Despite many advances in aviation noise control over the past 50 years, the industry is continually striving to reduce noise emissions. Turbofan engine acoustic liners are efficient attenuators of engine noise. Plasma actuators have been used as flow control devices in other settings and will now …
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Multiphysics modelling of geometrically-complex flow metering devices
The simulation of complex multiphase flows has been the subject of extensive research for decades, owing to the wide range of industrial and natural processes involving the interaction of two or more fluids, particularly in the presence of variable geometries. This is essential for multiphase flow …
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Synthesis and Characterization of Functional Mesostructures Using Colloidal Crystal Templating
… as electrochemical elements, sensors, flow control devices, and novel photonic band gap materials. Inverse opal conducting polymer films were fabricated by electropolymerization. The templated films exhibited a compact morphology and larger electrochemical response from cyclic …
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Flow patterns and performance of distillation trays
… tray efficiency depends on the liquid flow pattern, particularly for large diameter trays. Scale·up failures due to liquid channelling have occurred, and it is known that fitting flow control devices to trays sometirr.es improves tray efficiency. Several theoretical models which explain …
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Design and development of a rectangular supersonic wind tunnel facility for the study of shock/boundary layer interactions
… inlet shock wave/boundary layer interaction control options, called micro-vortex generators. A new supersonic wind tunnel was designed and built on the University of Illinois campus to enhance high-speed flow testing capabilities used for studying these flow-control devices. A newer and …
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Designing Shock Control Bumps for Transonic Commercial Aircraft
Shock control bumps (SCBs) are considered promising flow control devices for transonic commercial aircraft. By generating a λ-shock structure, 2D SCBs offer large drag savings, but perform poorly when that structure breaks down off-design. Milder-performing 3D devices produce weak vortices, that …
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Model-Based Control Development for an Advanced Thermal Management System for Automotive Powertrains
… speed pumps and fans, as well as active fluid flow control devices that allows for a greatly improved freedom to manage the heat rejection and thermal management of the engine and transmission components. This control authority can be exploited, for instance, to rapidly warm the powertrain …
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Hydraulic Effects of Perpendicular Water Approach Velocity on Meter Gate Flow Measurement
<p>Accurate flow measurement is required to effectively manage water resources. California Senate Bill X7-7 (SB X7-7), legislates this need by requiring agricultural water providers serving areas greater than 25,000 acres to develop an Agricultural Water Management Plan (AWMP) and adopt pricing …
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The effects of micro-vortex generators on normal shock wave/boundary layer interactions
… interactions (SWBLIs) are complex flow phenomena that are important in the design and performance of internal supersonic and transonic flow fields such as engine inlets. This investigation was undertaken to study the effects of passive flow control devices on normal shock …
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Control of supersonic axisymmetric base flows using passive splitter plates and pulsed plasma actuators
… investigation evaluating the effects of flow control on the near-wake downstream of a blunt-based axisymmetric body in supersonic flow has been conducted. To better understand and control the physical phenomena that govern these massively separated high-speed flows, this research examined …