Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 63 for “"tip leakage"”.
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Control of tip-leakage flows using periodic excitation
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2000.
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Tip leakage flow in a linear turbine cascade
… performed to study the details of flow in the tip clearance gap of a linear turbine blade cascade. The cascade was designed and built to be geometrically similar to the earlier VPI&SU cascade; however, the new cascade also had a tip gap (2.1 percent of blade height) and two endwall boundary …
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Tip leakage losses in a linear turbine cascade
An investigation of tip leakage flow and its effects on loss production was performed on a large-scale linear turbine cascade having a tip gap measuring 2.1% of the blade height. The Reynolds number based on axial chord and cascade exit velocity was 4.5x10⁵. The experimental work began with a …
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Reynolds stress measurements in a turbine tip leakage vortex
… study of the structure of turbulence in a tip leakage vortex was conducted in a large scale, linear turbine cascade. The study was performed in a cross sectional plane 0.96 of the axial chord length downstream of the blade leading edge. The cascade consisted of five blades with an aspect …
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Flowfield Downstream of a Compressor Cascade with Tip Leakage
… blade, 7 passage linear compressor cascade with tip leakage was built. The flowfield downstream of the cascade was measured using four sensor hot-wire anemometers, from which the mean velocity field , the turbulence stress field and velocity spectra were obtained. Oil flow visualizations were …
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Tip leakage loss development in a linear turbine cascade
Tip leakage losses were studied in a linear turbine cascade with a tip clearance gap equal to 2.1 percent of blade height. The blades of the cascade have a turning angle of 109.4 degrees, an aspect ratio of 1.0, and an axial chord length of 235.2 mm. The cascade was located at the exit of a low …
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A study of tip-leakage flow through orifice investigations
… of gaining insight into the fluid dynamics of tip leakage flow. The Reynolds number range investigated was greater than 10*. Measurements were made of the discharge coefficient as a function of back pressure ratio for a sharp-edged orifice and long orifices with an l/d from 1/2 to 8. The …
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Effects of upstream unsteady flow conditions on rotor tip leakage flow
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 2001.
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Tip Leakage Flow Downstream a Compressor Cascade with Moving End Wall
… effects of the relative motion between the blade tips and casing upon the flow. Detailed 4-sensor hot wire measurements were made at various locations downstream the cascade. The results are presented in term of mean flow field and turbulence flow field. In order to reveal the effects of moving …
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Tip leakage flow, heat transfer and blade lifing in a jet engine turbine
… developing flow and heat transfer in turbine tip gaps. Successful calculations of the heat transfer to a model turbine blade tip were obtained with a Prandtl mixing length turbulence model. The calculations revealed details of the flow development including recirculation and reattachment on …
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An Experimental Characterization of Tip Leakage Flows and Corresponding Effects on Multistage Compressor Performance
The effect of rotor tip clearances in turbomachinery applications has been a primary research interest for nearly 80 years. Over that time, studies have shown increased tip clearance in axial flow compressors typically has a detrimental effect on overall pressure rise capability, isentropic …
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The Effects of Shrouded Rotor Tip Leakage Flow on the Downstream Stator Aerodynamics in Turbines
… necessitates radial clearance gaps above the tips of the rotor blades and below the hub end of the stator blades. Therefore, a fraction of the gas does not pass through the blade rows, but instead leaks through the tip and hub cavities into the downstream blade row. The leakage flow over …
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Unsteady Turbulence Interaction in a Tip Leakage Flow Downstream of a Simulated Axial Compressor Rotor
The unsteady behavior of a tip leakage flow downstream of a simulated axial compressor rotor has been studied. The Virginia Tech low speed linear cascade wind tunnel was adapted to model the unsteady tip leakage flow produced by a rotor operating in the vortical wakes of a set of stator vanes. The …
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Formation and Development of the Tip Leakage Vortex in a Simulated Axial Compressor with Unsteady Inflow
The interaction between rotor blade tip leakage vortex and inflow disturbances, such as encountered in shrouded marine propulsors, was simulated in the Virginia Tech Linear Cascade Wind Tunnel equipped with a moving endwall system. Upstream of the blade row, idealized periodic inflow unsteadiness …
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Near Wall Behavior of Vortical Flow around the Tip of an Axial Pump Rotor Blade
… study of three-dimensional turbulent tip gap flow in a linear cascade wind tunnel with 3.3% chord tip clearance with and without moving endwall simulation. Experimental measurements have been completed in Virginia Tech low speed linear cascade wind tunnel. A 24" access laser-Doppler …
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Turbine tip clearance loss mechanisms
… the actual turbine environment, on turbine blade tip loss. The calculations were carried out for a subsonic high pressure turbine stage. The loss mechanism examined is that due to tip clearance vortex mixing. The effects examined were three-dimensional blade stacking, downstream transition duct …
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The Effects of Free Stream Turbulence on the Flow Field through a Compressor Cascade
The flow through a compressor cascade with tip leakage has been studied experimentally. The cascade of GE rotor B section blades had an inlet angle of 65.1º, a stagger angle of 56.9º, and a solidity of 1.08. The final turning angle of the cascade was 11.8º. This compressor configuration was …
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Effects of Tip Clearance and Surface Roughness on Small-Scale Turbopump Impeller Performance
… to characterize the impact of impeller blade tip clearance and surface roughness on the performance of small-scale turbopump impellers by assessing the dominant flow features, quantifying the underlying loss mechanisms, and determining the sensitivity of performance losses to changes in tip …
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