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 34 for “"Tip leakage Flow"”.
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Tip leakage flow in a linear turbine cascade
… was 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 …
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A study of tip-leakage flow through orifice investigations
"Compressible fluid dynamics of flow through plain-faced long orifices was investigated with the hope 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 …
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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
… code (MEFP) was used to calculate 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 …
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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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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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Impeller-diffuser interaction in centrifugal compressors
… unsteady interaction was the effect on impeller tip leakage flow . In particular, the unsteadiness due to the upstream potential effect of the diffuser vanes led to larger viscous losses associated with the impeller tip leakage flow. The consequent changes at the impeller exit with increasing …
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Effects of rotor tip blade loading variation on compressor stage performance
… generation associated with altering the rotor tip loading of an embedded compressor stage is assessed. Steady and unsteady three-dimensional computations, complemented by control volume analyses, for varying rotor tip loading distributions provided results for determining if aft-loading rotor …
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An experimental study on the effects of blade row interactions on aerodynamic loss mechanisms in a multistage compressor
… is still not well understood. The unsteady flow field consists of periodic blade row interactions from the wakes and potential fields of each blade and vane. Vane clocking is the relative circumferential indexing of adjacent vane rows with the same vane count, and it is one method to change …
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Unsteady flows in cantilever compressor stator tip clearances and the effect of real tip geometry
… performed to identify the unsteady and turbulent flow structure within compressor tip flows. The simulations were performed with clearances of 1.6 and 3.2 percent of chord. The results show that the flow both within the gap and at the exit on the suction side are highly unsteady phenomena …
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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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Design, Analysis, Optimization and Control of Rotor Tip Flows
… over the past decades, the turbine tip design presents numerous challenges to the engine manufacturers, and remains the primary factor defining the machine durability for the periodic removal of the turbine components during overhaul. Due to the hot gases coming from the upstream …
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Active control of tip clearance flow in axial compressors
Control of compressor tip clearance flows is explored in a linear cascade using three types of fluidic actuators; Normal Synthetic Jet (NSJ; unsteady jet normal to the mean flow with zero net mass flux), Directed Synthetic Jet (DSJ; injection roughly aligned with the mean flow), and Steady Directed …
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Fluid mechanics of ported shroud centrifugal compressor for vehicular turbocharger applications
… used to determine the impact of the PS on the flow field and hence performance. It is shown that the main flow path perceives the PS flow as a combination of flow actuations that include injection and removal of mass flow, and injection of axial momentum and tangential momentum. A computational …
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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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Computational study of 3D turbulent air flow in a helical rocket pump inducer
A computational study of the air flow in a helical rocket pump inducer has been performed using a 3-D elliptic flow procedure including viscous effects. The inlet flow is considered turbulent and fully developed. The geometric, definition of the inducer blade shape and the calculation grid are …
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