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 16 of 16 for “"Rotor-stator interaction"”.
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Wake Filling Techniques for Reducing Rotor-Stator Interaction Noise
… method for reducing the momentum deficit in a rotor wake and thus attenuate rotor-stator interaction noise. A secondary concern of the project was to reduce the amount of blowing required air for wake filling and thus limit the efficiency penalty in an aircraft engine environment. Testing was …
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Turbofan rotor/stator interaction noise reduction through trailing edge blowing
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1998.
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Reduction of Unsteady Rotor-Stator Interaction Using Trailing Edge Blowing
… adding mass flow at the trailing edges of four stators upstream of an aircraft engine simulator. By using trailing edge blowing to minimize the shed wakes of the stators, the flow into the rotor was made more uniform. In these experiments a reduced number of stators (four) was used in a 1/14 …
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Experimental Investigation of Flow Control Techniques To Reduce Hydroacoustic Rotor-Stator Interaction Noise
… along the forebody and propulsor fluid-structure interaction. The propulsor contains several locations of such interaction, one of which was investigated in this research. Specifically, this research focused on experimentally investigating active flow control techniques to reduce rotor-stator …
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Numerical simulation of unsteady rotor/stator interaction and application to propeller/rudder combination
… has been developed in order to simulate unsteady rotor/stator interaction, and to predict the unsteady performance of a propeller and its rudder. The method is first developed and tested in two-dimensions by using a boundary element method in which a front hydrofoil is moving downward, while a …
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Two-dimensional analysis of rotor suction and the impact on rotor-stator interaction noise
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1994.
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Towards a silent fan: an investigation of low-speed fan aeroacoustics
… Periodicity in the impeller outlet flow produces rotor-stator interaction tones even with a number of guide vanes chosen to satisfy the Tyler-Sofrin theory cut-off criteria. This is thought to be due to abrupt radius change after the guide vanes in the rig (while the theory assumes constant …
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Mathematical modelling of noise generation in turbofan aeroengines using Green’s functions
… The main topic of this thesis is investigating rotor-stator interaction which occurs when the turbulent, swirling air produced by the rotor hits the stator and generates noise. We do this in two distinct ways, firstly we calculate the Green’s function for pressure in a turbofan duct with …
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Advanced Trailing Edge Blowing Concepts for Fan Noise Control: Experimental Validation
… edge blowing research performed to reduce rotor / stator interaction noise in turbofan engines. The existing technique of filling every velocity deficit requires a large amount of air and is therefore impractical. The purpose of this research is to investigate new blowing configurations in …
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Generation of Downstream Vorticity Through the Use of Modified Trailing Edge Configurations
… velocity into the flow behind a cascade of GE Rotor B fan blades. These measurements were conducted in the Virginia Tech Low Speed Linear Cascade wind tunnel. The trailing edge configurations tested utilized passive techniques for producing streamwise vorticity, which in turn causes downstream …
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Theoretical prediction of counter-rotating propeller noise
… radiated sound field generated by aerodynamic interactions between the blade rows. Here, however, the inputs to the formulae include a knowledge of the fluctuating blade pressure fields which cannot generally be assumed given and must therefore be calculated within the prediction scheme. In the …
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Structural Characterization of F-type and V-type Rotary ATPases by Single Particle Electron Cryomicroscpy
… or hydrolysis. The rotation of the central rotor, which is powered by the flow of proton (or sometimes sodium ion) down the electrochemical gradient through the membrane-bound Fo/Vo region, leads to the chemical synthesis of ATP in F1/V1 region. The F1/V1 region, on the other hand, can …
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Broadband Noise Prediction of an Axial Compressor Operating at Low Reynolds Number
… by designing and constructing a new single stage rotor-stator compressor on which the subsequent research was based. The work utilized a combination of experimental, computational and analytical methods. Aerodynamic and acoustic properties were measured on the compressor installed in a duct with …
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On the Use of Surface Porosity to Reduce Wake-Stator Interaction Noise
… the effects of transient phenomena, such as rotor-stator and rotor-strut interactions, linked to noise and fatigue failure in turbomachinery environments. A computational study was designed to assess the potential of Passive Porosity Technology as a mechanism for alleviating interaction …
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Modifications of Coherent Structures in Fan Blade Wakes for Broadband Noise Reduction
… the likely effects on broadband aircraft engine interaction noise. Single and three-component hotwire velocity measurements were made downstream of the cascade for a chord Reynolds number of 390,000 and a Mach number of 0.07. Measurements of the two-point velocity correlation were used …
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Bio-Inspired Axial Fan Design, 3D Printing Fabrication and Characterization for Noise and Flow Performance Optimization
… constitute the building blocks of fan blades and rotor–stator interactions. The overall objective is to develop predictive tools and passive noise-control strategies for next-generation low-noise axial fan systems. The analysis begins with the investigation of airfoil self-noise mechanisms, which …