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 21 for “"rotordynamic"”.
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Aerodynamic-rotordynamic interaction in axial compression systems
Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2000.
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Modelling of Passive Magnetic Bearings for Rotordynamic Analysis
L'abstract è presente nell'allegato / the abstract is in the attachment
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Rotordynamic Analysis of Theoretical Models and Experimental Systems
… for the construction and</p> <p>analysis of rotordynamic theoretical models, and their comparison the experimental</p> <p>systems. Finite Element Method (FEM) is used to construct models using Timoshenko</p> <p>beam elements with viscous and hysteretic internal damping. Eigenvalues</p> <p>and …
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Rotordynamic assessment for a permanent magnet synchronous motor
… stator. This architecture introduces significant rotordynamic challenges, one of which is the “trunnion effect,” a rotordynamic effect uncommon in traditional electric machines. This effect was identified when a discrepancy was observed during a rotor test and a root-cause analysis was performed …
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Forced Response System Identification of Full Aero-Engine Rotordynamic Systems
A new class of rotordynamic challenges have surfaced in advanced turbofan engine designs where there are opportunities for dynamical coupling between rotor shafts and support structures, requiring entire system-level assessment. Addressing such vibration challenges relies on knowledge of damping …
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Computational Fluid Dynamic and Rotordynamic Study on the Labyrinth Seal
… of tooth locations are all factors affecting the rotordynamic properties of the labyrinth seal. So it is of interest to investigate the exact relationships between those factors and the seal's rotordynamic properties. In this research, three types of labyrinth seals have been modeled: the straight …
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Experimental and theoretical investigation of rotordynamic instability in a shrouded turbine
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1992.
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Design of a Low-Cost Data Acquisition System for Rotordynamic Data Collection
<p>A data acquisition system (DAQ) was designed based on the use of a STM32 microcontroller. Its purpose is to provide a transparent and low-cost alternative to commercially available DAQs, providing educators a means to teach students about the process through which data are collected as well as …
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Experimental investigation of rotordynamic instabilities caused by rotor blade-tip excitation forces
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1989.
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Surface Patterning and Rotordynamic Response of Annular Pressure Seals Used in Turbomachinery
Rotordynamic instability problems in turbomachinery have become more important in recent years due to rotordynamic components with higher speeds and higher power densities. These features typically lead to increased instability risk in rotor dynamic components as fluids-structure interactions take …
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Rotordynamic performance of a rotor supported on bump-type foil bearings: experiments and predictions
… minimal amounts of damping. A test rig for the rotordynamic evaluation of gas foil bearings was constructed. A DC router motor, 25 krpm max speed, drives a 1.02 kg hollow rotor supported on two bump-type foil gas bearings (L = D = 38.10 mm). Measurements of the test rotor dynamic response were …
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Development of a Rotordynamic Signal Processing MATLAB Interface and a Two-Disk Rotor Model
… program meant to monitor the behavior of rotordynamic systems in real-time was developed and tested. By using traditional analysis methods in this field of engineering, commonly desired data representations such as bode, polar, orbit, full spectrum plots were able to be produced to a very …
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Rotordynamic analysis of circumferentially grooved annular pump seals with turbulent flow and inlet swirl
… experimental test results for seal leakage and rotordynamic coefficients. Actual quantitative agreement is unresolved given the high level of experimental uncertainty in the test results.
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The impact of unsteady swirling flow in a single gland labyrinth seal on rotordynamic stability : theory and experiment
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1992.
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Measured and predicted rotordynamic coefficients and static performance of a rocker-pivot, tilt pad bearing in load-on-pad and load-between-pad configurations
This thesis presents the static and dynamic performance data for a 5 pad tilting pad bearing in both the load-on-pad (LOP) and the load-between-pad (LBP) configurations over a variety of different loads and speeds. The bearing tested was an Orion Advantage with direct lubrication exhibiting these …
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Development of a MEMS turbocharger and gas turbine engine
… purposes, intended for turbomachinery and rotordynamic development. The turbocharger design described herein was evolved from an earlier, unsuccessful design (Protz 2000) to satisfy rotordynamic and fabrication constraints. The turbochargers consist of a back-to-back centrifugal compressor …
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Influence of Induced Unbalance on Subsynchronous Vibrations of an Automotive Turbocharger
Rotordynamic instability is present in most or all automotive turbochargers. High subsynchronous amplitudes can cause a variety of problems in areas such as mechanical failures, emissions regulations and rotor design. Self-excited vibrations from sources of damping can lock in at lateral natural …
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MEMS turbomachinery rotordynamics : modeling, design and testing
… bearing operation, labyrinth seals for reducing rotordynamic coupling, a redesigned turbine for satisfying power requirements, reinforced thrust bearing structural design, a novel rotor fabrication technology for achieving low radial imbalance and a symmetric feed system to avoid rotor …
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Developments on Electrodynamic Levitation of Rotors
… complex coordinate representation, typical in rotordynamics, in order to enable easy integration of the bearing's model with different rotordynamic models. An experimental validation of the model is carried out for homopolar configurations. The study of the dynamics of rotors on electrodynamic …
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Development of a high-speed rotating bar mechanism
… to 1.7. In addition to the stress analysis, a rotordynamic study was also performed. The study revealed that the RBM could not be designed to operate below the first natural frequency. A critical speed of 14,000 RPM was predicted for the rotary device. This prediction was later verified by …
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