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 14 of 14 for “"Mistuning"”.
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Radial-turbine mistuning
… high-cycle fatigue of the turbine-wheel blades. Mistuning of the blades due to the casting process is believed to contribute to this failure mode. A laser vibrometer is used to characterize mistuning for a population of turbine wheels through the analysis of the blade-response to piezo-speaker …
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Flutter and Forced Response of Turbomachinery with Frequency Mistuning and Aerodynamic Asymmetry
… on flutter and forced response due to frequency mistuning and aerodynamic asymmetry using the single family of modes approach by assuming manufacturing tolerance. The unsteady aerodynamic forces are computed using CFD methods assuming aerodynamic symmetry. The aerodynamic asymmetry is applied by …
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Friction effects on collective mechanisms of short term memory
… can enhance the robustness of eye fixations to mistuning while reproducing the observed linear relationship between neuronal firing rates and eye position. We calculate the network dynamics and tolerance to mistuning. Finally, we demonstrate that dendritic bistability can improve robustness in a …
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Seismic isolation of buildings for vertical earthquake excitations
… of uncertainties in the payload as well as mistuning in the system are addressed. It is seen that the QZSS is very sensitive to any changes in payload or mistuning, while HSLDSS is unaffected by slight changes to load or initial geometry. In addition, the effects of linear and nonlinear …
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Reduced-order aerodynamic models for aeroelastic control of turbomachines
… wear. These blade to blade variations, known as mistuning, have been shown to have a significant effect on compressor aeroelastic properties. A reduced-order aerodynamic model is developed for a twenty-blade transonic rotor operating in unsteady plunging motion, and coupled to a simple typical …
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Applications of Béla Bartók's techniques of pitch organisation to jazz improvisation
… research identifies four melodic techniques: ‘mistuning’, ‘chromatic compression and diatonic extension’, ‘polymodal chromaticism’, and ‘inversional symmetry’. These four techniques inform a reflexive practice-led research project developing a collection of practice methods aimed at …
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Design and analysis of ground stations for Pacsat applications
… An analysis approach that addresses the mistuning problem is presented. Results of this analysis identify changes that would better suit the needs of PACSAT terminals.
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An investigation of concurrent segregation abilities in autistic spectrum disorder utilizing the dichotic pitch and mistuned harmonic paradigms
… of the interaural time difference (ITD) cue to mistuning increased the ORN amplitude in both groups. An ORN was elicited by ITD alone for Experiment 2. Experiment 3 revisited the dichotic pitch stimulus and utilized ITD and interaural amplitude difference (IAD) cues separately. Both groups …
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Multi-resonant Electromagnetic Shunt in Base Isolation for Vibration Damping and Energy Harvesting
… harvesting, and is also more robust in parameter mistuning than the series shunt circuit. The time history response analysis shows that, under the recorded Northridge earthquake, the instant peak power and total average power capable to be harvested by the multi-resonant shunt can reach up to 1.18 …
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Advanced optical calibration of the Herschel HIFI heterodyne spectrometer
… significant IF gain effects due to a diplexer mistuning problems. Band 5 had spurious LO signals at certain frequencies making the data observed unusable. Bands 6 & 7 had significant standing wave issues due to a non-optimal IF chain design. These instrument effects are discussed in detail in …
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Effects of non-linear stiffness on performance of an energy harvesting device
… off rapidly if mistuned. To accommodate the mistuning limitations, new types of generators are proposed mainly by using a non-linear mechanism.These mechanisms are made up of a non-linear spring connected together with a mass and a linear viscous damper i.e. the energy harvesting component. …
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Using Magneto-Rheological Dampers in Semiactive Tuned Vibration Absorbers to Control Structural Vibrations
… applications, inevitable off-tuning (or mistuning) of a TVA occurs because of the system's operating conditions or parameter changes over time. For example, the mass in a building floor could change by moving furnishings, people gathering, etc., which can "off-tune" TVAs. When TVAs are …
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Prediction of natural frequencies of turbine blades for turbocharger application. An investigation of the finite element method, mathematical modelling and frequency survey methods applied to turbocharger blade vibration in order to predict natural frequencies of turbocharger blades.
Methods of determining natural frequencies of the D76D88, B76D88, A86E93, C86G90, C86L90 and C125L89 turbine wheel designs for various environmental conditions were investigated by application of Finite Element Analysis and beam theory. Modelling and simulation methods were developed ; the first …
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Preliminary design tools in turbomachinery: Non-uniformly spaced blade rows, multistage interaction, unsteady radial waves, and propeller horizontal-axis turbine optimization
<p>Turbomachinery flow fields are inherently unsteady and complex which makes the related CFD analyses computationally intensive. Physically based preliminary design tools are desirable for parametric studies early in the design stage, and to provide deep physical insight and a good starting point …