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.
Results
Showing 1 to 11 of 11 for “"blade vibration"”.
-
Evaluation of optical techniques applied to online turbomachinery blade vibration measurements
Understanding the dynamic characteristics of blades is important in the online condition monitoring of turbomachinery. Conventionally contact methods are used for this purpose. However improvements in technology now allow for the use of non-contact methods. Contact measurement techniques for …
-
Aeroelastic Modeling of Blade Vibration and its Effect on the Trim and Optimal Performance of Helicopter Rotors using a Harmonic Balance Approach
… to model the structural</p><p>eects of the blade, and a coupled induced velocity/projected force model is used</p><p>to couple this structural model to the aerodynamic model constructed in previous</p><p>works. The system is then optimized using two separate objective functions: …
-
Vibration and crack detection in gas turbine engine compressor blades using Eddy current sensors
… the ECS signal, no definitive method for sensing blade vibration using an ECS has yet been developed.
-
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.
… improvement in accuracy of prediction of modal vibration. A new nomenclature for the mode shapes of a turbocharger’s blade was proposed, designed and demonstrated to allow direct identification of associated mode shape. It is concluded that Finite Element Analysis combined with the frequency …
-
Vibration detection in turbomachinery using non-contacting sensors
… employ an active magnetic field to monitor each blade as it passes the sensor. They generate an electrical signal proportional to the distance of a blade from the sensor. Existing algorithms extract two pieces of information from the ECS signature, signal magnitude and signal zero crossing time. …
-
Simulation of 3-D viscous compressible flow in multistage turbomachinery by finite element methods
The flow in a multistage turbomachinery blade row is compressible, viscous, and unsteady. Complex flow features such as boundary layers, wake migration from upstream blade rows, shocks, tip leakage jets, and vortices interact together as the flow convects through the stages. These interactions …
-
Methods for Validation of a Turbomachinery Rotor Blade Tip Timing System
… evaluate the performance of a novel blade tip timing (BTT) system from Prime Photonics, LC. The research focused on creating known blade tip offsets and tip vibrations so that the results from a BTT system can be validated. The topic of validation is important to the BTT field as the …
-
A Computational Study of Compressor Inlet Boundary Conditions with Total Temperature Distortions
… at the compressor face that may affect rotor blade vibration. Both analyses show that holding static pressure constant is an appropriate boundary condition for flow modeling at the compressor inlet. The analyses indicate that in addition to the introduction of a thermal distortion, there is a …
-
Dynamic Response and Containment of Blade Shedding in Gas Turbine Engines
In this thesis, the problem of blade shedding in aviation gas turbine engines (GTE) is investigated analytically, numerically and experimentally. The work is divided into three integrated sections. The first is concerned with the dynamic response of traditional metallic blades and advanced metal …
-
Effects of Inlet Guide Vane Flow Control on Forced Response of a Transonic Fan
… to the high-cycle fatigue of compressor blades is the response to aerodynamic forcing functions generated by an upstream row of stators or inlet guide vanes. Resonant response to engine order excitation at certain rotor speeds is especially damaging. Studies have shown that flow control …
-
Numerical lnvestigation of Disturbance Environments in Low Pressure Turbines
… turbulence (FST), unsteady wakes, roughness and blade oscillations on the separation-induced transition on the suction surface of a low pressure turbine blade are analyzed. Two configurations are considered: (i) a flat plate subjected to streamwise pressure gradient representative of the suction …