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Comparison of average-passage equation closures through simulation of single and multi-row axial compressors : the limitations of using a commercial CFD codeLockwood, C. January 1999 (has links)
No description available.
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A new advanced turbine-stage test facility : the concept, design, construction and commissioningFowler, Andrew January 1994 (has links)
No description available.
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Finite element static, dynamic, and flutter analysis of rotating composite layered plates and shellsAttia, Osama Abdel Moniem Mohamied January 1996 (has links)
This thesis introduces new conforming and non-conforming finite elements for the static and dynamic analysis of rotating composite layered plates and shells. The elements consider parabolic distributions of transverse shear stresses, and based on Lagrangian and Hermitian shape functions. They can deal with variable thickness distributions as well as uniform distributions, and they are fully capable to deal with rotating plate and shell structures, i.e. centrifugal stiffening and Coriolis force effects are considered. Natural frequency analysis, forced vibration analysis, and flutter analysis of composite layered plate and shell structures, employing those elements, have been investigated. A computer programming package based on the developed theory was designed, and it is machine independent and user friendly. A modular approach was adopted in the package structure to allow any further development to be considered. Efficient frontal solvers were adopted in the package for different types of analysis. The developed package has been successfully validated on a main frame computer (VAX), Unix workstations, and personal computers. Several case studies were investigated and the results obtained were compared with corresponding, published theoretical and/or experimental work. The package has proved to be a very useful tool for the design optimization of composite layered plates and shells by means of using different fibre angles for different layers so as to achieve the required strength and/or stiffness.
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Indirect measurement of vibration excitation forcesHillary, Brenda January 1983 (has links)
No description available.
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Three-dimensional design of turbomachineryBorges, J. E. January 1986 (has links)
No description available.
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The use of high frequency stress waves for detecting shaft seal rubbing and source locationLiu, Horng-Twu January 1996 (has links)
No description available.
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Prediction of turbomachinery aeroelasticity effects using a 3D non-linear integrated methodMarshall, John Graham January 1996 (has links)
No description available.
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Effect of Inlet Temperature Non-Uniformity on High-Pressure Turbine PerformanceSmith, Craig I. 01 November 2010 (has links)
The temperature of the flow entering a high-pressure turbine stage is inherently non-uniform, as it is produced by several discrete, azimuthally-distributed combustors. In general, however, industrial simulations assume inlet temperature uniformity to simplify the preparation process and reduce computation time. The effects of a non-uniform inlet field on the performance of a commercial, transonic, single-stage, high-pressure, axial turbine with a curved inlet duct have been investigated numerically by performing URANS (Unsteady Reynolds-Averaged Navier-Stokes equations) simulations with the SST (Shear Stress Transport) turbulence model. By adjusting the alignment of the experimentally-based inlet temperature field with respect to the stator vanes, two clocking configurations were generated: a vane-impinging (VI) case , in which each hot streak impinged on a vane; and a mid-pitch (MP) case, in which each hot streak passed between two vanes.
In the VI configuration, the hot streaks produced higher time-averaged heat load on the vanes and lower heat load on the blades. As the hot streaks in the VI case passed over the stator vanes, they also spread spanwise due to the actions of the casing passage vortices and the radial pressure gradient; this resulted in a stream entering the rotor with relatively low temperature variations. The hot streaks in the MP case were convected undisturbed past the relatively cool vane section. Relatively high time-averaged enthalpy values were found to occur on the pressure side of the blades in the MP configuration. The non-uniformity of the time-averaged enthalpy on the blade surfaces was lower in the VI configuration. The flow exiting the rotor section was much less non-uniform in the VI case, but differences in calculated efficiency were not significant. / Pratt & Whitney Canada, NSERC
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Effect of Inlet Temperature Non-Uniformity on High-Pressure Turbine PerformanceSmith, Craig I. 01 November 2010 (has links)
The temperature of the flow entering a high-pressure turbine stage is inherently non-uniform, as it is produced by several discrete, azimuthally-distributed combustors. In general, however, industrial simulations assume inlet temperature uniformity to simplify the preparation process and reduce computation time. The effects of a non-uniform inlet field on the performance of a commercial, transonic, single-stage, high-pressure, axial turbine with a curved inlet duct have been investigated numerically by performing URANS (Unsteady Reynolds-Averaged Navier-Stokes equations) simulations with the SST (Shear Stress Transport) turbulence model. By adjusting the alignment of the experimentally-based inlet temperature field with respect to the stator vanes, two clocking configurations were generated: a vane-impinging (VI) case , in which each hot streak impinged on a vane; and a mid-pitch (MP) case, in which each hot streak passed between two vanes.
In the VI configuration, the hot streaks produced higher time-averaged heat load on the vanes and lower heat load on the blades. As the hot streaks in the VI case passed over the stator vanes, they also spread spanwise due to the actions of the casing passage vortices and the radial pressure gradient; this resulted in a stream entering the rotor with relatively low temperature variations. The hot streaks in the MP case were convected undisturbed past the relatively cool vane section. Relatively high time-averaged enthalpy values were found to occur on the pressure side of the blades in the MP configuration. The non-uniformity of the time-averaged enthalpy on the blade surfaces was lower in the VI configuration. The flow exiting the rotor section was much less non-uniform in the VI case, but differences in calculated efficiency were not significant. / Pratt & Whitney Canada, NSERC
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Leakage and rotordynamic effects of pocket damper seals and see-through labyrinth sealsGamal Eldin, Ahmed Mohamed 15 May 2009 (has links)
This dissertation discusses research on the leakage and rotordynamic characteristics
of pocket damper seals (PDS) and see-through labyrinth seals, presents and evaluates
models for labyrinth seal and PDS leakage and PDS force coefficients, and compares
these seals to other annular gas seals. Low-pressure experimental results are used
alongside previously-published high-pressure labyrinth and PDS data to evaluate the
models. Effects of major seal design parameters; blade thickness, blade spacing, blade
profile, and cavity depth; on seal leakage, as well as the effect of operating a seal in an
off-center position, are examined through a series of non-rotating tests. Two
reconfigurable seal designs were used, which enabled testing labyrinth seals and PDS
with two to six blades.
Leakage and pressure measurements were made with air as the working fluid on
twenty-two seal configurations. Increasing seal blade thickness reduced leakage by the
largest amount. Blade profile results were more equivocal, indicating that both profile
and thickness affected leakage, but that the influence of one factor partially negated the
influence of the other. Seal leakage increased with increased eccentricity at lower
supply pressures, but that this effect was attenuated for higher pressure drops. While
cavity depth effects were minor, reducing depths reduced leakage up to a point beyond
which leakage increased, indicating that an optimum cavity depth existed. Changing
blade spacing produced results almost as significant as those for blade thickness,
showing that reducing spacing can detrimentally affect leakage to the point of negating the benefit of inserting additional blades. Tests to determine the effect of PDS partition
walls showed that they reduce axial leakage. The pressure drop was found to be highest
across the first blade of a seal for low pressure drops, but the pressure drop distribution
became parabolic for high pressure drops with the largest drop across the last blade.
Thirteen leakage equations made up of a base equations, a flow factor, and a kinetic
energy carryover factor were examined. The importance of the carryover coefficient
was made evident and a modified carryover coefficient is suggested. Existing fullypartitioned
PDS models were expanded to accommodate seals of various geometries.
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