159 research outputs found
AAC Royce field pea
No full textAAC Royce is a semi-leafless, green cotyledon field pea (Pisum sativum L.) cultivar developed at Agriculture and Agri-Food Canada, Lacombe Research Centre, Lacombe, Alberta, Canada. It has maturity of 105 days, thousand seed weight of 254 g, and a medium lodging resistance. AAC Royce is resistant to powdery mildew (caused by Erysiphe pisi Syd.), and moderately susceptible to mycosphaerella blight (caused by Mycosphaerella pinodes) and fusarium wilt (caused by Fusarium oxysporum). AAC Royce is adapted to all field growing regions in western Canada.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author
Wireless Communication Networks for Gas Turbine Engine Testing
Get PDFA new trend in the field of Aeronautical Engine Health Monitoring is the implementation of wireless sensor networks (WSNs) for data acquisition and condition monitoring to partially replace heavy and complex wiring harnesses, which limit the versatility of the monitoring process as well as creating practical deployment issues. Using wireless technologies instead of fixed wiring will fuel opportunities for reduced cabling, faster sensor and network deployment, increased data acquisition flexibility and reduced cable maintenance costs. However, embedding wireless technology into an aero engine (even in the ground testing application considered here) presents some very significant challenges, e.g. a harsh environment with a complex RF transmission environment, high sensor density and high data-rate. In this paper we discuss the results of the Wireless Data Acquisition in Gas Turbine Engine Testing (WIDAGATE) project, which aimed to design and simulate such a network to estimate network performance and de-risk the wireless techniques before the deployment
Dissipation and discretization in time marching CFD calculation
Get PDFThis thesis concentrates on accuracy improvements for
an existing software package that solves the three
dimensional Reynolds Averaged Navier-Stokes equations in
rotating coordinates. It is a cell centred explicit time
marching code. Two topics are considered: improvement to
the discretization scheme, and reduction of the artificial
dissipation.
The first topic is the analysis of the straight
averaging process which demonstrates that the process can
result in inconsistency with a skewed grid. An alternative
consistent scheme is proposed which is based upon
quadratic interpolation. Improved accuracy can also be
obtained by modifying the grid or adopting a cell vertex
scheme. The stability of the iterative process is also
shown to depend on the time step.
The reduction of artificial dissipation (second
topic) first considers the role of the so called aspectratio
and velocity functions. These are found to be
limited in influence and a new function is proposed based
upon the local flow gradient. Both two and three
dimensional turbomachinery cases are tested and
improvements demonstrated. In the second part of the
analysis, the eigenvalues of the stability matrix are used
to reduce the dissipation in overdamped regions. Again
this method is applied to various test cases and
improvements demonstrated.
The management part of this Total Technology PhD
Program discusses topics concerned with collaboration and
technology development in the aero engine industry with
particular emphasis on the role of an "emerging"
partner
Gas-path Diagnostics and Prognostics for Aero-engines Using Fuzzy Logic and Time Series Analysis
Get PDFReducing the direct operating-costs is now crucial in order to ensure
competitive advantages for airlines and manufacturers, and so effective
advanced engine-condition monitoring methodologies are necessary. Hence
gas-path diagnostics and prognostics methods are reviewed and the
specifications for such effective tools deduced, together with their pertinent
future prospects.
First, the considerable value that a preliminary observability study adds to the
diagnostics process was recognised. A secure procedure has been devised: it
is capable of (i) the identification of the severity of correlations between any two
of the available measurements, as well as the correlations between any two of
the component changes, (ii) the identification of more complex correlations that
involve more than two changes in performance parameters, and (iii) the
quantification of the quality of the system observability through a pertinent
parameter. This enables comparisons among a significant number of
measurement set selections.
The core of the research is a novel gas-path diagnostics (GPD) method that
uses fuzzy logic in order to provide secure quantification of the gas-path
component faults. A fuzzy diagnostics system was set up for the Rolls-Royce
Trent 800 engine that relies on an extensive statement of fuzzy rules generated
using an engine model to achieve a quantitative solution through a non-linear
approach, which is competent to achieve (i) SFI (single fault isolation) in the
presence of noisy data, (ii) tuning over a known global deterioration level for all
the performance parameters (baseline) computed for the previous flight, (iii)
partial MFI (multiple fault isolation) with up to 2 degraded components (i.e. 4
performance parameters) considerably faulty at the same time, (iv) SFI while
isolating systematic errors in the measurements (biasses). A bias-tolerant
system was devised by means of the NOT logical operator and a new
formulation of the fuzzy rules that includes the location of the bias.
An innovative prognostics framework was devised, which uses ARIMA models
and regression models respectively for short and long term investigations, to
compute forecasts and the associated prediction intervals, which are aimed at
assisting the prognostics decision-making process. This is strictly related to the
diverse business intentions: in this study safety and economic related
applications are investigated. For example, the optimisation of the TBO (time
between overhauls) considering maintenance cost and additional fuel cost due
to the deterioration is studied and the potential cost savings for the operators
highlighted.
HMP 1.1 for performance analysis was developed: it is a health-monitoring andprognostics
framework consisting of three modules that perform respectively
observability study, gas-path diagnostics and prognostics. The substantial
benefits that can be achieved with such a tool, relative to the enhanced
maintenance planning and improved mission scheduling, are discussed in the
thesis via applications to the Trent 800 engine
Mission: Vol. 9, No. 7
Get PDFMission: Vol. 9, No. 7. This issue includes the following articles: Political Profiles in the Churches of Christ by Royce Money, Paul\u27s Attitude Toward Government: A Look at Romans 13 by Roger B. Edrington, You Cannot Serve Two Masters a poem by Patricia Allbritten, From Revolution to Arrival Tracing the Drift by Norman L. Parks, On Whose Terms? The Offense of the Gospel a sermon by James Thompson, I Believe that a Church Should Not Participate in Human Government by Andy T. Ritchie, Jr., Books by the editor, Looking Out, Cross Currents, and Forum
The measurement of near wall flows using pneumatic wedge probes.
Get PDFThe three hole, wedge-type pneumatic pressure probe represents a robust
traverse probe design which is widely used for total and static pressure and yaw angle
measurements in turbomachinery. However, unsteady flows are incorrectly averaged due
to pneumatic meaning errors in the pressure pipes. Wedge probes also fail to measure the
correct static pressure when operating in close proximity to a wall through which the
probe is inserted. Thirdly, the aerodynamic calibration obtained for a wedge-type probe
in a closed wind tunnel differs appreciably from that obtained in an open jet. If not
corrected, these errors will corrupt any calculation of turbomachinery blade row
performance.
In this investigation, the second and third effects described above have been
addressed. A factorial experiment was completed in which the influence of seven
variables on the wall proximity effect was quantified. Flow visualisation studies were
performed to understand the responsible flow mechanisms. Two regions of re-circulating
flow were identified in the probe wake, the structure of which depended on the probe
immersion. Similar re-circulatory flows were resolved from three-dimensional
computational fluid dynamics (CFD) calculations of the flow over a wedge probe. A link
between the probe wake re-circulations and flow over the wedge faces was established.
Based on this understanding of the flow structures, a model was developed from which
the wall proximity effect could be predicted for a given set of conditions.
Wedge probe calibrations were completed in a closed wind tunnel and in two
open jets. Discrepancies in the static pressure coefficient and yaw angle sensitivity results
were found. These were partially explained in terms of modifications to the probe wake
structure which occurred when the probes were calibrated in the open jet facilities.
Procedures for correcting the wall proximity effect and for avoiding the facility
dependence of wedge probe calibrations were developed from this understanding of the
flow mechanisms involved.
Based on the findings of this investigation, a novel wedge probe was designed to
minimise the wall proximity effect. This probe demonstrated a reduction in the wall
proximity effect, from 20% dynamic head with current designs, to 3% dynamic head at
flows typical of high speed turbomachinery
Structurally Integrated Slotless PM Brushless Motor with Spiral Wound Laminations for Marine Thrusters
No full textRim driven thrusters with structurally integrated brushless PM motors are now an established technology with an increasing range of applications. In these thrusters, the stator of the motor is housed within the thruster duct, and the rotor forms a ring around the tips of the propeller. Such high pole number motors tend to be very thin radialy, have very small length to diameter ratios, and have relatively large airgaps to accommodate corrosion protection layers on the surfaces of the rotor and stator. The relatively large diameter stator laminations of such machines tend therefore to have very thin back of core and narrow teeth, which make them expensive and difficult to manufacture. This paper proposes an alternative potentially lower cost motor topology featuring a slotless stator whose laminations are manufactured from a single strip of steel that is edge wound into a spiral (like a “slinky” and then fitted over the windings that are preformed on the outside surface of a non-conducting former. The former is also part of the sealed housing that protects the stator from corrosion in seawater. The paper discusses the design optimisation of such a motor using analytical and finite element analysis (FEA), describes a demonstrator motor and reports experimental and FEA results
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Fourteen fabulous acrostic bibliophiles
No full textAcrostics based on the names of 14 friends of the author, and his own. The title page and colophon are also written as acrostics also.
The people are: Robert E. Massmann; Samuel E. Murray; J.N.B. Artfield; Ruth E. adomeit; F. J. Board; Glen Dawson; A. J. St. Onge; Julia P. Wightman; Eugene D. Buchanan; Francis J. Gagiardi; Royce L. Gale Jr.; Philip Bliss; Julian I. Edison; and Raymond A. Smith
Numerical modelling of viscous turbomachinery flows with a pressure correction method
Get PDFA fully elliptic computational method for the analysis of steady viscous flow
in high speed subsonic centrifugal compressor impellers with tip leakage, is
presented. A generalised curvilinear, non-orthogonal grid is utilised and the timeaveraged
Navier-Stokes equations are transformed and expressed in a fully
conservative form. The discretisation of the governing equations is performed
through finite volume integration. The solution procedure employs a non-staggered
variable arrangement and a SIMPLE based method for coupling the velocity and
pressure fields. The turbulence effects are simulated with the use of the k-e model,
modified to account for rotation and streamline curvature, and the near-wall viscous
phenomena are modelled through the wall function method.
The numerical model is implemented for the flow prediction in a series of
two and three dimensional test cases. Incompressible flow predictions in twodimensional
cascades and three-dimensional ducting systems with different
geometrical features and inlet conditions are initially performed and the numerical
results are compared against available experimental data. The final objective of the
present study is achieved through the comparative study of the predictions obtained
against the results of Eckardt's experimental investigation of the viscous
compressible flow in a high speed radial impeller operating at design condition and
in a backswept impeller at design and off-design conditions. In addition, the flow is
simulated in the passages of the Rolls Royce GEM impeller which was tested at
Cranfield at design and off-design flow rates.
A jet/wake pattern was discerned in all the simulated centrifugal compressor
cases and a good overall agreement was achieved with the measured wake formation
and development; and, encouraging results were obtained on the evolution of the
secondary flows. The tip leakage effects influenced the loss distribution, the size and
the location of the wake flow pattern at the rotor exit. The effects of the flow mass
rate on the detailed flow pattern and on the compressor performance have been well
represented. In certain cases, the quality of the present predictions is an
improvement over that obtained by other "state-of-the-art" Navier-Stokes solvers.
In conclusion, the developed finite volume flow model has captured a large number
of complex flow phenomena encountered in the tested impellers and is expected to
provide a useful aerodynamic analysis tool for stationary or rotating, axial or radial
turbomachinery components
High Frequency and Amplitude Effects in Vibratory Media Finishing
No full textAbstractThe vibratory media finishing process is known for its long process time and there is an industrial need to speed up this process. Increasing frequency and amplitude of vibration, beyond the current process window commonly used, is an option to reduce process time. Using a laboratory scale electro-magnetic shaker setup, the effects of increasing frequency and amplitude of vibration is investigated. By monitoring the surface roughness with processing time it is shown that, while for a given amplitude frequency has a strong effect, amplitude in general has a stronger effect in quickening the time to saturation. Using high-speed camera measurements in a transparent bowl it is also shown that the average media speed increases with increase in frequency and this can partially explain the resulting shorter process time
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