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Viewing 1 to 24 of 24
2011-06-13
Technical Paper
2011-38-0073
Anthony P. Brown
Data is presented from a number of flight research aircraft, which have been involved in the research of the effects of inflight icing, in a variety of atmospheric supercooled droplet and mixed-phase icing environmental conditions. The aircraft Types considered cover both Pneumatic and Thermal Ice Protection Systems (IPS). Icing includes supercooled droplet impact icing upon airframe and propeller blades and cold-soaked frost icing. The drag effects of inflight icing, from mixed-phase small and large droplets encountered during the course of SALPEX cloud physics research operations, upon a Fokker F-27 turboprop transport aircraft, have been analyzed. Furthermore, during the course of AIRS 1.5 and AIRS II inflight icing flight research operations, the NRC Convair conducted aerodynamic characterization maneuvers, following and during icing accretion in a wide range of environmental conditions of altitude, air temperature, LWC and droplet spectra.
2001-09-11
Technical Paper
2001-01-2965
Kenneth Hui, Carl Swail, Barrie Leach
The Flight Research Laboratory (FRL), National Research Council (NRC) of Canada is currently developing an in-flight aircraft aerodynamic model identification technique that determines the small perturbation model at a given test condition. Initial demonstrations have been carried out using the NRC Falcon 20 research aircraft. An efficient system architecture, in terms of both software algorithms and hardware processing, has been designed to meet the stringent near real-time requirements of an in-flight system. As well, novel hardware and software techniques are being applied to the calibration and measurement of the fundamental in-flight parameters, such as air data. The small perturbation models are then combined to develop a global model of the aircraft that is validated by comparing the model response to flight data. The maneuvers were performed according to the FAA Acceptance Test Guide (ATG).
2010-06-08
Article
The Boeing Co. and Canadian industry partners have launched a new research and development consortium aimed at strengthening Canada's position in the manufacturing of advanced composite materials for aerospace and other industries.
2013-10-25
Article
Carbon-fiber-reinforced thermoset composites continue to be difficult to recycle, as they are a complex mixture of different materials such as thermosetting polymers, carbon fibers, and fillers. Researchers from the Universite Du Quebec at Montreal, Bell Helicopter Textron Canada, and the National Research Council Canada investigated using carded recycled carbon-fiber mats and epoxy resin to fabricate thermoset composite plates.
2016-09-27
Technical Paper
2016-01-8143
Jerry Syms, Theresia Manns, Björn Bergqvist
Abstract The noise generated by the flow of air past a transport truck is a key design factor for the manufacturers of these vehicles as the sound levels in the cabin are a significant component of driver comfort. This paper describes a collaboration between Volvo GTT and the National Research Council Canada to measure the in-cabin aeroacoustics of a full-scale cab-over tractor in the NRC 9 m Wind Tunnel. Acoustic instrumentation was installed inside the tractor to record cabin noise levels and externally to acquire tunnel background noise data. Using a microphone mounted on the driver’s-side tunnel wall as a reference to remove variations in background noise levels between data points, differences in cabin noise levels were able to be detected when comparing the tractor with different configurations. The good repeatability of the data allowed for differences of as little as 0.5 dB to be measured.
2015-06-15
Technical Paper
2015-01-2125
Dan Fuleki, Jennifer L.Y. Chalmers, Brian Galeote
This paper describes the equipment, analysis methods and results obtained for particle size measurements based on a particle imaging velocimetry (PIV) system in which a short duration laser pulse is used to backlight airborne particles. This produces high quality and high resolution images of fast moving airborne particles in a non-intrusive manner. This imaging technique is also used to examine particle morphology and 2D particle trajectory and velocity. The image analysis methods are outlined and validation test results discussed which show the measurement of reference glass beads between 20 and 400 microns were generally to within their stated size. As well, validation testing using known icing wind tunnel droplet distributions were compared with Spraytek 2000 Malvern droplet size measurements and showed agreement of the MVD's to be within ±5% for distributions having nominally 20, 40 and 80 micron MVD's.
2015-06-15
Technical Paper
2015-01-2116
Peter Struk, Tadas Bartkus, Jen-Ching Tsao, Tom Currie, Dan Fuleki
Abstract This paper presents measurements of ice accretion shape and surface temperature from ice-crystal icing experiments conducted jointly by the National Aeronautics and Space Administration (NASA) and the National Research Council (NRC) of Canada. The data comes from experiments performed at NRC's Research Altitude Test Facility (RATFac) in 2012. The measurements are intended to help develop models of the ice-crystal icing phenomenon associated with engine ice-crystal icing. Ice accretion tests were conducted using two different airfoil models (a NACA 0012 and wedge) at different velocities, temperatures, and pressures although only a limited set of permutations were tested. The wedge airfoil had several tests during which its surface was actively cooled. The ice accretion measurements included leading-edge thickness for both airfoils. The wedge and one case from the NACA 0012 model also included 2D cross-section profile shapes.
2015-06-15
Technical Paper
2015-01-2162
Krzysztof Szilder, Edward Lozowski
Abstract We have developed an original, three-dimensional icing modelling capability, called the “morphogenetic” approach, based on a discrete formulation and simulation of ice formation physics. Morphogenetic icing modelling improves on existing ice accretion models, in that it is capable of predicting simultaneous rime and glaze ice accretions and ice accretions with variable density and complex geometries. The objective of this paper is to show preliminary results of simulating complex three-dimensional features such as lobster tails and rime feathers forming on a swept wing. The results are encouraging. They show that the morphogenetic approach can predict realistically both the overall size and detailed structure of the ice accretion forming on a swept wing. Under cold ambient conditions, when drops freeze instantly upon impingement, the numerical ice structure has voids, which reduce its density.
2011-10-18
Technical Paper
2011-01-2572
Krzysztof Szilder, Stuart McIlwain
The intensive deployment of UAVs for surveillance and reconnaissance missions during the last couple of decades has revealed their vulnerability to icing conditions. At present, a common icing avoidance strategy is simply not to fly when icing is forecast. Consequently, UAV missions in cold seasons and cold regions can be delayed for days when icing conditions persist. While this approach limits substantially the failure of UAV missions as a result of icing, there is obviously a need to develop all-weather capabilities. A key step in accomplishing this objective is to understand better the influence of a smaller geometry and a lower speed on the ice accretion process, relative to the extensively researched area of in-flight icing for traditional aircraft configurations characterized by high Reynolds number. Our analysis of the influence of Reynolds number on the ice accretion process is performed for the NACA0012 airfoil.
2013-09-17
Journal Article
2013-01-2307
Paul Lebbin
This paper presents a review of the flight deck and cabin fire and smoke incidents reported to the Canadian airworthiness authorities over a ten year span. The fire and smoke related diversions are categorized to identify areas where efforts could be increased to improve safety. The costs of diversions are estimated to identify areas where operators could reduce costs by seeking technologies to reduce the number of diversions without any impact on safety. Only twenty-eight investigation reports into fire and smoke incidents onboard aircraft have been published over the past three decades. These reports are not sufficient to identify areas where operators can reduce their operating costs. The Canadian airworthiness authorities received over 1,000 smoke and fire incidents from the years 2001 to 2010, of which, over 680 reported fire and smoke in the flight deck and cabin compartments for various makes and models of aircraft.
2011-10-18
Journal Article
2011-01-2651
Jason Michel Lambert, Martin De Montigny, Claude Perron
This paper examines issues related to planning, programming and execution of machining operations by a robot in the context of machining large parts with complex geometries by a gantry-mounted robotic system. Parts were created from surface data in a CAD/CAM environment. The same environment was used to generate tool paths using a conventional machine tool approach. These paths were converted to robot trajectories and validated using mathematical kinematic models of the robotic system. Validation was performed according to various criteria related to process performance. Associated robot programs were then automatically generated. The manufacturing cell was progressively integrated according to requirements resulting from iterative process characterization. A metrology-based calibration procedure was designed that considerably improved the system's positioning precision.
2013-09-17
Technical Paper
2013-01-2131
Tak W. Chan, Vinh Pham, Jennifer Chalmers, Craig Davison, Wajid Chishty, Pierre Poitras
Adoption of hydro-processed esters and fatty acid biojet fuels is a critical component for the sustainability of the aviation industry. Aviation biofuels reduce pollution and provide alternatives to conventional fossil fuels. A study of the impacts of biofuels on emissions from a T56 turbo-prop engine was undertaken as a joint effort among several departments of the Government of Canada. In this study, particulate (including particle number and black carbon (BC) mass) and regulated gaseous emissions (CO2, CO, NO, NO2, THC) were characterized with the engine operating on conventional F-34 jet fuel and jet fuel blended with camelina-based hydro-processed biojet fuel (C-HEFA) by 50% in volume. Emissions characterization, conducted after 20-hour ground engine durability tests, showed immediate significant reductions in particle number and BC mass when the engine was operated on the C-HEFA blend.
2015-06-15
Technical Paper
2015-01-2107
Tom Currie, Dan Fuleki, Craig Davison
Abstract Ice crystals ingested by a jet engine at high altitude can partially melt and then accrete within the compressor, potentially causing performance loss, damage and/or flameout. Several studies of this ice crystal icing (ICI) phenomenon conducted in the RATFac (Research Altitude Test Facility) altitude chamber at the National Research Council of Canada (NRCC) have shown that liquid water is required for accretion. CFD-based tools for ICI must therefore be capable of predicting particle melting due to heat transfer from the air warmed by compression and possibly also due to impact with warm surfaces. This paper describes CFD simulations of particle melting and evaporation in the RATFac icing tunnel for the former mechanism, conducted using a Lagrangian particle tracking model combined with a stochastic random walk approach to simulate turbulent dispersion. Inter-phase coupling of heat and mass transfer is achieved with the particle source-in-cell method.
2015-09-15
Journal Article
2015-01-2562
Tak W. Chan, Wajid Chishty, Craig Davison, David Buote
Abstract This study reports gaseous and particle (ultrafine and black carbon (BC)) emissions from a turbofan engine core on standard Jet A-1 and three alternative fuels, including 100% hydrothermolysis synthetic kerosene with aromatics (CH-SKA), 50% Hydro-processed Esters and Fatty Acid paraffinic kerosene (HEFA-SPK), and 100% Fischer Tropsch (FT-SPK). Gaseous emissions from this engine for various fuels were similar but significant differences in particle emissions were observed. During the idle condition, it was observed that the non-refractory mass fraction in the emitted particles were higher than during higher engine load condition. This observation is consistent for all test fuels. The 100% CH-SKA fuel was found to have noticeable reductions in BC emissions when compared to Jet A-1 by 28-38% by different BC instruments (and 7% in refractory particle number (PN) emissions) at take-off condition.
2011-06-13
Technical Paper
2011-38-0099
James MacLeod, John Jastremski
The Global Aerospace Centre for Icing and Environmental Research (GLACIER) facility has been constructed in Thompson, Manitoba, Canada. This project involves the construction and operation of a facility which will provide icing certification tests for large gas turbine engines, as well as performance, endurance and other gas turbine engine qualification testing. MDS Aero Support, in partnership with the National Research Council of Canada (NRC), Pratt and Whitney Canada, and Rolls Royce Canada, has developed a globally unique outdoor engine test and certification facility. The prime purpose of this facility is for icing certification of aviation gas turbine engines, initially for Rolls-Royce and Pratt & Whitney, two of the three largest gas turbine manufacturers in the world.
2011-06-13
Technical Paper
2011-38-0036
Craig Davison, Thomas Ratvasky, Lyle Lilie
A total water content probe for flight- and ground-based testing is being completed. During operation across a range of altitudes and water content conditions, the probe has to maintain isokinetic flow, vaporize the solid and liquid water content and maintain the inlet ice free to ensure isokinetic flow. Despite achieving isokinetic operation, the collection efficiency of particles less than 30 μm can be less than 100%. A correlation of collection efficiency to Stokes number has been determined to correct the results for this effect. In preparation for flight testing an integrated data acquisition, control and power supply unit was developed and successfully tested. Results from testing at the NASA Glenn Icing Research Tunnel are presented covering both ice crystals and super-cooled liquid conditions. The results correspond well to previously published work and problems encountered during previous testing of this probe are shown to have been resolved.
2011-06-13
Technical Paper
2011-38-0018
Peter Struk, Tom Currie, William Benjamin Wright, Daniel C. Knezevici, Dan Fuleki, Andy Broeren, Mario Vargas, Jen-Ching Tsao
Due to numerous engine power-loss events associated with high-altitude convective weather, ice accretion within an engine due to ice-crystal ingestion is being investigated. The National Aeronautics and Space Administration (NASA) and the National Research Council (NRC) of Canada are starting to examine the physical mechanisms of ice accretion on surfaces exposed to ice-crystal and mixed-phase conditions. In November 2010, two weeks of testing occurred at the NRC Research Altitude Facility utilizing a single wedge-type airfoil designed to facilitate fundamental studies while retaining critical features of a compressor stator blade or guide vane. The airfoil was placed in the NRC cascade wind tunnel for both aerodynamic and icing tests. Aerodynamic testing showed excellent agreement compared with CFD data on the icing pressure surface and allowed calculation of heat transfer coefficients at various airfoil locations.
2011-10-18
Technical Paper
2011-01-2597
Tak W. Chan, Kevin Cuddihy, Wajid Chishty, Craig Davison, Mark McCurdy, Peter Barton
Gaseous and particle emission assessments on a 1.15 kN-thrust turbojet engine were conducted at five altitudes in an altitude chamber with Jet A-1 fuel, pure Fischer Tropsch (FT), and two mixed fuels of JP-8 with FT or Camelina-based hydro-processed jet fuels. In general, lower emissions in CO₂, NOx, and particle number as well as higher emissions in CO and THC were observed at higher altitudes compared to lower altitudes. These observations, which were similar for all test fuels, were attributed to the reduced combustion efficiency and temperature at higher altitudes. The use of alternative fuels resulted in lower CO₂ emissions, ranging from 0.7% to 1.7% for 50% to 100% synthetic fuel in the fuel mixture at various altitudes. In terms of CO, the use of 100% FT fuel resulted in CO reduction up to 9.7% at 1525 m altitude and up to 5.9% at 9145 m altitude.
2013-09-17
Technical Paper
2013-01-2208
Stefan Andjelic, Judith Roberge, Nathalie Legros, Lolei Khoun, Steen Brian Schougaard
The use of carbon fiber reinforced thermoset composites has doubled in the last decade raising questions about the waste generated from manufacturing and at end-of-life, especially in the aircraft industry. In this study, 2.5 cm long carbon fibers were recovered from thermoset composite waste using a commercial scale pyrolysis process. Scanning electron microscopy, density measurements, single filament tensile testing as well as micro-droplet testing were performed to characterize the morphology, mechanical properties, and surface adhesion of the fibers. The recycled fibers appeared to be mostly undamaged and clean, exhibiting comparable mechanical properties to virgin carbon fibers. A carding process followed by an ultrasound treatment produced randomly aligned recycled fiber mats. These mats were used to fabricate composite plates, with fiber volume fractions up to 40 %, by infusion / compression molding.
2015-06-15
Technical Paper
2015-01-2134
Tom Currie, Dan Fuleki
Abstract Ice crystals ingested by a jet engine at high altitude can partially melt and then accrete within the forward stages of the compressor, potentially causing performance loss, damage and/or flameout. Recent research into this ice crystal icing (ICI) phenomenon conducted at the National Research Council of Canada suggests that the liquid water content vliq of an accretion significantly affects the accretion's susceptibility to erosion by ice crystals, and therefore accretion growth. This paper describes the development and application of an instrument for measuring vliq, potentially providing a method for correlating erosion behavior (e.g. as ductile or brittle) and properties. The instrument measures the complex admittance Y* of a mixed-phase deposit bridging a pair of electrodes, which is modeled as a resistor and capacitor in parallel, and calculates the deposit's relative permittivity εr from the capacitance.
2015-06-15
Technical Paper
2015-01-2092
David M. Orchard, Catherine Clark, Myron Oleskiw
Abstract Simulations of supercooled large droplet (SLD) icing environments within the NRC's Altitude Icing Wind Tunnel (AIWT) have been performed in which broad band mass distribution spectra are achieved that include a distinct pattern of liquid water content (LWC) over a range of droplet sizes (i.e., bi-modal distribution). The mass distribution is achieved through modification of the existing spray system of the AIWT to allow two spray profiles with differing LWC and median volumetric diameter (MVD) to be simultaneously injected into the flow. Results of spray profile distributions measured in the test section have demonstrated that freezing drizzle conditions, where MVD is either less than or greater than 40 μm, can be achieved.
2002-11-05
Technical Paper
2002-01-2916
Kenneth Hui, Joseph Ricciardi, Ramesh Srinivasan, Edward Lambert, Ara Sarafian
A joint program between Bell Helicopter Textron Canada and the Flight Research Laboratory of Canada's National Research Council was initiated to address the aerodynamic modelling challenges of the Bell M427 helicopter. The primary objective was to use the NRC parameter estimation technique, based on modified maximum likelihood estimation (MMLE), on a limited set of flight test data to efficiently develop an accurate forward-flight mathematical model of the Bell M427. The effect of main rotor design changes on the aircraft stability characteristics was also investigated, using parameter estimation. This program has demonstrated the feasibility of creating a forward-flight rotorcraft aerodynamic mathematical model based on time-domain parameter estimation, and the ability of a 6 degree-of-freedom MMLE model to accurately document the impact of minor rotor modifications on aircraft stability.
2011-06-13
Technical Paper
2011-38-0079
Daniel C. Knezevici, Dan Fuleki, James MacLeod
This paper describes the commissioning of a linear compressor cascade rig for ice crystal research. The rig is located in an altitude chamber so the test section stagnation pressure, temperature and Mach number can be varied independently. The facility is open-circuit which eliminates the possibility of recirculating ice crystals reentering the test section and modifying the median mass diameter and total water content in time. As this is an innovative facility, the operating procedures and instrumentation used are discussed. Sample flow quality data are presented showing the distribution of velocity, temperature, turbulence intensity and ice water concentration in the test section. The control and repeatability of experimental parameters is also discussed.
1999-10-19
Technical Paper
1999-01-5529
N. C. Bellinger, R. W. Gould, J. P. Komorowski
The National Research Council Canada has collected a large number of corroded and non-corroded fuselage lap joints from retired and operational aircraft. A number of these corroded joints have been disassembled in order to quantify the level of corrosion. During the disassembly, it was often observed that common repair techniques resulted in damage to the structure. The damage observed was significant enough to raise concerns regarding the effect of the repair techniques on structural integrity. This paper describes the different types of damage found.
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