Display:

Results

Viewing 91 to 120 of 23660
2015-06-15
Technical Paper
2015-01-2347
James A. Mynderse, Alexander Sandstrom, Zhaohui Sun
Abstract The American Axle & Manufacturing Inc. driveline dynamometer provides immense value for experimental validation of product NVH performances. It has been intensively used to evaluate product design robustness in terms of build variations, mileage accumulation, and temperature sensitivity. The current driveline dynamometer input motor system has multiple torsional modes which create strong coupling with test part gear mesh dynamics. Mechanical Engineering seniors at Lawrence Technological University designed, fabricated, and validated a mechanism to decouple the driveline dynamics from the driveline dynamometer dynamics. The student-designed decoupler mechanism is presented with experimental validation of effectiveness in decoupling driveline dynamometer dynamics from the driveline under test.
2015-06-15
Technical Paper
2015-01-2348
Richard Kolano
Abstract This paper presents the results of a study to reduce the background noise level within a large Quiet Room located adjacent to other laboratory testing environments and below a mechanical mezzanine which houses an extensive array of mechanical and electrical equipment including banks of low-temperature chiller compressors, air handling units, and electrical switchgear that serves the entire building complex. This equipment was installed atop the concrete mezzanine floor deck without provisions for isolating vibration. As a result, structure-borne noise from that equipment travels through the floor, radiates from the underside of the floor deck, and intrudes into the Quiet Room below. This causes the background noise level within the Quiet Room to be too high for conducting low sound level measurements and studies on vehicles brought into the Quiet Room.
2015-06-15
Technical Paper
2015-01-2346
Balakumar Swaminathan
Abstract From a facility perspective, engine test cells are rarely evaluated for their vibration levels in their functional configuration. When complicated dynamic systems such as an internal combustion engine and a dynamometer are coupled together using driveshafts and coupling components, the overall system behavior is significantly different from that of the individual sub-systems. This paper details an instance where system level experimental testing and finite element analysis methods were used to mitigate high vibration levels in an engine test cell. Modal and operational test data were taken to establish baseline vibration levels at a diesel engine test cell during commissioning. Measurements were taken on all major sub-systems such as the engine assembly, dynamometer assembly, intermediate driveshaft bearing pedestal and driveshaft components.
2015-06-15
Technical Paper
2015-01-2187
Mark A. Gehringer, Keith Thompson
Abstract This paper describes the development of a semi-automated end-of-line driveline system balance tester for an automotive assembly plant. The overall objective was to provide final quality assurance for acceptable driveline noise and vibration refinement in a rear wheel drive vehicle. The problem to be solved was how to measure the driveline system unbalance within assembly plant constraints including cycle time, operator capability, and integration with a pre-existing vehicle roll test machine. Several challenging aspects of the tester design and development are presented and solutions to these challenges are addressed. Major design aspects addressed included non-contacting vibration sensing, data acquisition/processing system and vehicle position feedback.
2015-06-15
Technical Paper
2015-01-2213
John Van Baren
Abstract Random vibration control systems produce a PSD plot by averaging FFTs. Modern controllers can set the Degrees of Freedom (DOF), which is a measure of the amount of averaging to use to estimate the PSD. The PSD is a way to present a random signal-which by nature “bounces” about the mean, at times making high excursions from the mean-in a format that makes it easy to determine the validity of a test. This process takes time as many frames of data are collected in order to generate the PSD estimate, and a test can appear to be out of tolerance until the controller has enough data to estimate the PSD with a sufficient level of confidence. Something is awry with a PSD estimate that achieves total in-tolerance immediately after starting or during level changes, and this can create dangerous over or under test conditions within specific frequency bands and should be avoided.
2015-06-15
Technical Paper
2015-01-2118
Sergey Alekseyenko, Michael Sinapius, Martin Schulz, Oleksandr Prykhodko
Abstract The results of experimental investigation of the icing processes of NACA 0015 airfoil are presented. The experiments have been carried out with the help of a high-speed camera at the icing/deicing facility at the Institute of Adaptronic and Functional Integration of the Technical University of Braunschweig. The investigation objective is the study of interaction between supercooled large droplets and the icing airfoil surface as well as physical phenomena occurring during the icing process. Evolution of the initial phase of ice growth process over time is observed, the general structure of ice accretion and its alteration along the airfoil is examined. Experiments have been carried out within a wide temperature range. Photos of the specific moments of the icing process have been analyzed. Splashing events and water movement on the icing surface have been observed.
2015-06-15
Technical Paper
2015-01-2110
Jozef Brzeczek, Janusz Pietruszka, Robert J. Flemming, Ben C. Bernstein
Abstract In 2014 PZL Mielec obtained an EASA Type Certificate extension for the PZL M28 05 airplane for flight into icing conditions and this has been validated by the FAA. Thus, a project that lasted four years was finished successfully. During this period, activities consisted of icing analyses, wind tunnel tests in the NASA Glenn Research Center Icing Research Tunnel, and natural icing flight tests, artificial icing flight tests, flight tests with simulated ice shapes, and calibration tests. Flights in measured natural icing conditions began during the spring of 2009 and certification flight tests were performed in 2012. The natural icing test flights, apart one flight in the USA, were performed in Poland in the Mielec area. The final test campaign can be divided into two phases: (1) March -April flight tests campaign; and (2) November - December flight test campaign, the latter after introducing some design changes in airframe ice protection system.
2015-06-15
Technical Paper
2015-01-2111
Marie-Laure Toulouse, Richard Lewis
Abstract The intent of this paper is to provide a general overview of the main engineering and test activities conducted in order to support A350XWB Ice and Rain Protection Systems certification. Several means of compliance have been used to demonstrate compliance with applicable Certification Basis (CS 25 at Amendment 8 + CS 25.795 at Amendment 9, FAR 25 up to Amendment 129) and Environmental protection requirements. The EASA Type Certificate for the A350XWB was received the 30th September 2014 after 7 years of development and verification that the design performs as required, with five A350XWB test aircraft accumulating more than 2600 flight test hours and over 600 flights. The flight tests were performed in dry air and measured natural icing conditions to demonstrate the performance of all ice and rain protection systems and to support the compliance demonstration with CS 25.1419 and CS25.21g.
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
2015-01-2128
Enrico Bellussi
Abstract This paper describes the AgustaWestland (AW) experience in the use of the results obtained with the HISS flight tests to support the civil ice clearance for rotorcraft. The use of the HISS, a US Army CH-47D Chinook fitted with a spray bar system providing a cloud where the helicopter can fly in icing conditions, allows stable and prolonged flight data, conditions extremely difficult to encounter during natural ice flights. The paper analyses the definition of the HISS test matrix, to optimize the points needed for system development and the points possibly usable during certification, in both normal and failure mode conditions. It is also shown how the HISS ice campaigns results can be assessed, and how they can be compared to the natural ice flights to validate them. Finally it is explained how the HISS results can be used, in addition to natural ice flights results, to support the certification.
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
2015-01-2147
Sandra Turner, Jean-Marc Gaubert, Remy Gallois, Thibault Dacla, Ingrid Mullie, Aurelien Bourdon, Fabien Dezitter, Alice Grandin, Alain Protat, Rodney Potts, Alfons Schwarzenboeck, J. Walter Strapp
Abstract The PLANET System was used for real-time satellite data transmission during the HAIC-HIWC Darwin field campaign (January to March 2014). The basic system was initially providing aircraft tracking, chat, weather text messages (METAR, TAF, etc.), and aeronautical information (NOTAMs) in a standalone application. In the framework of the HAIC project, many improvements were made in order to fulfill requirements of the onboard and ground science teams for the field campaign. The aim of this paper is to present the main improvements of the system that were implemented for the Darwin field campaign. New features of the system are related to the hardware component, the communication protocol, weather and tracking display, geomarkers on the map, and image processing and compression before onboard transfer.
2015-06-15
Technical Paper
2015-01-2144
James MacLeod, Michael Clarke, Doug Marsh
The Global Aerospace Centre for Icing and Environmental Research Inc. (GLACIER) facility is located in Thompson, Manitoba, Canada. This facility provides icing certification tests for large gas turbine engines, as well as performance, endurance and other gas turbine engine qualification testing. This globally unique outdoor engine test and certification facility was officially opened back in 2010. The prime purpose of this facility is for icing certification of aero gas turbines. As a generic engine test facility, it includes the infrastructure and test systems necessary for the installation of both current and future gas turbine engines. The GLACIER facility completed its commissioning in the winter of 2010/2011, and has now experienced five years of full icing seasons. Rolls-Royce and Pratt and Whitney have both successfully performed certification and engineering icing testing with 5 engines completing their icing certification.
2015-06-15
Technical Paper
2015-01-2142
Colin Hatch, Roger Gent, Richard Moser
Abstract Low power ice protection systems are an important research area that is highlighted in the EU Clean Sky programme. In this paper an icing wind tunnel test of a full-scale wing incorporating both an electro-thermal and a hybrid electro-thermal electro-mechanical system is described. A description of a software tool to analyse both systems as full 3D models is also given. Preliminary comparisons of test data and prediction are shown both for the electro-thermal system and the hybrid system. Initial comparisons show a reasonable correlation in the main with recommendations for a structure tear-down to identify exact internal transducer locations. Recommendations are also made with regard to undertaking tests to determine a more consistent set of mechanical failure properties of ice. Future work in the development of the tool is also discussed.
2015-06-15
Technical Paper
2015-01-2143
Christian Mendig
Abstract In the project SuLaDI (Supercooled Large Droplet Icing) research about the icing of aerofoils through large and super cooled droplets is done at the Institute of Composite Structures and Adaptive Systems (German Aerospace Center-DLR) and at the Institute of Adaptronics and Function Integration (Technische Universität Braunschweig). In the framework of the project an icing wind tunnel was built. It consists of a cooling chamber and a wind tunnel of the Eiffel-type therein. The icing of model takes place in the test section of the wind tunnel at temperatures below 0 °C. Between the flow straightener and the contraction section a spray system is built in, which sprays water droplets into the wind tunnel. The droplets are accelerated by the airstream and supercool on their way to the model. When hitting the model they freeze on it to rime ice, clear ice or mixed ice. At the model research about a structure integrated ice detection is done.
2015-06-15
Technical Paper
2015-01-2247
Masao Nagamatsu
Abstract The sound localization methods are used for detection of noise source locations of prototypes of mechanical products including automobile engines. There are several types of sound localization methods. In middle frequency around 1kHz, which is most sensitive frequency for human auditory, these sound localization methods have enough resolution in their reconstructed images, and they are effective to localize the sound sources. For high frequency sound localization, the holographic type methods take long time in its measurement. To overcome this problem, I have developed a converted method of Nearfield Acoustic Holography (NAH) method, which is one of conventional holographic sound localization method. However, in low frequency, all holographic localization methods do not have enough resolution in reconstructed images. I am now developing new sound localization method, Double Nearfield Acoustic Holography (DNAH) method.
2015-06-15
Technical Paper
2015-01-2292
Xiaorui Lu, Junda Ma
Abstract Over recent years, NVH refinement of engine is becoming increasingly important in buying decision and can significantly give competitive edge to the vehicle in market place. This paper deals with the development phase of a prototype engine in which a specific testing activity was carried out to improve the overall NVH behavior of the powertrain. In order to explain the optimization process in detail, a case study was described in this paper. First, NVH targets of the engine were set via benchmark tests on existing competitive products. Then series of baseline tests, such as 1M sound pressure level test and noise source identification, were performed on the engine. Test results indicated that an obvious breathing vibration mode exist near the intake manifold, which radiates high level noise. In order to achieve the NVH targets, a correlation validation was performed to find out the main reason that caused the vibration of intake manifold.
2015-06-15
Technical Paper
2015-01-2299
Dhanesh Purekar
Abstract NVH development of light duty diesel engines require significant collaboration with the OEM as compared to medium duty and heavy duty diesel engines. Typically, competitive benchmark studies and customer expectations define the NVH targets at the vehicle level and are subsequently cascaded down to the powertrain level. For engine manufacturing companies like Cummins Inc., it is imperative to work closely with OEM to deliver on the NVH expectations. In certain situations, engine level NVH targets needs to be demonstrated in the OEM or 3rd party acoustic test facility for customer satisfaction or commercial purposes. Engine noise tests across different noise test facilities may introduce some variation due to differences in the acoustic test facilities, test hardware, instrumentation differences, etc. In addition, the engine itself is a major source of variation.
2015-06-15
Technical Paper
2015-01-2278
Rohit Ravindran, Debajit Das, Keval Kamani, P Sivaraman, Gyan Arora
Abstract Torsional vibration is a characteristic phenomenon of automotive powertrains. It can have an adverse impact on powertrain related noise as well as the durability of transmission and drivetrain components. Hence minimizing torsional vibration levels associated with powertrains has become important. In this context, accurate measurement and representation of angular acceleration is of paramount importance. A methodology was developed for in-house vehicle level torsional vibration measurement, analysis and representation of results. The evaluation of torsional vibration has two major aspects. First, the acquisition of raw rotational data and secondly, the processing of acquired data to arrive at usable information from which inferences and interpretations can be made about the behavior of the rotating element. This paper describes the development process followed for establishing a torsional vibration evaluation methodology.
2015-06-15
Journal Article
2015-01-2281
Shrirang Deshpande, Randall Allemang
Abstract Spectral maps and order tracks are tools which are susceptible to improper sensor location on rotating machinery and to measurement noise. On a complex/large rotating system, the major behavior in a particular direction cannot be observed by using standard digital signal processing averaging techniques on different sensor outputs. Also, measurement noise cannot be reduced by applying averaging - due to the slew rate of the system. A newly developed technique tested on experimental data, is presented which uses singular value decomposition (SVD) as its basis to improve the observability of rotating systems. By using data acquired from multiple accelerometers on a machine, singular values - obtained from a SVD of the cross-power matrix at each 2-D point in the frequency-RPM domain - can be plotted in a color-map format similar to a RPM spectral map.
2015-06-15
Journal Article
2015-01-2284
Chris Hocking, Simon Antonov, Arsham Shahlari
Abstract The higher cylinder peak pressure and pressure rise rate of modern diesel and gasoline fueled engines tend to increase combustion noise while customers demand lower noise. The multiple degrees of freedom in engine control and calibration mean there is more scope to influence combustion noise but this must first be measured before it can be balanced with other attributes. An efficient means to realize this is to calculate combustion noise from the in-cylinder pressure measurements that are routinely acquired as part of the engine development process. This publication reviews the techniques required to ensure accurate and precise combustion noise measurements. First, the dynamic range must be maximized by using an analogue to digital converter with sufficient number of bits and selecting an appropriate range in the test equipment.
2015-06-15
Technical Paper
2015-01-2246
Kurt Veggeberg, Mike Denton
Abstract This is an overview of the development of a portable, real-time acoustic beamformer based on FPGA (Field Programmable Gate Arrays) and digital microphones for noise source identification. Microphone arrays can be a useful tool in identifying noise sources and give designers an image of noise distribution. The beamforming algorithm is a classic and efficient algorithm for signal processing of microphone arrays and is the core of many microphone array systems. High-speed real-time beamforming has not been implemented much in a portable instrument because it requires large computational resources. Utilizing a beamforming algorithm running on a Field Programmable Gate Array (FPGA), this camera is able to detect and locate both stationary and moving noise sources. A high-resolution optical camera located in the middle of the device records images at a rate of 25 frames per second.
2015-06-15
Technical Paper
2015-01-2130
Melissa Bravin, J. Walter Strapp, Jeanne Mason
Abstract In the last several years, the aviation industry has improved its understanding of jet engine events related to the ingestion of ice crystal particles. Ice crystal icing has caused powerloss and compressor damage events (henceforth referred to as “engine events”) during flights of large transport aircraft, commuter aircraft and business jets. A database has been created at Boeing to aid in analysis and study of these engine events. This paper will examine trends in the engine event database to better understand the weather which is associated with events. The event database will be evaluated for a number of criteria, such as the global location of the event, at what time of day the event occurred, in what season the event occurred, and whether there were local meteorological influences at play. A large proportion of the engine events occur in tropical convection over the ocean.
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
2015-01-2107
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.
2015-06-15
Technical Paper
2015-01-2105
Darren Glenn Jackson
Aircraft icing has been a focus of the aviation industry for many years. While regulations existed for the certification of aircraft and engine ice protection systems (IPS), no FAA or EASA regulations pertaining to certification of ice detection systems existed for much of this time. Interim policy on ice detection systems has been issued through the form of AC 20-73A as well as FAA Issue Papers and EASA Certification Review Items to deal mainly with Primary Ice Detection Systems. A few years ago, the FAA released an update to 14 CFR 25.1419 through Amendment 25-129 which provided the framework for the usage of ice detection systems on aircraft. As a result of the ATR-72 crash in Roselawn, Indiana due to Supercooled Large Droplets (SLD) along with the Air France Flight 447 accident and numerous engine flame-outs due to ice crystals, both the FAA and EASA have developed new regulations to address these concerns.
2015-06-15
Journal Article
2015-01-2106
Mark Ray, Kaare Anderson
Abstract Cloud phase discrimination, coupled with measurements of liquid water content (LWC) and ice water content (IWC) as well as the detection and discrimination of supercooled large droplets (SLD), are of primary importance in aviation safety due to several high-profile incidents over the past two decades. The UTC Aerospace Systems Optical Ice Detector (OID) is a prototype laser sensor intended to discriminate cloud phase, to quantify LWC and IWC, and to detect SLD and differentiate SLD conditions from those of Appendix C. Phase discrimination is achieved through depolarization scattering measurements of a circularly polarized laser beam transmitted into the cloud. Optical extinction measurements indicate the liquid and ice water contents, while the differential backscatter from two distinct probe laser wavelengths implies an effective droplet size.
2015-06-15
Journal Article
2015-01-2154
Franck Hervy, Severine Maguis, François Virion, Biagio Esposito, Hugo Pervier
Abstract The A06 test facility designed for combustor testing in altitude has been modified to be converted in an icing facility for probe testing. The objective was to be able to simulate ice crystals conditions at high altitude, high Mach number and low temperature. This facility has been upgraded in several steps extending the median size of the ice crystals produced and the ice water content range. The aero-thermal and icing capabilities have been assessed during commissioning tests. Finally, in order to prepare the calibration of the facility, some measurement techniques for cloud characterization have been selected or developed, especially for cloud uniformity measurement.
2015-06-15
Journal Article
2015-01-2155
Tadas P. Bartkus, Peter Struk, Jen-Ching Tsao
Abstract This paper describes a numerical model that simulates the thermal interaction between ice particles, water droplets, and the flowing air applicable during icing wind tunnel tests where there is significant phase-change of the cloud. It has been previously observed that test conditions, most notably temperature and humidity, change when the icing cloud is activated. It is hypothesized that the ice particles and water droplets thermally interact with the flowing air causing the air temperature and humidity to change by the time it reaches the test section. Unlike previous models where the air and particles are uncoupled, this model attempts to explain the observed changes in test conditions by coupling the conservation of mass and energy equations. The model is compared to measurements taken during wind tunnel tests simulating ice-crystal and mixed-phase icing that relate to ice accretions within turbofan engines.
Viewing 91 to 120 of 23660

Filter