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Viewing 61 to 90 of 16177
2015-06-15
Technical Paper
2015-01-2163
Caio Fuzaro Rafael, Diogo Mendes Pio, Guilherme A. Lima da Silva
Abstract The present paper presents a validation of momentum boundary-layer integral solution and finite-volume Reynolds-Averaged Navier Stokes (RANS) Computational Fluid Dynamics (CFD) results for skin friction around airfoils NACA 8H12 and MMB-V2 as well as heat transfer around an isothermal cylinder with rough surface. The objective is to propose a two-equation integral model and compare its predictions to results from a robust CFD tool, to experimental data and to results from a one-equation integral solution. The latter is the mathematical model used by classic 2D icing codes. All proposed model predictions are compared to CFD results for verification and, whenever possible, to experimental data for validation. The code-to-code verification brings reliability to both the proposed code and the CFD tool when there is no test data available.
2015-06-15
Technical Paper
2015-01-2095
Wolfgang Hassler, Reinhard F.A. Puffing, Andreas Tramposch
Abstract This paper deals with thermal ice protection of electrically heated restraining grids designed for applications in the environmental control system (ECS) of passenger aircraft. The restraining grids described in the paper consist of strung, electrically insulated wire and are - in certain operation modes of the ECS - exposed to an airstream containing supercooled water droplets and/or ice particles. Heat is generated in the wire by an electric current, and the temperature of the wire is controlled with the aid of an electronic control system. A substantial question for laying out the controller and for operating the grids is the following: What minimum heating power is required to prevent ice accretion on the surface of the wire, i.e., what is the least heating power that is necessary to keep a grid being exposed to specific icing conditions devoid of ice? This problem is studied for a simple model system first and is then examined for restraining grids.
2015-06-15
Technical Paper
2015-01-2098
Stephen T. McClain, Mario Vargas, Richard E. Kreeger, Jenching Tsao
Abstract Many studies have been performed to quantify the formation and evolution of roughness on ice shapes created in Appendix C icing conditions, which exhibits supercooled liquid droplets ranging from 1-50 µm. For example Anderson and Shin (1997), Anderson et al. (1998), and Shin (1994) represent early studies of ice roughness during short-duration icing events measured in the Icing Research Tunnel at the NASA Glenn Research Center. In the historical literature, image analysis techniques were employed to characterize the roughness. Using multiple images of the roughness elements, these studies of roughness focused on extracting parametric representations of ice roughness elements. While the image analysis approach enabled many insights into icing physics, recent improvements in laser scanning approaches have revolutionized the process of ice accretion shape characterization.
2015-06-15
Technical Paper
2015-01-2097
Timothy A. Shannon, Stephen T. McClain
Abstract Changes in convection coefficient caused by the changes in surface roughness characteristics along an iced NACA 0012 airfoil were investigated in the 61-cm by 61-cm (24 in. by 24 in.) Baylor Subsonic Wind Tunnel using a 91.4-cm (36-in.) long heated aerodynamic test plate and infrared thermometry. A foam insert was constructed and installed on the wind tunnel ceiling to create flow acceleration along the test plate replicating the scaled flow acceleration the along the leading 17.1% (3.6 in.) of a 53.3-cm (21-in.) NACA 0012 airfoil. Two sets of rough surface panels were constructed for the study, and each surface used the same basic random droplet pattern created using the Lagrangian droplet simulator of Tecson and McClain (2013). For the first surface, the roughness pattern was replicated with the same geometry over the plate following a smooth-to-rough transition location noted in historical literature for the case being replicated.
2015-06-15
Technical Paper
2015-01-2099
Mario Vargas, Charles Ruggeri, Peter Struk, Mike Pereira, Duane Revilock, Richard Kreeger
This work presents the results of an experimental study of ice particle impacts on a flat plate made of glass. The experiment was conducted at the Ballistics Impact Laboratory of NASA Glenn Research Center in 2014 and is part of the NASA fundamental research efforts to study physics of ice particles impact on a surface, in order to improve understanding of ice crystal ingestion and ice accretion inside jet engines. The ice particles, which were nominally spherical ranging in initial diameter between 1 and 3.5 millimeters, were accelerated to velocities from 20 to 130 m/s using a pressure gun. High speed cameras captured the pre-impact particle diameter and velocity data as well as the post-impact fragment data. The initial stages of ice particle breakup were captured and studied at 1,000,000 frames per second with a high speed camera imaging at a plane normal to the impact surface.
2015-06-15
Technical Paper
2015-01-2100
Yongsheng Lian, Yisen Guo
Abstract In this paper we numerically investigated the impact of large droplets on smooth solid surfaces to understand the splashing mechanism involved in ice accretion due to supercooled large droplets. A Navier-Stokes solver was used to describe the flow field, the moment-of-fluid (MOF) method was used to capture the droplet interface evolution, and the adaptive mesh refinement technique was employed to refine the mesh near the region of interest. We investigated the effect of air on splashing mechanism and confirmed that a low pressure can suppress the droplet splashing. The size distribution of splashed secondary droplets was studied and showed good agreement with experimental results. The effect of surface curvature on the splashing phenomenon was highlighted. Finally, the droplet impact on a NACA 23012 airfoil was studied and the water collection efficiency was investigated.
2015-06-15
Technical Paper
2015-01-2101
Hai Li, Ilia Roisman, Cameron Tropea
Abstract Airframe icing caused by supercooled large droplets (SLD) has been identified as a severe hazard in aviation. This study presents an investigation of impact of a supercooled drop onto superhydrophobic and partially wettable substrates. Drop impact, spreading and rebound were observed using a high-speed video system. The maximum spreading diameter of an impacting drop on partially wettable surfaces was measured. The temperature effect on this parameter was only minor for a wide range of the drop and substrate temperatures. However solidification hindered receding when both the drop and substrate temperatures were below 0°C. The minimum receding diameter and the speed of ice accretion on the substrate were measured for various wall and drop temperatures. The two parameters increased almost linearly with the decrease of the wall temperature, but eventually leveled off beyond a certain substrate temperature.
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
Technical Paper
2015-01-2103
Christian Bartels, Julien Cliquet, Carlos Bautista
Abstract In order to comply with applicable certification regulations, airframers have to demonstrate safe operation of their aircraft in icing conditions. Part of this demonstration is often a numerical prediction of the potential ice accretion on unprotected surfaces. The software ONICE2D, originally developed at the Office National d'Études et de Recherche Aérospatial (ONERA), is used at Airbus for predicting ice accretions on wing-like geometries. The original version of the software uses a flow solution of the 2D full-potential equation on a structured C-grid as basis for an ice accretion prediction. Because of known limitations of this approach, an interface was added between ONICE2D and TAU [6], a hybrid flow solver for the Navier-Stokes equations. The paper first details the approach selected to implement the interface to the hybrid flow solver TAU.
2015-06-15
Technical Paper
2015-01-2096
Philippe Reulet, Bertrand Aupoix, David Donjat, Francis Micheli
Abstract Numerical simulation of ice accretion on aircraft surfaces necessitates a good prediction of wall friction coefficient and wall heat transfer coefficient. After the icing process begins, surface roughness induces a high increase of friction and heat transfer, but simple Reynolds analogy is no longer valid. An experimental campaign is conducted to provide a database for numerical model development in the simple configuration of a heated flat plate under turbulent cold airflow conditions. The flat plate model is placed in the centre of the test section of a wind tunnel. The test model is designed according to constraints for the identification of friction and heat transfer coefficients. It includes three identical resin plates which are moulded to obtain a specified roughness on the upper surface exposed to the flow. Only the 3rd resin plate is heated on its lower face by an electrical heater connected to a temperature regulator.
2015-06-15
Technical Paper
2015-01-2152
Earle Williams, Michael F. Donovan, David J. Smalley, Robert G. Hallowell, Elaine P. Griffin, Kenta T. Hood, Betty J. Bennett, Mengistu Wolde, Alexei V. Korolev
MIT Lincoln Laboratory is tasked by the U.S. Federal Aviation Administration to investigate the use of the NEXRAD polarimetric radars for the remote sensing of icing conditions hazardous to aircraft. A critical aspect of the investigation concerns validation that has relied upon commercial airline icing pilot reports and a dedicated campaign of in situ flights in winter storms. During the month of February in 2012 and 2013, the CONVAIR 580 aircraft operated by the National Research Council of Canada was used for in situ validation of snowstorm characteristics under simultaneous observation by NEXRAD radars in Cleveland, Ohio and Buffalo, New York. The most anisotropic and easily distinguished winter targets to dual pol radar are ice crystals.
2015-06-15
Technical Paper
2015-01-2122
Cameron Butler, Eric Loth
Abstract In recent years, there has been a growing desire to incorporate computational methods into aircraft icing certification practices. To improve understanding of ice shapes, a new experimental program in the NASA Icing Research Tunnel (IRT) will investigate swept hybrid models which are very large relative to the test section and are intended to operate at high lift coefficients. The present computations were conducted to help plan the experiments and to ascertain any effects of flow separation and unsteady forces. As they can be useful in robustly and accurately predicting large separation regions and capturing flow unsteadiness, a Detached Eddy Simulation (DES) approach has been adopted for simulating the flow over these large high-lift wing sections. The DES methodology was first validated using experimental data from an unswept NACA 0012 airfoil with leading-edge ice accretion, showing reasonable performance.
2015-06-15
Technical Paper
2015-01-2127
Andrea Munzing, Franck Hervy, Stephane Catris
Abstract A helicopter blade profile was tested in the DGA Aero-engine Testing's icing altitude test facility S1 in Saclay, France during the winter of 2013/2014. The airfoil was a helicopter main rotor OA312 blade profile made out of composite material and with a metallic erosion shield. Dry air and ice accretion tests have been performed in order to assess the iced airfoil's aerodynamic behaviour. Several icing conditions were tested up through Mach numbers around 0.6. This paper presents the test setup, the test model and some of the test results. The test results presented in this paper include the ice shapes generated as well as dry air and iced airfoil lift and drag curves (polars) which were obtained with the real ice shapes on the airfoil.
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
2015-01-2128
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
2015-01-2123
Eric Defer, Jean-Louis Brenguier, Jos De Laat, Julien Delanoe, Fabien Dezitter, Michael Faivre, Amanda Gounou, Alice Grandin, Anthony Guignard, Jan Fokke Meirink, Jean-Marc Moisselin, Frederic Parol, Alain Protat, Claudine Vanbauce
Abstract The High Altitude Ice Crystals (HAIC) Sub-Project 3 (SP3) focuses on the detection of cloud regions with high ice water content (IWC) from current available remote sensing observations of space-based geostationary and low-orbit missions. The SP3 activities are aimed at supporting operationally the two up-coming HAIC flight campaigns (the first one in May 2015 in Cayenne, French Guyana; the second one in January 2016 in Darwin, Australia) and ultimately provide near real-time cloud monitoring to Air Traffic Management. More in detail the SP3 activities focus on the detection of high IWC from space-borne geostationary Meteosat daytime imagery, explore the synergy of concurrent multi-spectral multiple-technique observations from the low-orbit A-Train mission to identify specific signatures in high IWC cloud regions, and finally develop a satellite-based nowcasting tool to track and monitor convective systems over the Tropical Atlantic.
2015-05-20
WIP Standard
AIR6510
This SAE Aerospace Information Report (AIR) comprises the technical terms and nomenclature, together with their definitions and abbreviations that are used in Aircraft Fuel Systems.
2015-05-20
WIP Standard
AS4130C
Scope is unavailable.
2015-05-20
WIP Standard
AS4136C
Scope is unavailable.
2015-05-20
WIP Standard
J1855
This SAE Recommended Practice describes the method for safe deployment of air bag modules in vehicles equipped with electrically actuated air bag systems for the purpose of disposal. It is intended to provide a procedure which does not require significant technical expertise, is easy to operate, and is readily available, to be used by automobile dismantlers or vehicle shredders to deploy air bag modules prior to automobile reclamation.
2015-05-20
WIP Standard
AS4134C
Scope is unavailable.
2015-05-20
Book
This is the electronic format of the Journal.
2015-05-19
WIP Standard
ARP6063
This SAE Aerospace Recommended Practice (ARP) provides guidance for the verification and certification of a “commercial” fixed wing aircraft fuel tank inerting system (FTIS) and will provide technical references and data regarding ground and flight testing of an FTIS. The intent of this ARP is to address issues associated with the verification requirements based on current regulatory guidance per AC25.981-2C
2015-05-19
WIP Standard
J2944_201505
This Recommended Practice, Operational Definitions of Driving Performance Measures and Statistics, provides functional definitions of and guidance for performance measures and statistics concerned with driving on roadways. As a consequence, measurements and statistics will be calculated and reported in a consistent manner in SAE and ISO standards, journal articles proceedings papers, technical reports, and presentations so that the procedures and results can be more readily compared. Only measures and statistics pertaining to driver/vehicle responses that affect the lateral and longitudinal positioning of a road vehicle are currently provided in this document. Measures and statistics covering other aspects of driving performance may be included in future editions. For eye glance-related measures and statistics, see SAE J2396 (Society of Automotive Engineers, 2007) and ISO 15007-1 (International Standards Organization, 2002).
2015-05-15
Article
A tire pressure monitoring chipset can help fleet managers improve fuel economy and tell when vehicles are overloaded while also simplifying setup times. The Freescale Semiconductor device is said to be the industry’s smallest sensor, yet it has a broad operating range of 100-1500 kPa, exceeding the levels normally required for heavy commercial trucks.
2015-05-13
WIP Standard
ARP6339
This ARP provides recommended practice on the considerations and methodology to demonstrate acceptable performance of the Engine components / fuel system, and APU, whilst operating throughout the flight cycle / engine duty for continuous operation with iced fuel and short duration operation with a snowshower resulting from release of accreted ice from fuel washed surfaces, where no anti-icing additives are present (e.g. Fuel System Icing Inhibitor FSII or alternative). Two scenarios must be considered when demonstrating the capability of Engine components / fuel system, and APU to operate with fuel borne ice to satisfy certification regulations applications in support of FAA Part 23 and Part 25, CFR Part 33, and corresponding EASA CS-E regulations, and equivalent Military application requirements.
2015-05-08
WIP Standard
J2365
This SAE Recommended Practice applies to both Original Equipment Manufacturer (OEM) and aftermarket route-guidance and navigation system functions for passenger vehicles. This recommended practice provides a method for calculating the time required to complete navigation system-related tasks. These estimates may be used as an aid to assess the safety and usability of alternative navigation and route guidance system interfaces to assist in their design. This document does not consider voice-activated controls, voice output from the navigation system, communication between the driver and others, or passenger operation.
2015-05-07
Standard
J2876_201505
This procedure establishes a recommended practice for performing a Low Speed Knee Slider test to the Hybrid III 50th Male Anthropomorphic Test Device (ATD or crash dummy). This test was created to satisfy the demand from industry to have a certification test which produces similar results to an actual low energy automotive impact test. An inherent problem exists with the current certification procedure because the normal (2.75 m/s) knee slider test has test corridors that do not represent typical displacements seen in these low energy impact tests. The normal test corridors specify a force requirement at 10 mm and at 18 mm, while the low speed test needs to have a peak displacement around 10 mm.
2015-05-07
Standard
J2980_201505
This SAE Recommended Practice presents a method and example results for determining the Automotive Safety Integrity Level (ASIL) for automotive electrical and electronic (E/E) systems. This activity is required by ISO 26262-3:2011 [1], and it is intended that the process and results herein are consistent with ISO 26262:2011 [1]. The technical focus of this document is on vehicle motion control systems. It is limited to passenger cars weighing up to 3.5 metric tons. Furthermore, the scope of this recommended practice is limited to collision-related hazards. ISO 26262:2011 [1] has a wider scope than SAE J2980, covering other functions and accidents (not just motion control or collisions as in SAE J2980).
2015-05-05
WIP Standard
J3099
Presents the seating accommodation model used to determine seat track length for accommodation in design.
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