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Viewing 1 to 30 of 7471
2015-06-15
Technical Paper
2015-01-2135
Martin Schulz, Michael Sinapius
A designer of a new mechanical ice protection system for airplanes needs to know how much and in which way he has to deform the surface to break off the ice. The ice adhesion strength is often used as design value. To measure the adhesive strength several methods have been published. This paper presents a review about those methods and discusses the way the adhesion strength is derived. Finite Element Method is used to give a good insight into the stress state at failure for different load cases. The implication of these illustrations is that equations which use only ultimate force and total interfacial area to calculate adhesion strength miss the local stress state at the crack tip and the complex process of crack growing. Hence the derived adhesion strength may not be comparable with others, because they depend in fact on neglected parameters like specimen size, substrate thickness and stiffness.
2015-06-15
Technical Paper
2015-01-2137
Daniel R. Adriaansen, Paul Prestopnik, George McCabe, Marcia Politovich
Advancements in numerical weather prediction (NWP) modeling continue to enhance the quality of in-flight icing forecasts and diagnoses. When performing a diagnosis of current in-flight icing conditions, observational datasets can be combined with NWP model output to form a more accurate representation. These diagnoses are traditionally tied to a three-dimensional grid, typically the grid of the NWP model data chosen for use. Surface observations are heavily relied upon when performing in-flight icing diagnoses to identify cloud coverage and cloud base height above observing stations. One of the major challenges of using these point-based or otherwise limited observations of cloud properties is extending the influence of the observation to nearby points on the grid. For example, we seek an improved solution to the problem of combining point-based METARs observations with NWP model grids over the current method.
2015-06-15
Technical Paper
2015-01-2076
Caroline Laforte, Neal Wesley, Marc Mario Tremblay
Abstract This study presents a new method to evaluate and compare the anti-icing performance, i.e., the ability to delay the reformation of ice, of runways and taxiways deicing/anti-icing fluids (RDF) under icing precipitation, based on the skid resistance values, obtained with the Portable Skid Resistance Tester (PSRT). In summary, the test consists of applying, on a standardized concrete pavement sample, a given quantity of de-icing fluid. Following this application, the concrete sample is submitted to low freezing drizzle intensities, in a cold chamber at −5.0 ± 0.3°C. The skid resistance of concrete is measured at 5 minute intervals, until the concrete becomes completely iced. The anti-icing performance of 5 different fluids, both experimental and commercial, was assessed in comparison with a reference solution of 50% w/w K-formate. The anti-icing performance is analyzed based on two parameters: the duration (Icing Protection Time, IPT) and the effectiveness of this protection.
2015-06-15
Technical Paper
2015-01-2078
Alric Rothmayer, Hui Hu
Abstract A strong air/water interaction theory is used to develop a fast simplified model for the trapping of water in a film that flows over sub-grid surface roughness. The sub-grid model is used to compute correction factors that can alter mass transport within the film. The sub-grid model is integrated into a covariant film mass transport model of film flow past three-dimensional surfaces in a form that is suitable for use in aircraft icing codes. Sample calculations are presented to illustrate the application of the model.
2015-06-15
Technical Paper
2015-01-2093
Maxime Henno
Abstract Advanced sizing of the thermal wing ice protection system (WIPS) requires an improved and a robust manner to simulate the system operation in unsteady phases and particularly in de-icing operations. A two dimensional numerical tool has been developed to enable the simulation of unsteady anti-icing and de-icing operations. For example, the WIPS may be activated with delay after entering into the icing conditions. In this case, ice starts to accrete on the leading edge before the WIPS heats up the skin. Another example is the ground activation of the WIPS for several seconds to check its functionality: low external cooling may cause high thermal constraints that must be estimated with accuracy to avoid adverse effects on the structure. Thermal de-icing WIPS integrated in composite structures intrinsically have unsteady behaviors; the tool enables the computation of the skin temperature evolution with the time.
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.
2015-06-15
Technical Paper
2015-01-2120
Yong Han Yeong, Eric Loth, Jack Sokhey, Alexis Lambourne
Researchers have recently focused on superhydrophobic coatings as an ice-mitigation tool. These surfaces have a high degree of water-repellency and were shown in previous low-speed droplet studies to reduce surface ice adhesion strength. However, there is little research regarding testing in aerospace icing conditions, i.e. high-speed super-cooled droplet impact (> 50 m/s) on a freezing substrate and air temperature. A detailed set of experiments were conducted in an icing wind tunnel to measure the ice adhesion strength of various superhydrophobic coatings by subjecting the surfaces to a super-cooled icing cloud consisting of 20 μm droplets and at a constant LWC of 0.4 g/m3. Test conditions include air speeds of 50 m/s and 70 m/s and in glaze (−5°C) and rime ice regimes (−15°C). The accreted ice was then removed by pressurized nitrogen in a mode 1 (tensile) adhesion test.
2015-06-15
Technical Paper
2015-01-2149
Caroline Laforte, Caroline Blackburn, Jean Perron
Abstract This paper depicts icephobic coating performances of 274 different coatings, including 11 grease-type coatings, which were tested over the past 10 years in various research projects at the Anti-Icing Materials International Laboratory (AMIL). Icephobic performance is evaluated using two comparative test methods. The first method, the ice Centrifuge Adhesion Test (CAT), measures the force required to separate the accreted ice from the coating (e.g. adhesive failure). The test involves simultaneously icing, under supercooled precipitation, the extremity of bare reference and freshly coated aluminum samples. The ice adhesion shear stress is calculated from the ice detachment rotation speed. The results are reported as Adhesion Reduction Factor (ARF), which is the ice adhesion stress on the bare aluminum reference samples divided by the ice adhesion stress on the coated samples.
2015-06-15
Technical Paper
2015-01-2157
Mengyao Leng, Shinan Chang, Yuanyuan Zhao
Abstract Aircraft icing causes a great threaten to flight safety. With the development of anti-icing or de-icing systems for aircraft, some attention has been paid on coating strategies for an efficient way to prevent water remaining on the surface. By application of hydrophobic or super-hydrophobic coatings, characterized by low surface adhesion, shedding of liquid from the surface can be enhanced. The motivation behind this work is to identify the way that wettability affects the motion of runback water, and establish an empirical formula of critical departure diameter. The surface property is characterized by the equilibrium contact angle and the hysteresis angle. The relationship between the air speed and the droplet shedding diameter is studied, corresponding to different surfaces.
2015-06-15
Technical Paper
2015-01-2159
Philipp Grimmer, Swarupini Ganesan, Michael Haupt, Jakob Barz, Christian Oehr, Thomas Hirth
Abstract As known de-icing methods use a high amount of energy or environmentally harmful chemicals, research has focused lately on passive de-icing by functional surfaces with an improved removal of ice (de-icing) or a reduced formation of it (anti-icing). Inspired by the Lotus plant leaf, a “superhydrophobic” surface can be produced by the combination of a hierarchical micro/nanoscale roughness and a hydrophobic surface coating. By a hot stamping process we have generated differently shaped microstructures (cylinders, ellipses) on polyurethane (PU) films which were afterwards coated by a plasma enhanced chemical vapor deposition (PECVD) process with thin, hydrophobic fluorocarbon films. This combination of methods could be a process for the production of large area functionalized films. PU films are suitable for outdoor use, because they are resistant against erosion and UV radiation. The films can be glued to different geometries and can easily be exchanged if damaged.
2015-06-15
Technical Paper
2015-01-2158
Tatsuma Hyugaji, Shigeo Kimura, Haruka Endo, Mitsugu Hasegawa, Hirotaka Sakaue, Katsuaki Morita, Yoichi Yamagishi, Nadine Rehfeld, Benoit Berton, Francesc Diaz, Tarou Tanaka
Coating has been recently considered as having good potential for use in preventing in-cloud icing on the leading edge of the lifting surfaces of an aircraft in cold climates. In terms of wettability, a coat may exhibit hydrophobicity or hydrophilicity depending on its specific properties. The same applies to the ice adhesion strength, which may be either high or low. It is thus necessary to determine which type of anti-icing or de-icing coat would be appropriate for a particular application in order to fully utilize its specific properties. Notwithstanding, a coat is incapable of preventing ice accretion by itself, and a perfect icephobic coat is yet to be developed. Coating is also sometimes applied to the surfaces of electrical heaters and load-applying machines to enable them to function more effectively and use less energy. The coating used for an electric heater, for instance, should be hydrophobic because of the need for rapid removal of molten water from the surface.
2015-06-15
Technical Paper
2015-01-2160
Alidad Amirfazli
Abstract The surfaces that shed drops helps with mitigation of icing. Shedding of drop depends on surface hydrophobicity, which becomes affected when exposed to water and/or UV. The hydrophobicity degradation of six (Spray SHS, Etched Al SHS, Hydrobead, Neverwet, Waterbeader, and WX2100) different super-hydrophobic surfaces (SHS), exposed to water or UV, were studied from the drop shedding perspective. Two methods were adopted for the hydrophobicity analysis. Among them, one is to study the contact angles (CA) and contact angle hysteresis (CAH) change at static state (i.e., no airflow) compared to the untreated surface. The other one is to analyze the change in critical air velocity (Uc) for a given drop exposed to airflow, on water/UV treated surfaces at room temperature (22 °C) and icing conditions (−1 and −7 °C).
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
2015-01-2102
Guilin Lei, Wei Dong, Jianjun Zhu, Mei Zheng
Abstract The numerical simulation of ice melting process on an iced helicopter rotor blade is presented. The ice melting model uses an enthalpy-porosity formulation, and treats the liquid-solid mushy zone as a porous zone with porosity equal to the liquid fraction. The ice shape on the blade section is obtained by the icing code with a dynamic mesh module. Both of the temperature change and the ice-melting process on the rotor blade section surface are analyzed. The phenomenon of ice melting is analyzed through the change of temperature and liquid fraction on the abrasion/ice interface. The liquid fraction change as with time on the abrasion/ice surface is observed, which describes the ice-melting process well. The numerical results show that the ice melting process can be simulated effectively by the melting model. The de-icing process can be monitored by observing the change of the liquid fraction of the area around the abrasion/ice interface.
2015-05-20
Book
This is the electronic format of the Journal.
2015-05-07
WIP Standard
ARP1202B
This Aerospace Recommenced Practice (ARP) defines a series of ball bearings which are specifically designed to support the rotor in a dynamic balancing machine. By establishing certain bearing sizes the number of required balancing machine support adapters will be reduced. The intent is that each size bearing identified by its outside diameter and width will be capable of accommodating any bore diameter within the specified range of that size. This ARP specifies both the nominal dimensions and the tolerances for a series of ball bearings with semifinished inside diameters which are suitable for supporting gas turbine rotating components in dynamic balancing machines.
2015-05-07
WIP Standard
ARP1340B
This document specifies those requirements and procedures for periodic tests to insure maintenance of balance machine capabilities for balancing jet engine components.
2015-05-07
Standard
J2842_201505
The intent of this standard is to establish a framework to assure that all evaporators for R-744, R-1234yf, and R-445A mobile air conditioning (MAC) systems meet appropriate testing and labeling requirements. SAE J639 requires vehicle manufacturers to perform assessments to minimize reasonable risks in production MAC systems. The evaporator (as designed and manufactured) shall be part of that risk assessment and it is the responsibility of the vehicle manufacturer to assure all relevant aspects of the evaporator are included. It is the responsibility of all vehicle or evaporator manufacturers to comply with the standards of this document at a minimum. (Substitution of specific test procedures by vehicle manufactures that correlate well to field return data is acceptable.) As appropriate, this standard can be used as a guide to support risk assessments.
2015-05-06
WIP Standard
AMS1385B
This specification covers a solvent-based compound in the form of a liquid. This compound has been used typically for removal of carbonaceous soils and paint from aircraft turbine engine parts by immersion in liquid at elevated temperature, but usage is not limited to such applications. This compound should not be used on steel parts having hardness of 40 HRC or over.
2015-05-06
WIP Standard
AS6324
This document establishes process parameters for gas turbine rotor balancing. Adherence to the recommendations made herein will facilitate attainment of the usually high degree of accuracy and precision required for jet engine rotor balance.
2015-05-06
WIP Standard
AMS2631E
This specification covers the procedure for ultrasonic inspection of wrought titanium and titanium alloy products 0.25 inch (6.4 mm) and over in cross-section (thickness) or diameter.
2015-05-01
WIP Standard
AIR4827B
This SAE Aerospace Information Report (AIR) has been written for individuals associated with ground level testing of turbofan and turbojet engines and particularly for those who might be interested in investigating the performance characteristics of a new test cell design or of proposed modifications to an existing test cell by means of a scale model test.
2015-04-28
WIP Standard
AIR6892
This SAE Aerospace Information Report (AIR) is applicable to rotorcraft structural health monitoring (SHM) applications, both commercial and military, where end users are seeking guidance on the definition, development, integration, qualification, and certification of SHM technologies to achieve enhanced safety and reduced maintenance burden based on the lessons learned from existing Health and Usage Monitoring Systems (HUMS). While guidance on SHM business case analysis would be useful to the community, such guidance is beyond the scope of this AIR. For the purpose of this document, SHM is defined as “the process of acquiring and analyzing data from on-board sensors to evaluate the health of a structure.” The suite of on-board sensors could include any presently installed aircraft sensors as well as new sensors to be defined in the future. Interrogation of the sensors could be done onboard during flight or using ground support equipment.
2015-04-19
WIP Standard
J1115
Historically SAE has been concerned with nomenclature as an integral part of the standards development process. Guidelines for automotive nomenclature were written in 1916, were last revised in 1941, and were included in the SAE Handbook until 1962. The present diversity of groups working on nomenclature in the various ground vehicle committees led to the organization of the Nomenclature Advisory Committee under SAE Automotive Council.
2015-04-19
WIP Standard
J2740
This Technical Information Report defines the General Motors UART Serial Data Communications Bus, commonly referred to as GM UART. This document should be used in conjunction with SAE J2534-2 in order to fully implement GM UART in an SAE J2534 interface. SAE J2534-1 includes requirements for an interface that can be used to program certain emission-related Electronic Control Units (ECU) as required by U.S. regulations, and SAE J2534-2 defines enhanced functionality required to program additional ECUs not mandated by current U.S. regulations. The purpose of this document is to specify the requirements necessary to implement GM UART in an aftermarket SAE J2534 interface intended for use by independent automotive service facilities to program GM UART ECUs in General Motors vehicles.
2015-04-16
Book
Robert J. Flemming
The effects of inflight atmospheric icing can be devastating to aircraft. Universities and industry have been hard at work to respond to the challenge of maintaining flight safety in all weather conditions. Proposed changes in the regulations for operation in icing conditions are sure to keep this type of research and development at its highest level. This is especially true for the effects of ice crystals in the atmosphere, and for the threat associated with supercooled large drop (SLD) icing. This collection of ten SAE International technical papers brings together vital contributions to the subject. Icing on aircraft surfaces would not be a problem if a material were discovered that prevented the freezing and accretion of supercooled drops. Many options that appeared to have promising icephobic properties have had serious shortfalls in durability.
2015-04-15
Book
“Spotlight on Design: Insight” features an in-depth look at the latest technology breakthroughs impacting mobility. Viewers are virtually taken to labs and research centers to learn how design engineers are enhancing product performance/reliability, reducing cost, improving quality, safety or environmental impact, and achieving regulatory compliance. Telematics, the convergence of telecommunications and informatics, uses electronic and computer technology built in to the vehicle to provide vehicle tracking, satellite navigation, wireless technology, and diagnostic information. In the episode “Diagnostics and Prognostics: Telematics Deep Dive” (8:09), an engineer from Delphi’s Telematics program discusses the advantages and challenges of telematics devices for the automotive industry, demonstrates the installation of an aftermarket telematics device, and shows how telematics can enhance diagnostics and preventative maintenance.
2015-04-15
WIP Standard
ARP4990B
This SAE Aerospace Recommended Practice (ARP) provides to the aerospace industry a procedure for the consistent and accurate calculation of fuel flow using turbine flowmeters during development, production, and post overhaul/repair gas turbine engine testing.
2015-04-15
Book
“Spotlight on Design” features video interviews and case study segments, focusing on the latest technology breakthroughs. Viewers are virtually taken to labs and research centers to learn how design engineers are enhancing product performance/reliability, reducing cost, improving quality, safety or environmental impact, and achieving regulatory compliance. In the episode “Diagnostics and Prognostics: Proactive Maintenance and Failure Prevention” (21:04), Delphi engineers explain how they leverage the growing number of sensors and computing power in vehicles to diagnose and proactively solve emerging mechanical or electronic problems, before a breakdown occurs. This video also looks at the next generation of automotive telematics, with HEM Data demonstrating how in-vehicle data acquisition is used to monitor the inner workings of vehicles.
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