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Viewing 1 to 30 of 1874
2015-06-15
Technical Paper
2015-01-2097
Timothy A. Shannon, Stephen T. McClain
As ice begins to accrete on an aircraft in flight, the stochastic nature of the droplet impingement process dictates that the accreted ice is uneven along the surface resulting in roughness. Because of the varying convection along the surface and local shear rates along the surface, the resulting roughness statistical characteristics on an unswept wing are not constant along the streamwise direction. However, historical studies of roughness on iced airfoils performed in the NASA Icing Research Tunnel (IRT) at NASA Glenn Research Center employed image analysis approaches to create parametric representations of ice roughness element development over time. Because of the parametric descriptions and the limitations of the surface characterizations, ice roughness is often treated in analytical approaches and computational models as having constant parametric properties over the entire ice accretion area.
2015-06-15
Technical Paper
2015-01-2102
Guilin Lei, Wei Dong, Jianjun Zhu, Mei Zheng
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.
2015-06-15
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
2015-01-2096
The correct prediction of ice accretion on aircraft surfaces by simulation necessitates a good prediction of friction coefficient and heat transfer coefficient. After icing process, surface roughness induces high increase of friction and heat transfer, but simple Reynolds analogy is no longer valid. An experimental campaign is conducted in order to provide a database for numerical model development in the simple configuration of a flat plate under turbulent airflow conditions. The flat plate model is placed in the centre of the test section of a windtunnel with an improved temperature regulation. 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. The latest resin plate is heated on its lower face by an electrical heater connected to a temperature regulator.
2015-06-15
Technical Paper
2015-01-2120
Yong Han Yeong, Eric Loth, Jack Sokhey, Alexis Lambourne
Superhydrophobic coatings have shown promise in reducing ice adhesion on a surface. However, recent superhydrophobic ice adhesion studies were conducted at either ice accretion conditions that do not resemble aerospace icing conditions, or at low super-cooled droplet impact speeds (less than 10 m/s). Therefore, a detailed experiment was conducted to measure the ice adhesion strength of various superhydrophobic coatings in an icing wind tunnel at an air speed of 50 m/s and at a temperature of -15°C with a super-cooled icing cloud consisting of 20 µm droplets. The ice was accreted on 3 mm thick, 30 mm diameter discs and then removed by pressurized nitrogen through the access hole in a tensile direction for a measurement of the ice fracture energy. Results showed no relationship between coating wettability parameters (water contact and receding angles) with ice fracture energy but depicted a general increase in fracture energy with increasing surface auto-correlation lengths.
2015-06-15
Technical Paper
2015-01-2159
Philipp Grimmer, Swarupini Ganesan, Michael Haupt, Jakob Barz, Christian Oehr, Thomas Hirth
The formation of ice on surfaces of technical devices or transportation vehicles can lead to several problems, like reduced functionality, reduced energy efficiency or operational safety. 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 from nature, a “super-hydrophobic” surface can be produced by the combination of micro-structures and a hydrophobic surface coating. By a hot stamping process we have generated differently shaped microstructures (cylinders, ellipses and lines) on polyurethane films which are afterwards coated by a PECVD process with thin, hydrophobic fluorocarbon or silicone-like films. PU films are suitable for outdoor use, because they are resistant against erosion and UV radiation.
2015-06-15
Technical Paper
2015-01-2160
Alidad Amirfazli
Coatings that shed drops can help with icing mitigation. Shedding of a drop depends on surface wettability. To characterize the shedding of a drop, in an aerodynamic context, the minimum air velocity to displace the drop is measured, i.e., the critical air velocity. Recently, superhydrophobic surfaces (SHS) with their ability to shed drops have gained much attention to combat icing. However, questions remain about their performance when exposed to UV, or water for long periods. In this study of its first kind, the effect prolonged UV and water exposure on shedding of drops from 6 different SHS (four commercially available coatings (C1 to C4), and two developed in-house, S1 and S2) was investigated in an icing wind tunnel. Critical air velocity, and contact angle values show that UV-treatment has a stronger adverse effect for S1 and C1 surfaces, compared to other coatings. Water treatment adversely affects S1, C1 and C2 samples more than other samples.
2015-06-15
Technical Paper
2015-01-2149
Caroline Laforte, Caroline Blackburn, Jean Perron
Ideally, an icephobic coating applied to ice-exposed surfaces appears to be an interesting solution to prevent ice build-up. Over the last decade, developments of efficient icephobic coatings were multiplied. Some materials that reduce ice adhesion have been developed from which the ice can be more easily shed, possibly even with existing forces such as wind, gravity and vibrations. This paper will depict icephobic coating performances of 262 different coatings and 11 grease type substrates tested over the past 10 years at the Anti-Icing Materials International Laboratory (AMIL). Since 2003, the icephobic performance is evaluated with two main test methods. A first test method was developed in regards to measuring the ice adhesion and its reduction. A second test was then developed to measure the ice accumulation reduction.
2015-06-15
Technical Paper
2015-01-2157
Mengyao Leng, Shinan Chang, Yuanyuan Zhao
Aircraft icing causes a great threaten to flight safety. With the development of anti/de-icing systems for aeronautics, some attention is paid on coating strategies for reducing the total amount of water present on the surface. By application of hydrophobic or super-hydrophobic coatings, characterized by low surface wettability, 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. In order to contain the effect of surface wettability, it is necessary to obtain an accurate model for calculating dynamic contact angle (DCA). Instead of average static contact angle or empirical equation, the formula used in this work is derived theoretically, as a function of the capillary number, advancing and receding contact angle, and the roughness of the solid surface.
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
Recently coatings have been considered as promising preventive measures for in-cloud icing which may occur at the leading edge area of the lifting surface of aircraft in cold climate. In terms of the wettability, coating reveals hydrophobicity or hydrophilicity depending on its property. At the same time it has high or low values on the ice adhesion strength. It is then required that users should find out which of anti-icing or de-icing coating can apply to in order to make full use of the distinguished characteristics. For all that, coating cannot prevent ice accretion by itself unfortunately, which means that no perfect icephobic coatings have been developed up to the present. Thus, coatings apply to the surfaces with devices such as an electric heating system or a load-applying machine such that they can function with less energy and more effectiveness.
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
2015-01-2078
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
2015-01-2076
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
2015-01-2092
David M. Orchard, Catherine Clark, Myron Oleskiw
As a result of a series of international collaborative projects to measure and assess aircraft icing environments that contain Supercooled Large Droplets (SLDs), it has been demonstrated that the current icing envelopes, e.g., Code of Federal Regulations (CFR) 14 Part 25 Appendix C, do not adequately capture conditions where SLDs are present. Consequently, regulatory authorities are considering extensions to the certification requirements to include SLD environments. In order to demonstrate compliance to an updated icing certification that includes SLD conditions, airframe and aircraft component manufactures will have an increased need for access to test facilities that can simulate this environment. To address this need, a series of tests have been conducted within the NRC’s Altitude Icing Wind Tunnel (AIWT) to examine the feasibility of expanding its current capabilities to include the SLD icing envelope.
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.
2015-04-16
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.
2015-04-08
WIP Standard
AIR1168/4B
This section presents the basic equations for computing ice protection requirements for nontransparent and transparent surfaces and for fog and frost protection of windshields. Simplified graphical presentations suitable for preliminary design and a description of various types of ice, fog, frost, and rain protection systems are also presented.
2015-04-03
WIP Standard
ARP1915E
This SAE Aerospace Recommended Practice (ARP) outlines the basic general design considerations for transport aircraft tow bars. It does not cover the requirements for tow bars intended for aircraft with a maximum ramp mass (MRW) below 8600 kg (19 000 lb).
2015-04-03
WIP Standard
AS1614D
This SAE Aerospace Standard (AS) specifies the interface requirements for tow bar attachment fittings on the nose gear (when towing operations are performed from the nose gear) of conventional tricycle type landing gears of commercial civil transport aircraft with a maximum ramp weight higher than 50 000 kg (110 000 lb), commonly designated as "main line aircraft". Its purpose is to achieve tow bar attachment fittings interface standardization by aircraft weight category (which determines tow bar forces) in order to ensure that one single type of tow bar with a standard connection can be used for all aircraft types within or near that weight category, so as to assist operators and airport handling companies in reducing the number of different tow bar types used.
2015-03-11
WIP Standard
ARP5533A
This SAE Aerospace Recommended Practice (ARP) covers the requirements for a Stationary Runway Weather Information System (referred to as the systemRWIS or System) to monitor the surface conditions of airfield operational areas to ensure saferthe conditions of the aircraft ground operations of aircraft areas of an airport. The RWIS shall providesystem provides (1) temperature and condition information of runway, taxiway, and ramp pavements and (2) provide atmospheric weather information conditions that assist needed airport personnel to maintain safer and more for efficient airport operations and maintenance. The system can be either a wired system or a wireless system.
2015-03-03
WIP Standard
AS1988B
Pallet extensions provide support for items of cargo beyond either the short or the long sides of a pallet, allowing increased volume to be achieved. The extensions are desgtned to suit the contour of wide-bodied aircraft. Each extension consists of a panel or shelf extending upwards and outboards within an envelope bounded by the ULD contour (see Figures 1, 2, 3, and 4). The panel or shelf is secured in this position by means of chains, cables, or structural members attached to the rails of the adjacent sides of the pallent edge.
2015-02-24
WIP Standard
AMS6890
No change
2015-02-09
WIP Standard
ARD6888
The purpose of this document is to specify the functional requirements for a miniature connector to be used for health monitoring purposes on aircrafts (including harsh environment such as the powerplant). It is actually a family of miniature connectors that is specified in this document for various uses (e.g. pin counts) and environments. This specification will be used by the SAE connector committee to work on a dedicated connector standard.
2015-01-22
Standard
AIR6284
This SAE Aerospace Information Report (AIR) covers forced air technology including: reference material, equipment, safety, operation, and methodology. This resource document is intended to provide information and minimum safety guidelines regarding use of forced air or forced air/fluid equipment to remove frozen contaminants. During the effective period of this document, relevant sections herein should be considered and included in all/any relevant SAE documents.
2014-12-12
Standard
AS755F
This SAE Aerospace Standard (AS) provides a performance station designation system for aircraft propulsion systems and their derivatives. The station numbering conventions presented herein are for use in all communications concerning propulsion system performance such as computer programs, data reduction, design activities, and published documents. They are intended to facilitate calculations by the program user without unduly restricting the method of calculation used by the program supplier. The contents of this document were previously a subset of AS755E. Due to the growing complexity of station numbering schemes and an industry desire to expand nomenclature descriptions, a decision was made to separate the “station numbering” and “nomenclature” contents of AS755 into two separate documents. AS755 will continue to maintain standards for station numbering. SAE Aerospace Standard AS6502 will maintain standards for classical nomenclature moving forward.
2014-12-05
WIP Standard
AIR1869D
This SAE Aerospace Information Report (AIR) covers information relative to ULDs (Unit Load Devices) container and pallet configurations, maximum usable container, pallet and bulk compartment volumes and tare weights for the lower deck of various wide-body aircraft. Bulk compartment volumes are also included for standard-body aircraft. This document brings together data concerning the lower deck capacity of wide-body and standard- body airplanes. The information includes airplanes manufactured by Airbus, Boeing, British Aerospace, British Aircraft, Fokker-VFW, Hawker Siddeley, Ilyushin, Lockheed and McDonnell- Douglas.
2014-12-01
Standard
AIR4243A
This document discusses the work done by the U.S. Army Corps of Engineers and the Waterways Experiment Station (WES) in support of SAE A-5 Committee activity on Aerospace Landing Gear Systems. It is an example of how seemingly unrelated disciplines can be combined effectively for the eventual benefit of the overall aircraft systems, where that system includes the total airfield environment in which the aircraft must operate. In summary, this AIR documents the history of aircraft flotation analysis as it involves WES and the SAE.
2014-11-05
WIP Standard
ARP6887
The ARP shall cover the objectives and activities of Verification & Vallidation Processes required to assure high quality and/or criticality level of an IVHM Systems and Software.
2014-10-06
Standard
ARP1558
This SAE Aerospace Recommended Practice (ARP) discusses damage to aircraft fuselages caused by ground equipment contact at servicing and recommends methods to be incorporated or considered in ground equipment design for protection against that damage.
2014-09-30
Standard
AIR1673B
Manufacturers/designers of all aircraft equipped with a pallet/container capability have provided a means of linking the ground loaders/elevators with the aircraft sill for the smoother transfer of pallets and containers into or out of the aircraft holds. Use of the aircraft attachment points may be used as a means of averting damage to the aircraft door frames and other important parts. Latch-on guarantees fore and aft and vertical alignment of the loader bed with the aircraft doorway, when used in conjunction with the appropriate ground equipment. This SAE Aerospace Information Report (AIR) has been prepared by SAE Subcommittee AGE-2A to present a review of the current range of aircraft attachment points on wide body aircraft and those narrow body aircraft with a ULD cargo capability. Airline operators, who utilized these facilities, have been faced with a growing number of adaptor bars necessary to suit each type of aircraft and door position.
Viewing 1 to 30 of 1874

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