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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
2015-01-2132
David L. Rigby, Joseph Veres, Colin Bidwell
Abstract Three-dimensional simulations of the Honeywell ALF502 low pressure compressor (sometimes called a booster) using the NASA Glenn code GlennHT have been carried out. A total of eight operating points were investigated. These operating points are at, or near, points where engine icing has been determined to be likely. The results of this study were used, in a companion paper, for further analysis such as predicting collection efficiency of ice particles and ice growth rates at various locations in the compressor. In an effort to minimize computational effort, inviscid solutions with slip walls are produced. A mixing plane boundary condition is used between each blade row, resulting in convergence to steady state within each blade row. Comparisons of the results are made to other simplified analysis. An additional modification to the simulation process is also presented.
2015-06-15
Technical Paper
2015-01-2131
Colin Bidwell, David Rigby
Abstract A flow and ice particle trajectory analysis was performed for the booster of the Honeywell ALF502 engine. The analysis focused on two closely related conditions one of which produced an icing event and another which did not during testing of the ALF502 engine in the Propulsion Systems Lab (PSL) at NASA Glenn Research Center. The flow analysis was generated using the NASA Glenn GlennHT flow solver and the particle analysis was generated using the NASA Glenn LEWICE3D v3.63 ice accretion software. The inflow conditions for the two conditions were similar with the main differences being that the condition that produced the icing event was 6.8 K colder than the non-icing event case and the inflow ice water content (IWC) for the non-icing event case was 50% less than for the icing event case.
2015-06-15
Technical Paper
2015-01-2137
Daniel R. Adriaansen, Paul Prestopnik, George McCabe, Marcia Politovich
Abstract Advancements in numerical weather prediction (NWP) models continue to enhance the quality of in-flight icing forecasts and diagnoses. When diagnosing current in-flight icing conditions, observational datasets are combined with NWP model output to form a more accurate representation of those conditions. Surface observations are heavily relied upon 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 model grid. An alternate solution to the current method for incorporating these point-based observations into the in-flight icing diagnoses was developed. The basis for the new method is rooted in a concept borrowed from signal and image processing known as dithering.
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
2015-01-2135
Martin Schulz, Michael Sinapius
Abstract 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 a design value. Several methods have been published to measure the adhesive strength of ice. This paper analyzes the interface stresses created by those methods and discusses the way the adhesion strength is derived. A finite element method tool is used to provide insight into the stress state 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 local stress concentrations and crack nucleation. Hence, the derived adhesion strength may not be comparable within different testing methods, because each testing procedure neglects different parameters like specimen size, substrate thickness and stiffness.
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
2015-01-2124
Amanda Gounou, Jean-Marc Moisselin, Frédéric Autones, Dominique Levaillant, Jean-Louis Brenguier, Eric Défer, Michael Faivre, Alice Grandin, Fabien Dezitter, Sandra Turner
Abstract Glaciated icing conditions potentially leading to in-service event are often encountered in the vicinity of deep convective clouds. Nowcasting of these conditions with space-borne observations would be of a great help for improving flight safety and air-traffic management but still remains challenging. In the framework of the HAIC (High Altitude Ice Crystals) project, methods to detect and track regions of high ice water content from space-based geostationary and low orbit mission are investigated. A first HAIC/HIWC field campaign has been carried out in Australia in January-March 2014 to sample meteorological conditions potentially leading to glaciated icing conditions. During the campaign, several nowcasting tools were successfully operated such as the Rapid Development Thunderstorm (RDT) product that detects the convective areas from infrared geostationary imagery.
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.
2015-06-15
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
2015-01-2129
Andrea Munzing, Stephane Catris
Abstract Different Airbus Helicopters main rotor blade profiles were tested in different icing wind tunnels and for different icing conditions. One of the objectives of the accretion tests was to validate the use of 2D icing scaling laws established for fixed wing aircraft on helicopter blade profiles. Therefore, ice shapes resulting from tests with the same icing similarity parameters are compared to each other allowing the assessment of icing scaling laws for helicopter applications. This paper presents the icing scaling laws used at Airbus Helicopters on blade profiles, the different test set ups and test models and it presents the comparison of the ice shapes collected during the icing wind tunnel test campaigns.
2015-06-15
Technical Paper
2015-01-2121
Yong Chen, Liang Fu
Abstract In helicopter, the icing rotor blades will decrease the effectiveness of the helicopter and endanger the lives of the pilots. The asymmetrical ice break-up and shedding could also lead to severe vibrations of the rotor blade. Ice break-up from the main rotor may strike the fuselage and tail rotor, even worse, find its way into the engine, which may cause serious aircraft accidents. An understanding of the mechanisms responsible for ice shedding process is necessary in order to optimize the helicopter rotor blade design and de-icing system to avoid hazardous ice shedding. In this paper, the ice shedding model is improved by introducing a bilinear cohesive zone model (CZM) to simulate the initiation and propagation of ice/blade interface crack. A maximum stress criterion is used to describe the failure occurred in the ice.
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
2015-01-2151
Reinhard F.A. Puffing, Wolfgang Hassler, Andreas Tramposch, Marian Peciar
Abstract When studying ice accretion processes experimentally it is desirable to document the generated ice shapes as accurately as possible. The obtained set of data can then be used for aerodynamic studies, the improvement of icing test facilities, the development of design criteria, the validation of ice accretion simulation tools as well as other applications. In the past, various ice shape documentation methods have been established including photography, cross-sectional tracing, molding and casting as well as 3D-scanning. This work introduces a new ice shape documentation technique based on active 3D-scanning in combination with fluorescent dyes and an optimized set of optical filters. The new approach allows recording the time-resolved three dimensional growth of an arbitrary ice shape. Based on this concept a so-called 4D-scanning system is developed, which allows a detailed evaluation of icing experiments and hence a better understanding of the ice accretion process itself.
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
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
Technical Paper
2015-01-2148
Erdem Ayan, Serkan Ozgen, Canibek Murat, Erhan Tarhan
Abstract Ice crystal ingestion to aircraft engines may cause ice to accrete on internal components, leading to flameout, mechanical damage, rollback, etc. Many in-flight incidents have occurred in the last decades due to engine failures especially at high altitude convective weather conditions [1]. Thus, in the framework of HAIC FP7 European project, the physical mechanisms of ice accretion on surfaces exposed to ice-crystals and mixed-phase conditions are investigated. Within the HAIC FP7 European project, TAI will implement models related to the ice crystal accretion calculation to the existing ice accumulation prediction program for droplets, namely TAICE. Considered models include heat transfer & phase change model, drag model and impact model. Moreover, trajectory model and Extended Messinger Model require some modifications to be used for ice crystal accretion predictions.
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.
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
Abstract 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
2015-01-2153
David Serke, Michael King, Andrew Reehorst
In early 2015, a field campaign was conducted at the NASA Glenn Research Center in Cleveland, Ohio, USA. The purpose of the campaign is to test several prototype algorithms meant to detect the location and severity of in-flight icing (or icing aloft, as opposed to ground icing) within the terminal airspace. Terminal airspace for this project is currently defined as within 25 kilometers horizontal distance of the terminal, which in this instance is Hopkins International Airport in Cleveland. Two new and improved algorithms that utilize ground-based remote sensing instrumentation have been developed and were operated during the field campaign. The first is the ‘NASA Icing Remote Sensing System’, or NIRSS. The second algorithm is the ‘Radar Icing Algorithm’, or RadIA.
2015-06-15
Technical Paper
2015-01-2140
Emiliano Iuliano
Abstract The presence of ice crystals in deep convective clouds has become a major threat for aviation safety. As recently highlighted, once inside the engine core, ice crystals encounter a high temperature environment, so that they can either melt by convection with the warm environment or melt upon impact onto hot static components of the low-pressure components. As a consequence, a liquid film may form which, in turn, is able to capture further ice crystals by sticking mechanism. This scenario results in a significant decrease of the local surface temperature and, hence, promotes the accretion of ice. Therefore, it is clear that icing simulation capabilities have to be updated in order to be able to predict such phenomena. The paper proposes an extension of CIRA icing tools to deal with ice crystals along with supercooled water droplets.
2015-06-15
Technical Paper
2015-01-2141
Markus Widhalm
Abstract This paper focuses on the numerical simulation of the motion of regular shaped ice particles under the forces and torques generated by aerodynamic loading. Ice particles can occur during landing and take-off of aircraft at ground level up to the stratosphere at cruising altitude. It may be expected that the particle Reynolds number is high because the flow around the aircraft is in certain regions characterized by strong acceleration and deceleration of the flow. In combination with this flow pattern, the rotation of particles becomes important. Applicable translational and rotational equations of motion combined with a drag correlation taking into account rotation will be derived for a Lagrangian type particle tracking. Orientation is described with quaternions to prevent the singularities associated with the description by Euler angles. The influence of regular shaped particles on collection efficiencies is investigated.
2015-06-15
Technical Paper
2015-01-2138
E. Iuliano, E. Montreuil, E. Norde, E.T.A. Van der Weide, H.W.M. Hoeijmakers
Abstract In this study a comparison is made between results from three Eulerian-based computational methods that predict the ice crystal trajectories and impingement on a NACA-0012 airfoil. The computational methods are being developed within CIRA (Imp2D/3D), ONERA (CEDRE/Spiree) and University of Twente (MooseMBIce). Eulerian models describing ice crystal transport are complex because physical phenomena, like drag force, heat transfer and phase change, depend on the particle's sphericity. Few correlations exist for the drag of non-spherical particles and heat transfer of these particles. The effect or non-spherical particles on the collection efficiency will be shown on a 2D airfoil.
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
2015-01-2139
E.J. Grift, E. Norde, E.T.A. Van der Weide, H.W.M. Hoeijmakers
Abstract In this study the characteristics of ice crystals on their trajectory in a single stage of a turbofan engine compressor are determined. The particle trajectories are calculated with a Lagrangian method employing a classical fourth-order Runge-Kutta time integration scheme. The air flow field is provided as input and is a steady flow field solution governed by the Euler equations. The single compressor stage is represented using a cascaded grid. The grid consists of three parts of which the first and the last part are stator parts and the centre part is a rotor. Each particle is modelled as a non-rotating rigid sphere. The remaining model does allow the exchange of heat and mass to and from the particle resulting in a mass, temperature and phase change of the particle. The phase change is based on a perfectly concentric ice core-water film model and it is assumed that the particle is at uniform temperature.
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
2015-01-2160
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
2015-01-2161
Kazem Hasanzadeh, Dorian Pena, Yannick Hoarau, Eric Laurendeau
Abstract The paper presents the framework of fully automated two/three dimensional ice accretion simulation package, with emphasis on the remeshing step. The NSMB3D-ICE Navier-Stokes code, coupled to an Eulerian droplet module and iterative Messinger thermodynamic model, can perform multi time-steps ice accretion simulations via an automated multi-block elliptic/parabolic grid generation code (NSGRID3D). Attention is paid to the efficiency and robustness of the numerical calculations especially for complex 3D glaze ice simulation. The new automated multi time-step icing code NSMB3D-ICE/NSGRID3D is used to compute several icing studies on the GLC305 wing for rime and glaze ice cases.
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