Browse Topic: Icing and ice detection

Items (300)
Find
Design Solutions for Ice-Induced CNG Filling Failures: Field Issue Resolution through Filter Geometry and Seal Material Reengineering2026-26-0515To be published on 01/16/2026
Compressed Natural Gas (CNG) systems in automotive applications are highly sensitive to fuel quality, especially with respect to moisture content. Field issues were observed where high moisture levels in the CNG led to the formation of ice inside the receptacle during refueling operations. This ice formation obstructed the CNG filling process and adversely impacted the sealing performance of the O-ring, particularly under low-temperature conditions induced by pressure differentials between the storage tank and the filling station. Investigation revealed that the existing tablet-type filter design contributed to moisture entrapment within its wire mesh, exacerbating ice formation within the receptacle. To address this, the filter design was modified from a tablet-type to a cup-type filter, significantly reducing the likelihood of moisture retention and subsequent ice formation. Additionally, the O-ring material was upgraded to a formulation with improved sealing properties at lower
Virmani, Nishant, Sawant, Shivraj Madhukar, C R, ABHIJITH
Wetting prediction of power train components under the influence moving components using smooth particle hydrodynamics2026-26-0384To be published on 01/16/2026
Passenger cars are subjected to extensive conditions ranging from driving through wet roads, water puddles, icy roads, and rain. This can affect the performance of different parts over time, one such aspect is the vehicle corrosion, whose impact is felt on a wide spectrum from aesthetics to safety due to loss of material. The general condition for corrosion mainly requires electrolyte to be present on the metal surface, which is transported through self-soiling and foreign soiling. Vehicle soiling is an important aspect for vehicle design. Amongst the many aspects of vehicle soiling, one important aspect is the prediction of water accumulation that enables prediction of corrosion sensitive regions in the vehicle. Power train components like Engine, transmission and corresponding wiring harness are at highest risk of water-wetting, As the vehicle drives through the water pool the components are not just wet by the direct inflow of water but also by water being splashed by moving
Shukrey, Sarthak, Pattankar, Rohan, Yenugu, Srinivasa
Water Spray and High Humidity Endurance Test Methods for AMS1424 and AMS1428 Aircraft Deicing/Anti-Icing FluidsAS5901E (Current)11/26/2025
This document establishes the minimum requirements for an environmental test chamber, and test procedures to carry out anti-icing performance tests according to the current materials specification for aircraft deicing/anti-icing fluids. The primary purpose for such a test method is to determine the anti icing endurance under controlled laboratory conditions of AMS1424 Type I and AMS1428 Type II, III, and IV fluids.
G-12ADF Aircraft Deicing Fluids
Leaf-Inspired Surface Prevents Frost FormationTBMG-3685805/01/2020
Researchers have discovered a new way to significantly reduce frost formation on any surface. The finding could help decrease the amount of energy needed for defrosting and could potentially result in fewer canceled flights, which can be grounded by even the slightest layer of frost.
Unsettled Topics in Unmanned Aerial Vehicle IcingEPR202000804/27/2020
Unmanned aerial vehicles (UAVs) are an emerging technology with a large variety of commercial and military applications. In-flight icing occurs during flight in supercooled clouds or freezing precipitation and is a potential hazard to all aircraft. In-flight icing on UAVs imposes a major limitation on the operational envelope. This report describes the unsettled topics related to UAV icing. First, typical UAV applications and the general hazards of icing are described. Second, an overview of the special technical characteristics of icing on autonomous and unmanned aircraft is given. Third, the operational challenges for flight in icing conditions are discussed. Fourth, technologies for ice protection that mitigate the icing hazard are introduced. Fifth, the tools and methods required to understand UAV icing and to develop aircraft with cold-weather capabilities are presented. Finally, an assessment of the current and future regulations regarding icing on UAVs is provided.Icing is a key
Hann, Richard, Johansen, Tor A.
Prevention of Snow Accretion on Camera Lenses of Autonomous Vehicles2020-01-010504/14/2020
With the rapid development of artificial intelligence, the autonomous vehicles (AV) have attracted considerable attention in the automotive industry. However, different factors negatively impact the adoption of the AVs, delaying their successful commercialization. Accretion of atmospheric icing, especially wet snow, on AV sensors causes blockage on their lenses, making them prone to lose their sight, in turn, increasing potential chances of accidents. In this study, two different designs are proposed in order to prevent snow accretion on the lenses of AVs via air flow across the lens surface. In both designs, lenses made of plain glass and superhydrophobic coated glass surfaces are tested. While some researchers have shown promise of water repellency on superhydrophobic surfaces, more snow accretion is observed on the superhydrophobic surfaces, when compared to the plain glass lenses. In the experiments, snow is formed using a novel snow gun inside a walk-in cold room connected to a
Mohammadian, Behrouz, Sarayloo, Mehdi, Heil, Jamie, Sojoudi, Hossein, Robertson, Michael, Hong, Haiping, Tran, Tommy, Patil, Sunil, Krishnan, Venkatesh
Application of Extended Messinger Models to Complex Geometries2020-01-002203/10/2020
Since, ice accretion can significantly degrade the performance and the stability of an airborne vehicle, it is imperative to be able to model it accurately. While ice accretion studies have been performed on airplane wings and helicopter blades in abundance, there are few that attempt to model the process on more complex geometries such as fuselages. This paper proposes a methodology that extends an existing in-house Extended Messinger solver to complex geometries by introducing the capability to work with unstructured grids and carry out spatial surface streamwise marching. For the work presented here commercial solvers such as STAR-CCM+ and ANSYS Fluent are used for the flow field and droplet dispersed phase computations. The ice accretion is carried out using an in-house icing solver called GT-ICE. The predictions by GT-ICE are compared to available experimental data, or to predictions by other solvers such as LEWICE and STAR-CCM+. Three different cases with varying levels of
Gupta, Avani, Sankar, Lakshmi, Kreeger, Richard
Sensor Uses Microwaves to Determine Real-Time Ice AccumulationTBMG-3619503/01/2020
A sensor detects the precise moment when ice begins to form on a surface. Due to their high sensitivity, low power, ease of fabrication, and planar profile, microwave resonators were chosen for the device.
EquipmentAS6286/2A (Current)11/08/2019
This document covers the standards of de-icing/anti-icing equipment. In conjunction with the main document and other related slash sheets it will provide guidelines for the proper procedures to deice and anti-ice aircraft on the ground information to support this training program is provided to make the material a better tool for the preparation and execution of the training & qualification. It is intended to provide a common basis for de-icing/anti-icing training and qualification for de- icing providers and airlines. This material was compiled using various international documents with support from SAE documents and individually contributed editorial comments. Its purpose is to serve as a "Globalized Deicing Training Manual".
G-12T Training and Quality Programs Committee
Compensating the Effects of Ice Crystal Icing on the Engine Performance by Control Methods2019-01-186209/16/2019
Aircraft equipment is operated in a wide range of external conditions, which, with a certain combination of environmental parameters, can lead to icing of the engine internal elements. Due to icing, the engine components performance characteristics change what leads to decrease in thrust, gas dynamic stability, durability, etc. Safe aircraft operation and its desired performance may be lost as a result of such external influence. Therefore, it is relevant to study the possibilities of reducing the icing effect with the help of a special engine control. The focus of this paper is to determine control methods of an aircraft gas turbine engine addressing this problem. The object of the study is a modern commercial turbofan with a bypass ratio of about 9. In this paper analysis of the effect of ice crystal icing on the engine components performance is conducted. To perform simulation of the engine performance under such impact, degraded components characteristics was introduced into
Gurevich, Oskar, Smetanin, Sergei, Trifonov, Mikhail
Phase-Switching Liquids as Anti-Icing MaterialsTBMG-3475507/01/2019
Techniques to prevent frost and ice formation on surfaces rely heavily on heating or on liquid chemicals that need to be repeatedly reapplied because they easily wash away. Even advanced anti-icing materials have problems functioning under conditions of high humidity and subzero conditions.
Aerodynamic Assessment of Complex 3D Ice Shape Replications2019-01-193606/10/2019
This work introduces an approach allowing the detailed replication of ice shapes generated in icing wind tunnels, with a special focus on complex and strongly varying ice structures, e.g., ice feathers or residual ice stemming from incomplete removal of accreted ice by ice protection systems. 3D-scans are used as an input for the manufacturing process of the ice shape replica. The manufacturing approach itself is based on additive techniques using semi-flexible materials. In contrast to existing replication techniques, this approach allows also clean areas between ice-covered surface locations. In the present paper, a quality assessment based on the comparison of the lift coefficients of real and corresponding artificial ice shapes is presented.
Puffing, Reinhard, Hassler, Wolfgang, Neubauer, Thomas, Kozomara, David, Ferschitz, Hermann
Additional Comparison of Iced Aerodynamic Measurements on a Swept Wing from Two Wind Tunnels2019-01-198606/10/2019
Artificial ice shapes of various geometric fidelity were tested on a wing model based on the Common Research Model. Low Reynolds number tests were conducted at Wichita State University’s Walter H. Beech Memorial Wind Tunnel utilizing an 8.9% scale model, and high Reynolds number tests were conducted at ONERA’s F1 wind tunnel utilizing a 13.3% scale model. Several identical geometrically-scaled ice shapes were tested at both facilities, and the results were compared at overlapping Reynolds and Mach numbers. This was to ensure that the results and trends observed at low Reynolds number could be applied and continued to high, near-flight Reynolds number. The data from Wichita State University and ONERA F1 agreed well at matched Reynolds and Mach numbers. The lift and pitching moment curves agreed very well for most configurations. This confirmed results from previous tests with other ice shapes that indicated the data from the low Reynolds number tests could be used to understand iced
Lee, Sam, Broeren, Andy, Woodard, Brian, Lum, Christopher, Smith, Timothy
Experimental Aerodynamic Simulation of a Scallop Ice Accretion on a Swept Wing2019-01-198406/10/2019
Understanding the aerodynamic impact of swept-wing ice accretions is a crucial component of the design of modern aircraft. Computer-simulation tools are commonly used to approximate ice shapes, so the necessary level of detail or fidelity of those simulated ice shapes must be understood relative to high-fidelity representations of the ice. Previous tests were performed in the NASA Icing Research Tunnel to acquire high-fidelity ice shapes. From this database, full-span artificial ice shapes were designed and manufactured for both an 8.9%-scale and 13.3%-scale semispan wing model of the CRM65 which has been established as the full-scale baseline for this swept-wing project. These models were tested in the Walter H. Beech wind tunnel at Wichita State University and at the ONERA F1 facility, respectively. The data collected in the Wichita St. University wind tunnel provided a low-Reynolds number baseline study while the pressurized F1 facility produced data over a wide range of Reynolds
Woodard, Brian, Broeren, Andy, Potapczuk, Mark, Lee, Sam, Lum, Christopher, Bragg, Michael, Smith, Timothy
CH148 Icing Flight Test Performance Data Correlation2019-01-199106/10/2019
This paper presents results of correlation of an empirical code to CH148 Cyclone® icing flight test performance data. Predicted icing main rotor torque penalties, generated using the Sikorsky Generalized Rotor Performance (GRP) model with the integral DELICE icing performance module, are compared to flight test results. DELICE methodology adjustments are shown that lead to CH148 test data correlation and improved correlation to previously-examined S-92A™ icing flight test performance data. Finally, a comparison of results between GRP and Sikorsky-Maryland FreeWake is shown, providing an indication of the influence of rotor wake methodology on icing model correlation.
Griffiths, Daniel
Semi-Empirical Modelling of Erosion Phenomena for Ice Crystal Icing Numerical Simulation2019-01-196706/10/2019
The aim of this work is to develop a semi-empirical model for erosion phenomena under ice crystal condition, which is one of the major phenomena for ice crystal accretion. Such a model would be able to calculate the erosion rate caused by impinging ice crystals on accreted ice layer. This model is based on Finnie [1] and Bitter [2] [3] solid/solid collision theory which assumes that metal erosion due to sand impingement is driven by two phenomena: cutting wear and deformation wear. These two phenomena are strongly dependent on the particle density, velocity and shape, as well as on the surface physical properties such as Young modulus, Poisson ratio, surface yield strength and hardness. Moreover, cutting wear is mostly driven by tangential velocity and is more effective for ductile eroded body, whereas deformation wear is driven by normal velocity and is more effective for brittle eroded body. Several researchers based their erosion modelling on these two phenomena such as Hutchings et
Charton, Virgile, Trontin, Pierre, Aouizerate, Gilles, Villedieu, Philippe
MUSIC-haic: 3D Multidisciplinary Tools for the Simulation of In-Flight Icing due to High Altitude Ice Crystals2019-01-196206/10/2019
Icing is a major hazard for aviation safety. Over the last decades an additional risk has been identified when flying in clouds with high concentrations of ice-crystals where ice accretion may occur on warm parts of the engine core, resulting in engine incidents such as loss of engine thrust, strong vibrations, blade damage, or even the inability to restart engines. Performing physical engine tests in icing wind tunnels is extremely challenging, therefore, the need for numerical simulation tools able to accurately predict ICI (Ice Crystal Icing) is urgent and paramount for the aeronautics industry, especially regarding the development of new generation engines (UHBR = Ultra High Bypass Ratio, CROR = Counter rotating Open Rotor, ATP = Advanced Turboprop) for which analysis methods largely based on previous engines experience may be less and less applicable. The European research project MUSIC-haic has been conceived to fill this gap and has started in September 2018. MUSIC-haic brings
Villedieu, Philippe, Trontin, Pierre, Aouizerate, Gilles, Bansmer, Stephan, Vanacore, Paolo, Roisman, Ilia, Tropea, Cameron
Flight in Icing Regulatory Evolution and the Influence on Aircraft Design2019-01-195806/10/2019
Flight in icing for transport category aircraft certification presents a particularly challenging set of considerations to establish adequate safety commensurate with the associated risk while balancing design complexity and efficiency. A review highlighting important aspects of the regulatory evolution and guiding principles for flight in icing certification is presented, including the current standards and recent rulemaking activity. While historical icing certification relied on a simple yet subjective requirement to demonstrate that an aircraft is capable of operating safely within the prescribed icing envelopes, the certification requirements associated with demonstrating an adequate level of safety have progressively evolved into more explicit quantitative performance and qualitative handling qualities standards now scattered throughout the Federal Aviation Administration (FAA) Title 14 Code of Federal Regulations (CFRs) Part 25 Subpart B Flight standards which are largely
Leopold, David
Numerical and Experimental Investigation of Ice Adhesion Using the Blister Test2019-01-194806/10/2019
Structures in cold weather environments are susceptible to atmospheric ice formation. A fracture mechanics based approach is proposed for in situ characterization of the interfacial fracture energy of ice on different substrates. This paper summarizes the development of the experimental and analytical framework to measure the ice adhesion energy, calibrated on static ice. The testing configuration utilizes a shaft-loaded blister test to produce stable crack propagation, from a well-defined pre-crack at the interface of the ice layer and the substrate. Measurements of the fracture energy are taken over a range of ice thicknesses and surface roughnesses. The developed analytical framework to estimate adhesion energy are verified and calibrated via finite element numerical simulation of the proposed geometric configuration and employing cohesive surfaces along the interface to simulate the crack nucleation and propagation process. Several different phenomena were observed include the
Giuffre, Christopher, Dawood, Bishoy, Yavas, Denizhan, Bastawros, Ashraf
Aero-Engine Inlet Vane Structure Optimization for Anti-Icing with Hot Air Film Using Neural Network and Genetic Algorithm2019-01-202106/10/2019
An improved anti-icing design with film heating ejection slot and cover for the inlet part of aero-engine was brought out, which combines the interior jet impingement with the exterior hot air film heating and shows promising application for those parts manufactured with composite materials. A hybrid method based on the combination of the Back Propagation Neural Network (BPNN) and Genetic Algorithm (GA) is developed to optimize the anti-icing design for a typical aero-engine inlet vane in two dimensions. The optimization aims to maximize the heating performance of the hot air film, which is assessed by the heating effectiveness. The film-heating ejection angle and the cover opening angle are the two geometric variables to be optimized. Numerical model was established and validated to generate training and testing samples for BPNN, which was used to predict the objective function and find the optimal design variables in conjunction with the GA. The optimal values of the film-heating
Liu, Jie, Ke, Peng
Numerical Optimisation of a Helicopter Engine Inlet Electrothermal Ice Protection System2019-01-204206/10/2019
This paper details the process involved in the numerical optimisation of a helicopter engine inlet electrothermal ice protection system. Although the process was developed using a production aircraft, it is demonstrated here using a generic intake and flight conditions, due to confidentiality of the actual design. The process includes adherence to the overall system design objectives (maximum power demand), including tolerances required to account for an industrial system (aircraft voltage variation, manufacturing tolerances). The numerical optimisation was performed using a combination of 2D and 3D methods to define the required heated area, power density, locations and settings for temperature control sensors. The use of 2D design tools allows a rapid iteration process to be performed, leading to the possibility of a higher level of optimisation within the allowable time-frame compared to the use of full 3D methods. Different flight settings (different Angle of Attack and Angle of
Moser, Richard, Roberts, Ian
Aerodynamic Comparison of Freezing Rain and Freezing Drizzle Conditions at the RTA Icing Wind Tunnel2019-01-202306/10/2019
The simulation of icing conditions in icing wind tunnels (IWTs) is a significant element in the certification of aircraft components and offers unique possibilities for research purposes. Up to 2014 only the conditions defined in Appendix C of the EASA Certification Specification 25, respectively the FAA Code of Federal Regulations Title 14 Part 25 were used for the certification processes in IWTs. In addition, Appendix O was introduced in 2014 to cover the supercooled large droplet (SLD) icing conditions of freezing drizzle and freezing rain, which pose a potential risk for flight safety. The simulation of SLD icing in IWTs is, due to the different behavior of the large droplets, very challenging and not all required conditions have successfully been recreated yet. RTA Rail Tec Arsenal Fahrzeugversuchsanlage GmbH has focused on the simulation of in-flight icing conditions since 2012 and increased effort was put in the simulation of SLDs in recent years. During several research
Breitfuß, Wolfgang, Wannemacher, Michael, Knöbl, Florian, Ferschitz, Hermann
A Continuing Investigation of Diurnal and Location Trends in an Ice Crystal Icing Engine Event Database2019-01-196406/10/2019
Due to ongoing efforts by the aviation industry, much has been learned over the last several years regarding jet engine power loss and compressor damage events caused by the ingestion of high concentrations of ice crystal particles into the core flow path. Boeing has created and maintained a database of such ice crystal icing (ICI) events to aid in analysis and further study of this phenomenon. This article provides a general update on statistics derived from the Boeing event database, and provides more details on specific event clusters of interest. A series of three flight campaigns have, over the past five years, collected in-situ data in deep convective clouds that will be used for the assessment of the new FAA CFR Part 33 ice crystal environmental envelope Appendix D, and the equivalent EASA CS-25 Appendix P. The most recent Boeing engine event study in 2015 focused on oceanic cloud systems that caused events in Southeast Asia, a region expected to have similar cloud properties as
Bravin, Melissa, Strapp, J. Walter
Uncertainty of the Ice Particles Median Mass Diameters Retrieved from the HAIC-HIWC Dataset: A Study of the Influence of the Mass Retrieval Method2019-01-198306/10/2019
In response to the ice crystal icing hazard identified twenty years ago, aviation industry, regulation authorities, and research centers joined forces into the HAIC-HIWC international collaboration launched in 2012. Two flight campaigns were conducted in the high ice water content areas of tropical mesoscale convective systems in order to characterize this environment conducive to ice crystal icing. Statistics on cloud microphysical properties, such as Ice Water Content (IWC) or Mass Median Diameter (MMD), derived from the dataset of in situ measurements are now being used to support icing certification rulemaking and anti-icing systems design (engine and air data probe) activities. This technical paper focuses on methodological aspects of the derivation of MMD. MMD are estimated from PSD and IWC using a multistep process in which the mass retrieval method is a critical step. Complementary to previous studies reporting on MMD values calculated from the HAIC-HIWC dataset, this paper
Coutris, Pierre, Schwarzenboeck, Alfons, Leroy, Delphine, Grandin, Alice, Dezitter, Fabien, Strapp, J. Walter
Four Years of Testing to AS55622019-01-195706/10/2019
With the publication of SAE AS5562 in 2015, icing wind tunnel test facilities have upgraded their operating environments and instrumentation to meet the client demand to test to this new standard. Nearing four years of testing and development to this standard, numerous questions and challenges have arisen that industry has addressed on an individual basis but not in a common format for all. This paper addresses some of the known challenges in an effort to apply AS5562 consistently across industry and provide clarity to all users.
Matheis, Brian D., Clark, Catherine, Whalen, Mac
Testing of Elastomer Icephobic Coatings in the AIWT: Lessons Learned2019-01-199406/10/2019
A study has been conducted into icephobic properties of some highly durable “off-the-shelf” elastomer materials using a rotating ice adhesion test rig installed in the NRC’s Altitude Icing Wind Tunnel. This enabled the formation of ice at environmental conditions similar to those experienced during in-flight icing encounters. Initially, the tests indicated some very positive results with ice adhesion shear stress as low as 8KPa. On further examination, however, it became apparent that the test preparation process, in which the samples were cleaned with an ethanol alcohol solution, influenced the results due to absorption and prolonged retention of the cleaning fluid. The uptake of the ethanol alcohol solution by the elastomer was found to be a function of the surface temperature and remained absorbed into the coating during the ice accretion process changing the characteristics of the coating in such a way that led to a reduction in the ice/surface bond strength.
Orchard, David, Chevrette, Gislain, Maillard, Damien, Khoun, Lolei
Influence of Freestream Temperature on Ice Accretion Roughness2019-01-199306/10/2019
The influence of freestream static temperature on roughness temporal evolution and spatial variation was investigated in the Icing Research Tunnel (IRT) at NASA Glenn Research Center. A 53.34 cm (21-in.) NACA 0012 airfoil model and a 152.4 cm (60-in.) HAARP-II business jet airfoil model were exposed to Appendix C clouds for fixed exposure times and thus fixed ice accumulation parameter. For the base conditions, the static temperature was varied to produce different stagnation point freezing fractions. The resulting ice shapes were then scanned using a ROMER Absolute Arm system and analyzed using the self-organizing map approach of McClain and Kreeger. The ice accretion prediction program LEWICE was further used to aid in interrogations of the ice accretion point clouds by using the predicted surface variations of local collection efficiency. The resulting equivalent sand-grain roughness heights predicted using the correlation of Flack and Schultz are compared to the roughness
McClain, Stephen T., Vargas, Mario, Tsao, Jen-Ching, Broeren, Andy
Korean Utility Helicopter KUH-1 Icing Certification Program2019-01-198906/10/2019
The KUH-1 Surion is a twin-engine utility helicopter designed and developed jointly by Korea Aerospace Industries (KAI) and Airbus Helicopters primarily for the Republic of Korea Army (ROKA). Following customer requirements, KAI launched a program aimed at the military qualification of the KUH-1 for flight in icing conditions following tailored airworthiness certification criteria based on 14 CFR Part 29 and DEF STAN 00-970. The Netherlands Aerospace Centre (NLR) became involved in the program on the eve of the first icing flight test campaign performed in the winter of 2015/2016. NLR has supported all subsequent test activities and the finding of compliance in close collaboration with KAI and certain suppliers. The test activities performed include 1) component-level development and qualification icing wind tunnel testing at Cox & Co in Long Island, NY, 2) icing qualification testing of the engine air intake ice protection system at Rail Tec Arsenal (RTA) in Vienna, Austria, 3
van 't Hoff, Stefan, Lammers, Karel, Hwang, Yoo Sang, Kim, Jik Soo, Kim, Kyung Sam
An Assessment of LEWICE Roughness and Convection Enhancement Models2019-01-197706/10/2019
During aircraft design and certification, in-flight ice accretions are simulated using ice prediction codes. LEWICE, the ice accretion prediction code developed by NASA, employs a time-stepping procedure coupled with a thermodynamic model to calculate the location, size and shape of an ice accretion. LEWICE has been extensively validated for a wide range of icing conditions. However, continuing improvements to LEWICE predictive capabilities require better understandings of 1) the fundamental physics of turbulent flow generated by ice accretion roughness during an icing event and 2) the mechanisms responsible for convective enhancement of real ice accretion roughness. Recent experiments in the Icing Research Tunnel (IRT) at NASA Glenn Research Center have enabled significant insights into the nature of ice accretion roughness spatial and temporal variations. Other recent investigations have employed scans from the IRT to generate scaled test surfaces to investigate convection
Shannon, Timothy, McClain, Stephen T.
Ice Crystal Icing Test Design and Execution for the ALF502 Vane Segment in the NRC RATFac Cascade Rig2019-01-192506/10/2019
Understanding the behaviour of ice crystal ice (ICI) accretion and shedding inside an aircraft engine is important for safe and reliable engine operation in flight and to meet new airworthiness regulations. A significant advancement in this understanding came from two engine test campaigns carried out on a Honeywell ALF502 turbofan, led by the Ice Crystal Consortium (ICC) and NASA. However, it is often desirable to conduct smaller scale component level tests to both decrease costs and increase the amount of data obtainable, given a component is more accessible when removed from an engine and therefore easier to instrument and observe. That was the purpose of the work discussed in this paper where a segment of an ALF502 low pressure exit guide vane ring was installed in the NRC RATFac ICI cascade rig. The existing cascade rig was modified to accommodate the vane segment which allowed for the instrumentation already available on the rig to be used to characterize the ICI environment. The
Fuleki, Dan, Neuteboom, Martin, Chalmers, Jennifer
An Experimental Study to Evaluate the Droplet Impinging Erosion Characteristics of an Icephobic, Elastic Soft Surface2019-01-199706/10/2019
Elastic soft material/surface, such as Polydimethylsiloxane (PDMS), is a perspective, useful and low-cost hydrophobic and icephobic coating. While it has been reported to have good mechanical durability, its erosion durability under the high impacting of water droplets pertinent to aircraft inflight icing phenomena has not been explored. In this study, the droplet imping erosion characteristics of an icephobic PDMS surface/material is evaluated systematically upon the dynamic impinging of water droplets at different impact velocities (~ up to 75m/s), in comparison with other state-of-the-art icephobic materials/surfaces, such as superhydrophobic surface (SHS) and slippery liquid-infused porous surface (SLIPS). Surprisingly, the contact angle (CA) of the elastic PDMS is shown to have an over 20° increase (from 105° to 128°), which represents better hydrophobicity, after the erosion test which is mainly contributed to the higher roughness of the eroded PDMS surface. As for the
Ma, Liqun, Zhang, Zichen, Liu, Yang, Hu, Hui
Numerical Investigation of the NASA Glenn Propulsion Systems Laboratory2019-01-192406/10/2019
NASA Glenn Research Center’s Propulsion Systems Laboratory (PSL) allows ice-crystal ice accretion tests on jet engines. This pressurized wind tunnel facility allows engines to be operated at flight altitudes and temperatures. Steady state and unsteady computational fluid dynamics simulations were performed for the PSL geometry, including the spray bars with their supports, and the converging duct section. These simulation results help to characterize the performance of the tunnel and are important for understanding the flow and particle behavior leading up to the engine test section. The results indicate complex flow structures, with vortex shedding and non-uniform flow features. Flow separation is observed in several regions. Several flow features and vortices are seen to persist to the duct exit plane where the fan section of a jet engine would be mounted for testing. Unsteady simulations show that periodic vortex shedding is created by the spray bars, and that the generated
Feier, Ioan
Separating-Reattaching Flows Over an Iced Airfoil2019-01-194606/10/2019
Delayed Detached Eddy Simulations (DDES) of separating-reattaching flows on the suction side of an ice-contaminated airfoil were conducted. A single-section straight-wing NACA23012 airfoil with leading-edge ice was studied. The geometry represents a realistic glaze horn-ice contamination obtained during the icing test campaigns described in [1], which has aerodynamic data for comparison. The three-dimensional transient flow behavior was simulated using the open-source flow solver OVERFLOW, version 2.2l [2] developed by NASA Langley Research Center. Configurations at three angles of attack that exhibit unsteady flow behavior starting with the bursting angle were examined at Mach number of 0.18 and Reynolds number of 1.8x106. As the stall angle was approached the aerodynamic performance parameters displayed large-scale unsteadiness where periods of attached and separated flows were observed. The time-averaged results show good agreement with the aerodynamic test data. The calculated
Oztekin, Ezgi, Riley, James
Characterization of Mode-II Interfacial Fracture Toughness of Ice/Metal Interfaces2019-01-194706/10/2019
Airborne, marine and ground structures are vulnerable to atmospheric icing in cold weather operation conditions. Most of the ice adhesion-related work have focused on the mechanical ice removal strategies because of practical considerations, while limited literature is available for fundamental understanding of the ice adhesion process. Here, we present a fracture mechanics-based approach to characterize interfacial fracture parameters for the shear behavior of a typical ice/aluminum interface. An experimental framework employing two complementary tests (1) lap shear and (2) shear push-out tests was introduced to assess the mode-II fracture parameters for the selected aluminum/ice interface. Both analytical (shear-lag analysis) and numerical (finite element analysis incorporating cohesive zone method) models were used to evaluate shear fracture parameters. The combined experimental and numerical results, as well as surveying published results for lap shear and 0° cone tests showed that
Yavas, Denizhan, Bastawros, Ashraf, Dawood, Bishoy, Giuffre, Christopher
Equivalent Sand Grain Roughness Correlation for Aircraft Ice Shape Predictions2019-01-197806/10/2019
Many uncertainties in an in-flight ice shape prediction are related to convection heat transfer coefficient, which in turn depends on the flow, turbulence and laminar/turbulent transition models. The height of ice roughness element used to calculate the Equivalent Sand Grain Roughness height (ESGR) is a very important input of the turbulence model as it strongly influences the shape of the accreted ice. Unfortunately, for in-flight icing, the ESGR is unknown and generally calculated using semi-empirical models or empirical correlations based on a particular ice shape prediction code. Each ice shape prediction code is unique due to the models and correlations used and the numerical implementation. Ice roughness correlations do not have the same effect in each ice shape prediction code. A new approach to calculate the ESGR correlation taking into consideration the particularities of the ice shape prediction code is developed, calibrated and validated. This new approach derives a
Fortin, Guy
A Novel Heating-Coating Hybrid Strategy for Wind Turbine Icing Mitigation2019-01-202906/10/2019
The electro-thermal method is most commonly used for wind turbine anti-/de-icing. The upmost drawback of such systems is the high power consumption. In the present study, we proposed to use a durable slippery liquid-infused porous surface (SLIPS) to effectively reduce the power requirement of the heating element during the anti-/de-icing process. The explorative study was conducted in the Icing Research Tunnel at Iowa State University (ISU-IRT) with a DU91-W2-250 wind turbine blade model exposed under severe icing conditions. During the experiments, while a high-speed imaging system was used to record the dynamic ice accretion process, an infrared (IR) thermal imaging system was also utilized to achieve the simultaneous surface temperature measurements over the test model. In comparison to the traditional electrical heating strategies to brutally heat massive area of entire turbine blades, a novel heating-coating hybrid strategy, i.e., combining a leading-edge (LE) heating element to
Gao, Linyue, Ma, Liqun, Liu, Yang, Hu, Hui
A Parametric Study on the Thermodynamic Characteristics of DBD Plasma Actuation and Its Potential for Wind Turbine Icing Mitigation2019-01-203106/10/2019
Wind turbine icing represents the most significant threat to the integrity of wind turbines in cold weather. Ice formation on wind turbine blades was found to cause significant aerodynamic performance degradation, resulting in a substantial drop in energy production. Recently developed Dielectric barrier discharge (DBD) plasma-based anti-/de-icing systems showed very promising effects for aircraft icing mitigation. In this present study, DBD plasma-based anti-/de-icing systems were employed for wind turbine icing mitigation. First, a comprehensive parametric study is conducted to investigate the effects of various DBD plasma actuation parameters on its thermodynamic characteristics. An infrared (IR) thermal imaging system is used to quantitatively measure the temperature distributions over the test plate under various test conditions. DBD plasma actuators are embedded over the surface of a DU91-W2-250 wind turbine blade model, and a series of experiments were conducted by using the
Kolbakir, Cem, Gao, Linyue, Liu, Yang, Hu, Hui
Advanced Nanocomposite Low Adhesion Icephobic Coating for Aerospace Applications2019-01-199606/10/2019
Icing is a major safety issue for flight operations in the civil, defense and space sectors. Ice can form on critical components during takeoff/landing, or while in service, depending on prevailing weather conditions. Aircraft manufacturers relies on two different approaches to prevent ice buildup using an active anti-icing system to melt ice buildup or deicing chemicals/ice repellent surface to minimize the buildup ice. The use of active anti-icing systems offers good protection, however can add significant penalty to overall weight, energy consumption and cost. Aerospace industry is in need for an advanced ice repellent surface to effectively minimize ice buildup on critical components with no modification to existing design can provide significant relief to ice prone systems. In this paper, Oceanit will present its most advanced nanocomposite low ice adhesion icephobic coating technology that was developed and demonstrated for application on metallic surfaces to provide the lowest
Veedu, Vinod, Thapa, Sumil, Arumugam, Ganesh Kumar
Total Temperature Measurements in Icing Cloud Flows Using a Rearward Facing Probe2019-01-192306/10/2019
This paper reports on temperature and humidity measurements from a series of ice-crystal icing tunnel experiments conducted in June 2018 at the Propulsion Systems Laboratory at the NASA Glenn Research Center. The tests were fundamental in nature and were aimed at investigating the icing processes on a two-dimensional NACA0012 airfoil subjected to artificially generated icing clouds. Prior to the tests on the airfoil, a suite of instruments, including total temperature and humidity probes, were used to characterize the thermodynamic flow and icing cloud conditions of the facility. Two different total temperature probes were used in these tests which included a custom designed rearward facing probe and a commercial self-heating total temperature probe. The rearward facing probe, the main total temperature probe, is being designed to reduce and mitigate the contaminating effects of icing and ingestion of ice crystals and water droplets at the probe’s inlet. The probe also serves as an air
Agui, Juan H., Struk, Peter, Bartkus, Tadas
NRC Particle Detection Probe: Results and Analysis from Ground and Flight Tests2019-01-193306/10/2019
High altitude ice crystals are causing in-service events in excess of one per month for commercial aircraft. The effects include air data probes malfunctioning (pitot pressure and total air temperature in particular), and uncommanded engine power loss or flameout events. The National Research Council Canada (NRC) has developed a particle detection probe (PDP) that mounts on the fuselage of aircraft to sense and quantify the ice crystals in the environment. The probe is low-power and non-intrusive. This paper presents the results of ground and flight testing of this probe. Results are presented for ground testing in a sea level ice crystal wind tunnel and an altitude icing tunnel capable of generating both ice crystal and super-cooled liquid. The PDP was operated on several flight campaigns and the results of two will be presented. The first was on board a NRC Convair 580 aircraft in French Guiana (FG) and the second was on an Airbus operated A340 research aircraft in Darwin and Reunion
Davison, Craig, Chalmers, Jennifer, Fuleki, Dan
Electromechanical Resonant Ice Protection Systems: How to Favour Fractures Propagation2019-01-203206/10/2019
Many researches focus on piezoelectric ice protection systems with the objectives to develop light and low consumption resonant electromechanical systems for de-icing. These systems use the vibrations generated by piezoelectric actuators at resonance frequencies to produce shear stress at the interface between the ice and the support or to produce tensile stress in the ice. This article presents experimental results of de-icing tests performed with resonant piezoelectric systems that generate amplitudes of vibrations to exceed ice tensile strength or ice/support adhesive shear strength. The tests show that fractures are initiated but that the ice is not always completely detached. A methodology based on the energy release rate is presented to enable a better understanding of fractures initiation and propagation. The last section part of the article is dedicated to the study of a substrate made of a sandwich structure with a honeycomb panel in order to maximize fractures propagation
Rouset, Pierrick, Pommier-Budinger, Valérie, Budinger, Marc
ICICLE: A Model for Glaciated & Mixed Phase Icing for Application to Aircraft Engines2019-01-196906/10/2019
High altitude ice crystals can pose a threat to aircraft engine compression and combustion systems. Cases of engine damage, surge and rollback have been recorded in recent years, believed due to ice crystals partially melting and accreting on static surfaces (stators, endwalls and ducting). The increased awareness and understanding of this phenomenon has resulted in the extension of icing certification requirements to include glaciated and mixed phase conditions. Developing semi-empirical models is a cost effective way of enabling certification, and providing simple design rules for next generation engines. A comprehensive ice crystal icing model is presented in this paper, the Ice Crystal Icing ComputationaL Environment (ICICLE). It is modular in design, comprising a baseline code consisting of an axisymmetric or 2D planar flowfield solution, Lagrangian particle tracking, air-particle heat transfer and phase change, and surface interactions (bouncing, fragmentation, sticking). In
Bucknell, Alexander, McGilvray, Matthew, Gillespie, David, Yang, Xin, Jones, Geoffrey, Collier, Benjamin
Wind Tunnel Measurements of Simulated Glaciated Cloud Conditions to Evaluate Newly Developed 2D Imaging Probes2019-01-198106/10/2019
Instrumentation that has been used for characterization of mixed-phase and glaciated conditions in the past, like the OAP probes, are subject to errors caused by variations in diffraction on the images away from the object plane and by the discrete nature of their particle detection and sizing. Correction methods are necessary to consider their measurements adequate for high ice water content (IWC) environments judged to represent a significant safety hazard to propellers and turbofan engine operability and performance. For this reason, within the frame of EU FP7 HAIC project, instrumentation characterization and validation is considered a major element need for successful execution of flight tests campaigns. Clearly, instrumentation must be sufficiently reliable to assess the reproducibility of artificial clouds with high ice water content generated in icing tunnels. Instruments are required to measure these conditions with a sufficient level of accuracy for the purposes of the
Esposito, Biagio M., Bachalo, William D., Leroy, Delphine, Schwarzenboeck, Alfons, Jurkat, Tina, Voigt, Christiane, Bansmer, Stephan
Predicted Ice Shape Formations on a Boundary Layer Ingesting Engine Inlet2019-01-202506/10/2019
Computational ice shapes were generated on the boundary layer ingesting engine nacelle of the D8 Double Bubble aircraft. The computations were generated using LEWICE3D, a well-known CFD icing post processor. A 50-bin global drop diameter discretization was used to capture the collection efficiency due to the direct impingement of water onto the engine nacelle. These discrete results were superposed in a weighted fashion to generate six drop size distributions that span the Appendix C and O regimes. Due to the presence of upstream geometries, i.e. the fuselage nose, the trajectories of the water drops are highly complex. Since the ice shapes are significantly correlated with the collection efficiency, the upstream fuselage nose has a significant impact on the ice accretion on the engine nacelle. These complex trajectories are caused by the ballistic nature of the particles and are thus exacerbated as particle size increases. Shadowzones are generated on the engine nacelle, and due to
Porter, Christopher
A New Wind Tunnel Facility for Ice Crystal Icing Experiments2019-01-192606/10/2019
The design and characterization of a new ice crystal icing wind tunnel facility is introduced through this work. The arrangement proposed in this work involves water droplet freeze-out using liquid nitrogen evaporation followed by natural particle melting through dilution with warm air. The viability of the concept was first demonstrated theoretically using a conservation of energy analysis. Thermodynamic performance of the facility is dictated largely by the availability of the liquid nitrogen, and in order to establish a facility with modest operating costs, the proposed operation specified using a maximum of 20 liter of liquid nitrogen per run with a maximum duration of two minutes. The target operating conditions for the facility were: flow speed around 50 m/s, temperatures around 0 °C, and total water content up to 10 g/m3 with melting ratio up to 0.2. Experimental results have demonstrated a generally favorable agreement with the energy equation analysis, and with results from
Saeed, Ramiz, Buttsworth, David, Saleh, Khalid
Ranking of Thick Ice Shapes Based on Numerical Simulation for Certification2019-01-194406/10/2019
The objective of this paper is to present a numerical method to rank thick ice shapes for aircraft by comparing the ice accretion effects for different icing scenarios in order to determine the more critical ice shape. This ranking allows limiting the demonstration of the aerodynamic characteristics of the aircraft in iced condition during certification to a reduced number of ice shapes. The usage of this numerical method gives more flexibility to the determination of the critical ice shapes, as it is not dependent of the availability of physical test vehicles and/or facilities. The simulation strategy is built on the Lattice Boltzmann Method (LBM) and is validated based on a representative test case, both in terms of aircraft geometry and ice shapes. Validation against existing experimental results shows the method exhibits an adequate level of reliability for the ranking of thick ice shapes.
Barth, Marcus, Degrigny, Johan, Brown, James, Tezok, Fatih, Lewis, Richard, Alegre, Nathalie, Barrios-Garcia, Isaac
A Three-Layer Thermodynamic Model for Ice Crystal Accretion on Warm Surfaces: EMM-C2019-01-196306/10/2019
Ingestion of high altitude atmospheric ice particles can be hazardous to gas turbine engines in flight. Ice accretion may occur in the core compression system, leading to blockage of the core gas path, blade damage and/or flameout. Numerous engine powerloss events since 1990 have been attributed to this mechanism. An expansion in engine certification requirements to incorporate ice crystal conditions has spurred efforts to develop analytical models for phenomenon, as a method of demonstrating safe operation. A necessary component of a complete analytical icing model is a thermodynamic accretion model. Continuity and energy balances are performed using the local flow conditions and the mass fluxes of ice and water that are incident on a surface to predict the accretion growth rate. In this paper, a new thermodynamic model for ice crystal accretion is developed through adaptation of the Extended Messinger Model (EMM) from supercooled water conditions to mixed phase conditions (ice
Bucknell, Alexander, McGilvray, Matthew, Gillespie, David, Jones, Geoffrey, Collier, Benjamin
SLD and Ice Crystal Discrimination with the Optical Ice Detector2019-01-193406/10/2019
In response to new safety regulations regarding aircraft icing, Collins Aerospace has developed and tested an Optical Ice Detector (OID) capable of discriminating among icing conditions appropriate to Appendix C and Appendix O of 14 CFR Part 25 and Appendix D of Part 33. The OID is a short-range, polarimetric lidar that samples the airstream up to ten meters beyond the skin of the aircraft. The intensity and extinction of the backscatter light correlate with bulk properties of the cloud, such as water content and phase. Backscatter scintillation (combined with the outside air temperature from another probe) signals the presence of supercooled large droplets (SLD) within the cloud-a capability incorporated into the OID to meet the requirements of Appendix O. Recent laboratory and flight tests of the Optical Ice Detector have confirmed the efficacy of the OID to discriminate among the various icing conditions. Drizzle-sized droplets, mixed with a small droplet cloud in the Collins Cloud
Anderson, Kaare J., Ray, Mark D.
Computational Simulation of an Electrically Heated Ice Protection System for Composite Leading Edges of Aircraft2019-01-204106/10/2019
The performance of an electrically heated aircraft ice protection system for a composite leading edge was evaluated. The composite leading edge of the model is equipped with a Ni alloy resistance heater. A state-of-the-art icing code, FENSAP-ICE, was used for the analysis of the electrothermal de-icing system. Computational results, including detailed information of conjugate heat transfer, were validated with experimental data. The computational model was then applied to the composite leading edge wing section at various metrological conditions selected from FAR Part 25 Appendix C.
Lawrence Raj, Prince Raj, Jeong, Hojin, Roy, Rene, Kweon, Jin-Hwe, Myong, Rho Shin
Summary of the High Ice Water Content (HIWC) RADAR Flight Campaigns2019-01-202706/10/2019
NASA and the FAA conducted two flight campaigns to quantify onboard weather radar measurements with in-situ measurements of high concentrations of ice crystals found in deep convective storms. The ultimate goal of this research was to improve the understanding of high ice water content (HIWC) and develop onboard weather radar processing techniques to detect regions of HIWC ahead of an aircraft to enable tactical avoidance of the potentially hazardous conditions. Both HIWC RADAR campaigns utilized the NASA DC-8 Airborne Science Laboratory equipped with a Honeywell RDR-4000 weather radar and in-situ microphysical instruments to characterize the ice crystal clouds. The purpose of this paper is to summarize how these campaigns were conducted and highlight key results. The first campaign was conducted in August 2015 with a base of operations in Ft. Lauderdale, Florida. Ten research flights were made into deep convective systems that included Mesoscale Convective Systems (MCS) near the Gulf
Ratvasky, Thomas, Harrah, Steven, Strapp, J. Walter, Lilie, Lyle, Proctor, Fred, Strickland, Justin, Hunt, Patricia, Bedka, Kristopher, Diskin, Glenn, Nowak, John B., Bui, T. P., Bansemer, Aaron, Dumont, Christopher
Items per page:
1 – 50 of 300