Browse Topic: Icing and ice detection

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Design Solutions for Ice-Induced CNG Filling Failures- Field Issue Resolution through Filter Geometry and Seal Material Reengineering2026-26-051501/16/2026
This study investigates the phenomenon of receptacle icing during Compressed Natural Gas (CNG) refueling at filling stations, attributing the issue to excessive moisture content in the gas. The research examines the underlying causes, including the Joule-Thomson effect, filter geometries, and their collective impact on flow interruptions. A comprehensive test methodology is proposed to simulate real-world conditions, evaluating various filter types, seal materials and moisture levels to understand their influence on icing and flow cessation. The findings aim to offer ideas for reducing icing problems. This will improve the reliability and safety of CNG refueling systems.
Virmani, Nishant, Sawant, Shivraj Madhukar, C R, Abhijith
Wetting Prediction of Power Train Components under the Influence Moving Components using Smooth Particle Hydrodynamics2026-26-038401/16/2026
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 puddle 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
Wind-tunnel investigation of snow/ice drag on a 30%-scale DrivAer model2026-01-060404/07/2025
Wind-tunnel tests were conducted using a 30%-scale DrivAer model, in estateback and notchback rear-geometry configurations, to investigate aerodynamic performance changes associated with snow and ice buildup on passenger vehicles. Around 20 snow/ice accumulation patterns were tested, at a Reynolds number of 2.8 million based on model wheelbase, for each of the notchback and estateback variants. 5 additional patterns were tested on the estateback with roof-rack support bars. Snow accumulation was modelled with foam, while ice accumulation was simulated with aluminum tape hand-formed to the desired shape. A simulated full-scale snow thickness of 58 mm on the hood, roof and trunk increased the wind-averaged drag coefficient by 16% for both model variants. With 90 mm of snow, the drag of the estateback variant increased by 19%. Drag changes increased with, but were not proportional to, snow thickness. Chamfered front and rear edges, representing windblown shapes, reduced the drag penalty
de Souza, Fenella, McAuliffe, Brian
Calibration and Acceptance of Icing Wind TunnelsARP5905A (Current)01/21/2025
This SAE Aerospace Recommended Practice (ARP) provides recommended practices for the calibration and acceptance of icing wind tunnels to be used in testing of aircraft components and systems and for the development of simulated ice shapes. This document is not directly applicable to air-breathing propulsion test facilities configured for the purposes of engine icing tests, which are covered in AIR6189. This document also does not provide recommended practices for creating Supercooled Large Drop (SLD) or ice crystal conditions, since information on these conditions is not sufficiently mature for a recommended practice document at the time of publication of ARP5905A. Use of facilities as part of an aircraft’s ice protection Certification Plan should be reviewed and accepted by the applicable regulatory agency prior to testing. Following acceptance of a test plan, data generated in these facilities may be submitted to regulatory agencies for use in the certification of aircraft ice
AC-9C Aircraft Icing Technology Committee
Optimizing the Capacity of Dozer Blade with Hydraulic Foldable Wings to Enhance Productivity2024-28-026812/05/2024
Crawler Dozers play a critical role in global construction, mining and industrial sectors, performing essential tasks like pushing the material, grading, leveling and scraping. In the highly competitive dozer market, meeting the growing demand for increased productivity requires strategies to enhance blade capacity and width. Dozer operations involve pushing the material and dozing, where blade capacity significantly influences performance. Factors such as mold board profile, blade height, and width impact the blade capacity which are crucial for productivity in light weight applications such as snow removal and dirt pushing. Blade width is also pivotal for grading and leveling tasks. Traditional blade designs, like straight or fixed U-type blades, constrain operator flexibility, limiting overall productivity. The integration of hydraulic-operated foldable wings on both sides of the blade offers the adaptability to adjust blade capacity which also helps to reduce material spillage
Sahoo, Jyoti Prakash, Sarma, Neelam Kumar
Minimum Operational Performance Specification for Remote On-Ground Ice Detection SystemsAS5681C (Current)08/12/2024
This SAE Aerospace Standard (AS)/Minimum Operational Performance Specification (MOPS) specifies the minimum performance requirements of remote on-ground ice detection systems (ROGIDS). These systems are ground based. They provide information that indicates whether frozen contamination is present on aircraft surfaces. Section 1 provides information required to understand the need for the ROGIDS, ROGIDS characteristics, and tests that are defined in subsequent sections. It describes typical ROGIDS applications and operational objectives and is the basis for the performance criteria stated in Sections 3 through 5. Section 2 provides reference information, including related documents, definitions, and abbreviations. Section 3 contains general design requirements for the ROGIDS. Section 4 contains the Minimum Operational Performance Requirements for the ROGIDS, which define performance in icing conditions likely to be encountered during ground operations. Section 5 describes environmental
G-12HOT Holdover Time Committee
Ice Detection from Microwave SensorsTBMG-5064805/01/2024
Ice build-up on aircraft and wind turbines can impact the safety and efficiency of their systems.
Differentiation between Appendix O and Appendix C Icing Conditions in Flight Using the Collins Ice Differentiator System2024-01-193303/05/2024
Protecting against atmospheric icing conditions is critical for the safety of aircraft during flight. Sensors and probes are often used to indicate the presence of icing conditions, enabling the aircraft to engage their ice protection systems and exit the icing cloud. Supercooled large drop icing conditions, which are defined in Appendix O of 14 CFR Part 25, pose additional aircraft certification challenges and requirements as compared to conventional icing conditions, which are defined in Appendix C of 14 CFR Part 25. For this reason, developing sensors that can not only indicate the presence of ice, but can also differentiate between Appendix O and Appendix C icing conditions, is of particular interest to the aviation industry and to federal agencies. Developing detectors capable of meeting this challenge is the focus of SENS4ICE, a European Union sponsored project. While participating in the SENS4ICE Project, Collins Aerospace has developed an ice detection and differentiation
Hamman, Matthew, Gelao, Giancarlo, Ridouane, El Hassan, Chabukswar, Rohan, Botura, Galdemir
Assessment of Noncommercial Icing Prediction Capabilities for Army ApplicationsTBMG-4966612/01/2023
Historically, smaller Unmanned Aerial Systems (UAS), such as Class 2 RQ-1B Raven and Class 3 RQ-7Bv2 Shadow, have been restricted to not be approved to fly in icing conditions under the assumption that any ice accretion would cause an unacceptable risk of loss of the aircraft. However, interest exists in better understanding potential icing accretion on UAS to determine if less extreme icing conditions could result in only partial degradation and not total loss of the vehicle for the purpose of expanding approved flight envelopes. Icing accretion can be tested during a flight test, which is considered unacceptable due to lack of controlled conditions and risk to the UAS or in a controlled experiment, by using wind tunnel testing to evaluate a single icing condition. Cryogenic wind tunnel tests, such as those conducted at the National Aeronautical and Space Administration (NASA) Glenn Icing Research Tunnel (IRT), Cleveland, OH, as shown in figures 1 and 2, are prohibitively expensive
Assessment of Noncommercial Icing Prediction Capabilities for Army Applications23AERP12_1012/01/2023
Ice prediction capabilities for Unmanned Aerial Systems (UAS) is of growing interest as UAS designs and applications become more diverse. This report summarizes the current state-of-the-art in modeling aircraft icing within a computational framework as well as a recent U.S. Army DEVCOM AvMC effort to evaluate ice prediction models for current use and future integration into the Computational Research and Engineering Acquisition Tools and Environments (CREATE) Air Vehicle (AV) framework. U.S. Army Combat Capabilities Development Command, Redstone Arsenal, Alabama Historically, smaller Unmanned Aerial Systems (UAS), such as Class 2 RQ-1B Raven and Class 3 RQ-7Bv2 Shadow, have been restricted to not be approved to fly in icing conditions under the assumption that any ice accretion would cause an unacceptable risk of loss of the aircraft. However, interest exists in better understanding potential icing accretion on UAS to determine if less extreme icing conditions could result in only
Brake Squeal – Digital Twinning of a Brake Dynamometer2023-01-188411/05/2023
Brake squeal is a common phenomenon across all types of vehicles. It becomes prominent in the absence of other noise sources, as in the case of electric vehicles. Earlier simulation attempts date back to late nineties and early 2000s. Identification of unstable modes of the coupled system of brake rotor and pads, and occasionally some caliper components, was the primary goal. Simulating the rotation of the rotor along with squeezing of the pads was attempted in a multi-body dynamics tools with flexible representation of rotor and pads. Though this gave some insights into the dynamics of stopping mechanism, squeal required capturing the nonlinearities of the contact in a more rigorous sense. Also, efforts were made to capture noise from vibrations using boundary- and finite- element methods [1]. In this attempt at digitalizing a brake dynamometer, the author used a nonlinear implicit solver to mimic the dynamics and transient vibro-acoustic solver to convert transient vibrations to
Kappagantu, Ramana
Aircraft Ground Deicing/Anti-Icing Communication Phraseology for Flightcrew and GroundcrewARP6257B (Current)09/15/2023
This SAE Aerospace Recommended Practice (ARP) establishes standard phraseology for the communication procedures during aircraft ground deicing/anti-icing operations.NOTE: The minimum requirements to accomplish an aircraft deicing/anti-icing operation are specified in AS6285.Clear concise standard phraseology between the groundcrew and flightcrew is an important part of the deicing/anti-icing process. It plays a key role in the overall safety of the deicing program. Historically, flightcrew and groundcrew have had to deal with differing communication scripts at multiple airport locations. This has led to unsafe situations, including aircraft moving before the deicing process has been fully completed.
G-12M Methods Committee
Experimental Investigation of a CRM65 Wingtip Mockup under Appendix C and Appendix O Icing Conditions2023-01-138606/15/2023
Research institutes and companies are currently working on 3D numerical icing tools for the prediction of ice shapes on an international level. Due to the highly complex flow situation, the prediction of ice shapes on three-dimensional surfaces represents a challenge. An essential component for the development and subsequent validation of 3D ice accretion codes are detailed experimental data from ice shapes accreted on relevant geometries, like wings of a passenger aircraft for example. As part of the Republic of Austria funded research project JOICE, a mockup of a wingtip, based on the National Aeronautics and Space Administration common research model CRM65 was designed and manufactured. For further detailed investigation of electro-thermal de-icing systems, various heaters and thermocouples were included. The mockup was investigated in the Icing Wind Tunnel of Rail Tec Arsenal in Vienna, Austria under various Appendix C and Appendix O icing conditions with and without activated
Puffing, Reinhard, Neubauer, Thomas, Moser, Richard, Hassler, Wolfgang, Schweighart, Simon, Ferschitz, Hermann, Diebald, Stefan, Breitfuss, Wolfgang, Kozomara, David
Numerical Study of Iced Swept-Wing Performance Degradation using RANS2023-01-140206/15/2023
This paper studies the level of confidence and applicability of CFD simulations using steady-state Reynolds-Averaged Navier-Stokes (RANS) in predicting aerodynamic performance losses on swept-wings due to contamination with ice accreted in-flight. The wing geometry selected for the study is the 65%-scale Common Research Model (CRM65) main wing, for which NASA Glenn Research Center’s Icing Research Tunnel has generated experimental ice shapes for the inboard, mid-span, and outboard sections. The reproductions at various levels of fidelity from detailed 3D scans of these ice shapes have been used in recent aerodynamic testing at the Office National d’Etudes et Recherches Aérospatiales (ONERA) and Wichita State University (WSU) wind tunnels. The ONERA tests were at higher Reynolds number range in the order of 10 million, while the WSU tests were in the order of 1 million. RANS CFD results for the lower-Reynolds 8.9% WSU model up to α = 10° were previously generated by University of
Ozcer, Isik, Pueyo, Alberto, Menter, Florian, Hafid, Sabrina, Yang, Hong
Modelling the Secondary Impingement of Supercooled Large Droplets in an Eulerian Environment2023-01-145906/15/2023
A model for the computation of the secondary trajectories of droplets has been implemented in the CIRA code Imp3d and validated with literature data. Aim of the paper is to present the model of secondary trajectories and to discuss the test cases performed.
Catalano, Pietro, Mele, Benedetto
UAV Icing: Numerical Simulation of Icing Effects on Wing and Empennage2023-01-138406/15/2023
In-flight icing can result in severe aerodynamic performance penalties for unmanned aerial vehicles. It is therefore important to understand to which extent ice will build up on fixed-wing unmanned aerial vehicles wings and empennages, namely rudder and elevator, and how this ice will impact the aerodynamic performance and limits the flight envelope. This work investigates numerically icing effects on wing and empennage over a wide range of icing parameters. This is conducted using the icing CFD code FENSAP-ICE on the Maritime Robotics PX-31 Falk UAV. Therefore, the 2D profiles of these airfoils, which are RG-15 for the wing and SD8020 for rudder and elevator, are investigated. The investigated angles of attack are between –5° and 14° in 0.5° increments. Furthermore, the icing conditions are chosen according to the FAA CS 25 Appendix C for continuous maximum and intermittent maximum icing. A broad range of temperatures, droplet median volumetric diameters, and the corresponding liquid
Lindner, Markus, Wallisch, Joachim, Hann, Richard
Planar Microwave Sensor for Localized Ice and Snow Sensing2023-01-143206/15/2023
Ice and snow accretion on aircraft surfaces imposes operational and safety challenges, severely impacting aerodynamic performance of critical aircraft structures and equipment. For optimized location-based ice sensing and integrated ‘smart’ de-icing systems of the future, microwave resonant-based planar sensors are presented for their high sensitivity and versatility in implementation and integration. Here, a conformal, planar complementary split ring resonator (CSRR) based microwave sensor is presented for robust detection of localized ice and snow accretion. The sensor has a modified thick aluminum-plate design and is coated with epoxy for greater durability. The fabricated sensor operates at a resonant frequency of 1.18 GHz and a resonant amplitude of -33 dB. Monitoring the resonant frequency response of the sensor, the freezing and thawing process of a 0.1 ml droplet of water is monitored, and a 60 MHz downshift is observed for the frozen droplet. Using an artificial snow chamber
Shah, Aaryaman, Niksan, Omid, Zarifi, Mohammad H.
Numerical Simulation of In-flight Icing by Water Droplets with Elevated Temperature2023-01-147706/15/2023
When conducting experiments in icing wind tunnels (IWTs), a significant question is to what extent the temperature of the water droplets generated by the spray system has converged to the static air temperature when the droplets impinge on the test object. This is a particularly important issue for large droplets, since the cooling rate of droplets decreases sharply with increasing diameter. In this paper, on the one hand, realistic droplet temperature distributions in the measurement section of the Rail Tec Arsenal IWT (located in Vienna) are computed by means of a numerical code which tracks the paths of the droplets from the spraying nozzle to the measurement section and simultaneously calculates their cooling rates. On the other hand, numerical icing simulations are performed to investigate to what extent the deviation of the droplet temperature from static air temperature influences icing and thermal anti-icing processes. For this purpose, three selected cases are analyzed – two
Hassler, Wolfgang, Breitfuß, Wolfgang, Rapf, Andreas, Fallast, Arno, Moser, Richard, Tramposch, Andreas, Ferschitz, Hermann, Puffing, Reinhard, Neubauer, Thomas
Icing Environment Comparisons for the Distinct Parts of Jet Aircraft2023-01-142906/15/2023
Distinct parts of the aircraft may be exposed to different icing conditions due to varying flow and ambient conditions around them. These differences can be easily noticed, especially when icing conditions on the external surface and inside the engine air intake are compared for a jet aircraft. In this paper, the icing conditions around these parts are matched to between them. The purpose of this comparison study is to evaluate the functionality of ice detectors, located inside the air inlets, in detecting icing conditions around external surfaces as well. These systems provide information to the flight crew and/or airplane systems concerning inflight icing. On jet fighter or trainer type aircraft, they are generally located inside the engine air intake that serve as a warning equipment for icing risks on the aircraft engine itself. Sometimes, their warnings are also valid for intake lip ice detection if they are properly located. However, the usage of this equipment for ice detection
Akbal, Omer, Ayan, Erdem, Murat, Canibek, Ozgen, Serkan
Design and Testing of an Indirect Ice Detection Methodology2023-01-149306/15/2023
Distinct atmospheric conditions containing supercooled large droplets (SLD) have been identified as cause of severe accidents over the last decades as existing countermeasures even on modern aircraft are not necessarily effective against SLD-ice. Therefore, the detection of such conditions is crucial and required for future transport aircraft certification. However, the reliable detection is a very challenging task. The EU funded Horizon 2020 project SENS4ICE targets this gap with new ice detection approaches and innovative sensor hybridization. The indirect ice detection methodology presented herein is key to this approach and based on the changes of airplane flight characteristics under icing influence. A performance-based approach is chosen detecting an abnormal flight performance throughout the normal operational flight. It is solely based on a priori knowledge about the aircraft characteristic and the current measurable flight state. This paper provides a proof of concept for the
Deiler, Christoph, Sachs, Falk
Additional Comparison of Ice Shapes on Full-Chord and Truncated Swept Wing Models from January 20222023-01-138706/15/2023
A research program was conducted to evaluate the effectiveness of icing tunnel hybrid model design. A hybrid design is where the full-scale leading edge of a wing section is maintained only to a certain percentage of the local chord, while the aft section of the model is redesigned into a shortened or truncated planform. An initial study was conducted in 2020 where the ice shape geometries on a full-chord length version of the swept CRM65 wing model were compared to those from the hybrid version of CRM65 that were obtained in the NASA Icing Research Tunnel in 2015. The results were reported in a 2021 paper. For most test conditions, the overall size and shape of the ice shapes compared well. However, the ice shapes from the full-chord model were generally slightly smaller than those from the hybrid model. A follow-on test was conducted in 2022 and obtained ice shapes on both full-chord and hybrid wing models during the same test campaign to eliminate the differences in the tunnel spray
Lee, Sam, Broeren, Andy
Numerical Investigation of Pressure Tube Anti-Icing Heat Transfer2023-01-144006/15/2023
This work presents the anti-icing simulation results from a pressure sensing probe. This study used various turbulence models to understand their influence in surface temperature prediction. A fully turbulence model and a transition turbulence model are considered in this work. Both dry air and icing conditions are considered for this study. The results show that at low Angle of Attack (AOA) both turbulence model results compared well and at higher AOA the results deviated. Overall, as AOA increases, the k-ꞷ SST model predicted the surface temperature colder than the Transition SST model result.
Thangavel, Sathish, Bajpai, Shivanshu
UAV Icing: Experimental Validation Data for Predicting ice Shapes at Low Reynolds Numbers2023-01-137206/15/2023
Icing is a severe hazard to aircraft and in particular to unmanned aerial vehicles (UAVs). One important activity to understand icing risks is the prediction of ice shapes with simulation tools. Nowadays, several icing computational fluid dynamic (CFD) models exist. Most of these methods have been originally developed for manned aircraft purposes at relatively high Reynolds numbers. In contrast, typical UAV applications experience Reynolds numbers an order of magnitude lower, due to the smaller airframe size and lower airspeeds. This work proposes a set of experimental ice shapes that can serve as validation data for ice prediction methods at low Reynolds numbers. Three ice shapes have been collected at different temperatures during an experimental icing wind tunnel campaign. The obtained ice shapes represent wet (glaze ice, −2 °C), mixed (−4 °C), and dry (rime ice, −10 °C) ice growth regimes. The Reynolds number is between Re=5.6…6.0×105, depending on the temperature. The ice shapes
Hann, Richard, Müller, Nicolas, Lindner, Markus, Wallisch, Joachim
Icing Qualification Wind Tunnel Test of Helicopter Engine with Inlet Barrier Filter Air Intake2023-01-138106/15/2023
Icing wind tunnel testing was performed as part of the Republic of Korea certification of the Light Civil Helicopter (LCH) for inadvertent flight in icing conditions. The test was aimed at the compliance demonstration of the engine and air intake with dry-media Inlet Barrier Filter (IBF) and was performed with an Arriel 2C2 engine in turbojet configuration. Testing took place at the sea level ambient pressure Large Climatic Wind Tunnel (CWT) at Rail Tec Arsenal (RTA) in Vienna, Austria, by an integrated test team comprising engineers from the Royal Netherlands Aerospace Centre (NLR), Korea Aerospace Industries (KAI), and Safran Helicopter Engines. The test matrix covered the AC29-2C Appendix C 10,000 ft icing envelope, as well as simulated ground icing conditions, considering both a clean and artificially contaminated IBF. Beyond the aforementioned certification conditions, exploratory testing was performed in conditions with Supercooled Large Droplets (SLD) and rain. The test set-up
van 't Hoff, Stefan, Lammers, Karel, Jung, Joo Hyun, Kim, Hyung Sik, Ressejac, Sandy
Identification of an Electric UAV Propulsion System in Icing Conditions2023-01-137806/15/2023
In-flight atmospheric icing is a severe hazard for propeller-driven unmanned aerial vehicles (UAVs) that can lead to issues ranging from reduced flight performance to unacceptable loss of lift and control. To address this challenge, a physics-based first principles model of an electric UAV propulsion system is developed and identified in varying icing conditions. Specifically, a brushless direct current motor (BLDC) based propeller system, typical for UAVs with a wing span of 1-3 meters, is tested in an icing wind tunnel with three accreted ice shapes of increasing size. The results are analyzed to identify the dynamics of the electrical, mechanical, and aerodynamic subsystems of the propulsion system. Moreover, the parameters of the identified models are presented, making it possible to analyze their sensitivity to ice accretion on the propeller blades. The experiment data analysis shows that the propeller power efficiency is highly sensitive to icing, with a 40% reduction in thrust
Løw-Hansen, Bogdan, Müller, Nicolas C., Coates, Erlend M., Johansen, Tor Arne, Hann, Richard
Scalability of GlennICE in a Parallel Environment2023-01-148206/15/2023
The Glenn Icing Computational Environment (GlennICE) is a computational tool designed to calculate ice growth on complex three-dimensional geometries using the input from a user-supplied computational fluid dynamics (CFD) solution for the geometry of interest. The most significant developments in the advancement of GlennICE have been investigating the convergence of the collection efficiency, efficiently finding trajectories, and improving the refinement methodology. Such developments have increased the efficiency of GlennICE for practical engineering application. With the increasing demand for applying GlennICE for more memory-intensive problems, the scalability of GlennICE has yet to be investigated. This paper is aimed at presenting a method to benchmark the scalability of GlennICE utilizing a relevant engineering problem within a parallel environment. This leads to the final goal of investigating whether an increase in the number of processors utilized results in a linear speedup
Sabri, Zaid, Porter, Christopher
Development and Validation Testing of the Collins Ice Differentiator System in App C and App O Icing Conditions2023-01-149006/15/2023
Protecting against atmospheric icing conditions is critical for the safety of aircraft during flight. Sensors and probes are often used to indicate the presence of icing conditions, enabling the aircraft to exit the icing cloud and engage their ice protection systems. Supercooled large drop (SLD) icing conditions, which are defined in Appendix O of 14 CFR Part 25, pose additional risk to aircraft safety as compared to conventional icing conditions, which are defined in Appendix C of 14 CFR Part 25. For this reason, developing sensors that can not only indicate the presence of ice, but can also differentiate between Appendix O (App O) and Appendix C (App C) icing conditions, is of particular interest to the aviation industry and to federal agencies. Developing a detector capable of meeting this challenge is the focus of SENS4ICE, a European Union sponsored project. This paper summarizes the work that was done to develop the Collins Ice Differentiator System, an ice detection and
Hamman, Matthew, Ridouane, El Hassan, Gelao, Giancarlo, Chabukswar, Rohan, Botura, Galdemir
Ice Protection System Design for the Next Generation Civil Tiltrotor Engine Intake2023-01-137406/15/2023
This paper focuses on the design of the thermoelectric ice protection system (IPS) for the engine air intake of the Next Generation Civil Tiltrotor (NGCTR), a demonstrator under development in Leonardo Helicopters. A specific IPS design strategy for the novel intake configuration is proposed. The main constraint which driven the design strategy is a maximum power of 10.6 kW available for the full intake IPS system. The IPS was designed for safe aircraft operations within the Appendix-C icing envelope. The numerical approach adopted to perform the design and the resulting IPS concept are presented. Calculations of the required IPS heat fluxes revealed that maintaining running wet conditions on the entire intake surface is not feasible due to the limitation to the maximum IPS power demand. Therefore, a de-icing IPS design strategy is proposed. The anti-icing mode is adopted only on the lip region to avoid formation of ice caps whereas de-icing zones are defined within the intake duct
Tormen, Damiano, Zanon, Alessandro, De Gennaro, Michele
Predicting the Collection Efficiency on a Generic Rotor Blade with a Three-Dimensional Eulerian Particle Solver2023-01-146906/15/2023
Ice accretion on helicopter rotor blades when flying through supercooled droplet clouds can severely affect aerodynamic properties and pose a significant threat to flight safety. In the design phase, manufacturers commonly use 2D or quasi-3D simulations to predict potential ice accretion, which are more economical than fully 3D approaches. However, these methods frequently encounter accuracy issues when predicting the precise amount of ice accretion because the 3D flow field significantly influences droplet trajectories and, as a result, impingement and accreted mass. For this study the Eulerian particle solver of the icing software DICEPS was upgraded from 2D to 3D using second-order schemes, ensuring numerical stability on unstructured mesh configurations. Validation of the 3D modifications was performed by comparing numerical results of the collection efficiency on a sphere with experimental data. Droplet trajectory calculations were then conducted on a NACA0012 rotor in hover
Buchen, Philipp, Sotomayor-Zakharov, Denis, Knop, Inken
A Three-Layer Model for Ice Crystal Icing in Aircraft Engines2023-01-148106/15/2023
This paper presents the current state of a three-layer surface icing model for ice crystal icing risk assessment in aircraft engines, being developed jointly by Ansys and Honeywell to account for possible heat transfer from inside an engine into the flow path where ice accretion occurs. The bottom layer of the proposed model represents a thin metal sheet as a substrate surface to conductively transfer heat from an engine-internal reservoir to the ice layer. The middle layer is accretion ice with a porous structure able to hold a certain amount of liquid water. A shallow water film layer on the top receives impinged ice crystals. A mass and energy balance calculation for the film determines ice accretion rate. Water wicking and recovery is introduced to transfer liquid water between film layer and porous ice accretion layer. Numerical tests have been conducted to verify new model behaviors like substrate surface heat absorption into the accretion layer in the form of meltwater, water
Zhang, Yue, Narayanasamy, Karthik, Sandel, Wolfgang, Nilamdeen, Shezad, Ozcer, Isik
Airborne Platform for Ice-Accretion and Coatings Tests with Ultrasonic Readings (PICTUR)2023-01-143106/15/2023
Hazardous atmospheric icing conditions occur at sub-zero temperatures when droplets come into contact with aircraft and freeze, degrading aircraft performance and handling, introducing bias into some of the vital measurements needed for aircraft operation (e.g., air speed). Nonetheless, government regulations allow certified aircraft to fly in limited icing environments. The capability of aircraft sensors to identify all hazardous icing environments is limited. To address the current challenges in aircraft icing detection and protection, we present herein a platform designed for in-flight testing of ice protection solutions and icing detection technologies. The recently developed Platform for Ice-accretion and Coatings Tests with Ultrasonic Readings (PICTUR) was evaluated using CFD simulations and installed on the National Research Council Canada (NRC) Convair-580 aircraft that has flown in icing conditions over North East USA, during February 2022. This aircraft is a flying laboratory
Nichman, Leonid, Fuleki, Dan, Song, Naiheng, Benmeddour, Ali, Wolde, Mengistu, Orchard, David, Matida, Edgar, Bala, Kenny, Sun, Zhigang, Bliankinshtein, Natalia, Ranjbar, Keyvan, DiVito, Stephanie
Snow Effects on the NGCTR Nacelle for Relevant Certification Conditions2023-01-137306/15/2023
This paper is focused on the numerical analysis of the impingement and water catch rate of snow particles on the engine air intake of the Next Generation Civil Tilt Rotor (NGCTR). This NGCTR is developed by Leonardo Helicopters. The collection efficiency and water catch rate for the intake geometry are obtained for the test cases that have been defined for the relevant snow conditions. These conditions are related to the flight envelope of the NGCTR, existing EASA/FAA certification specifications, and the snow characterization. The analyses have been performed for the baseline air intake geometry. A range of particle diameters has been simulated with a particle density equal to the density of ice and with a particle drag relation that disregards the particle shape. Based on the results for the water catch rate on the basic nacelle configuration in snow conditions it is concluded that the ‘cheeks’ of the duct are more susceptible to impingement of larger snow crystals (>75 μm), whereas
Kool, Nina, Van der Weide, Edwin, Spek, Ferdinand, van der Ven, Harmen, van 't Hoff, Stefan
Multi-step Ice Accretion by Immersed Boundaries2023-01-148406/15/2023
The paper describes a tools’ suite able of analyzing numerically 3D ice-accretion problems of aeronautical interest. The methodology consists of linking different modules each of them performing a specific function inside the ice-simulation chain. It has been specifically designed from the beginning with multi-step capability in mind. Such a feature plays a key role when studying the dynamic evolution of the icing process. Indeed, the latter has the character of a multi-physic and time-dependent phenomenon which foresees a strong interaction of the air- and water fields with the wall thermodynamics. Our multi-layer approach assumes that the physical problem can be discretized by a series of pseudo-steady conditions. The simulation process starts with the automatic generation of a Cartesian three-dimensional mesh which represents the input for the immersed boundary (IB) RANS solver. Once obtained, the air-phase is used by the Eulerian tool to solve the transport of the water-phase on
de Rosa, Donato, Capizzano, Francesco, Cinquegrana, Davide
Development of an Altitude Evaporation Model for Icing Tunnel Control2023-01-142506/15/2023
In 2017 the National Research Council of Canada developed an evaporation model for controlling engine icing tunnels in real time. The model included simplifications to allow it to update the control system once per second, including the assumption of sea level pressure in some calculations. Recently the engine icing system was required in an altitude facility requiring operation down to static temperatures of -40°C, and up to an altitude of 9.1 km (30 kft) or 30 kPa. To accommodate the larger temperature and pressure range the model was modified by removing the assumption of sea level operation and expanding the temperature range. In addition, due to the higher concentration of water vapor that can be held by the atmosphere at lower pressures, the significance of the effect of humidity on the air properties and the effect on the model was investigated. The effect of humidity on the density, specific heat, viscosity, thermal conductivity and Prandtl number of air compared to assuming
Davison, Craig
A Comprehensive Numerical Model for Numerical Simulation of Ice Accretion and Electro-Thermal Ice Protection System in Anti-icing and De-icing Mode, with an Ice Shedding Analysis2023-01-146306/15/2023
This work presents a comprehensive numerical model for ice accretion and Ice Protection System (IPS) simulation over a 2D component, such as an airfoil. The model is based on the Myers model for ice accretion and extended to include the possibility of a heated substratum. Six different icing conditions that can occur during in-flight ice accretion with an Electro-Thermal Ice Protection System (ETIPS) activated are identified. Each condition presents one or more layers with a different water phase. Depending on the heat fluxes, there could be only liquid water, ice, or a combination of both on the substratum. The possible layers are the ice layer on the substratum, the running liquid film over ice or substratum, and the static liquid film between ice and substratum caused by ice melting. The last layer, which is always present, is the substratum. The physical model that describes the evolution of these layers is based on the Stefan problem. For each layer, one heat equation is solved
Gallia, Mariachiara, Rausa, Andrea, Martuffo, Alessandro, Guardone, Alberto
Snow Particle Characterization. Part B: Morphology Dependent Study of Snow Crystal 3D Properties Using a Convolutional Neural Network (CNN)2023-01-148606/15/2023
This study presents the results of the ICE GENESIS 2021 Swiss Jura Flight Campaign in a way that is readily usable for ice accretion modelling and aims at improving the description of snow particles for model inputs. 2D images from two OAP probes, namely 2D-S and PIP, have been used to extract 3D shape parameters in the oblate spheroid assumption, as there are the diameter of the sphere of equivalent volume as ellipsoid, sphericity, orthogonal sphericity, and an estimation of bulk density of individual ice crystals through a mass-geometry parametrization. Innovative shape recognition algorithm, based on Convolutional Neural Network, has been used to identify ice crystal shapes based on these images and produce shape-specific mass particle size distributions to describe cloud ice content quantitatively in details. 3D shape descriptors and bulk density have been extracted for all the data collected in cloud environments described in the regulation as icing conditions. They are presented
JAFFEUX, Louis, Coutris, Pierre, Schwarzenboeck, Alfons, Dezitter, Fabien
Impingement Analysis on Nacelle Inlet, Multibody Airfoil, and Swept Tail Cases under SLD Conditions2023-01-137606/15/2023
This paper presents impingement analysis on a nacelle inlet, multibody airfoil, and swept tail under Supercooled Large Droplet (SLD) conditions in icing tunnels. Impingement and collection efficiency calculations are crucial for ice shape and protection analyses. The aerospace icing community selected three cases for simulation, focusing on SLD conditions, which require specific mathematical models for accurate representation. The present authors used a Reynolds-averaged Navier-Stokes computational fluid dynamics (CFD) tool to evaluate pressure coefficients and collection efficiency, comparing them with experimental data. CFD simulations incorporated fully turbulent flow using various turbulence models and Eulerian droplet transport, considering experimental droplet distribution. The results showed acceptable deviations despite SLD simulation challenges and experimental data problems. A secondary conclusion suggests simplifying a 27-bin distribution to a 10-bin distribution to take
Da Silva, Guilherme, Pio, Diogo, Rafael, Caio, Villela, Pedro, Rezende, Sabrina, Teixeira Da Silva, Jayme
A CIRA 3D Ice Accretion Code for Multiple Cloud Conditions Simulations2023-01-146106/15/2023
This work presents the implementation and validation efforts of a 3D ice accretion solver for aeronautical applications, MESS3D, based on the advanced Messinger model. The solver is designed to deal with both liquid phase and ice crystal cloud conditions. In order to extend the Messinger model to 3D applications, an algorithm for the water run-back distribution on the surface was implemented, in place of an air flow stagnation line search algorithm, which is straightforward in 2D applications, but more complicated in 3D. The developed algorithm aims to distribute the run-back water in directions determined by air pressure gradients or shear forces. The data structure chosen for MESS3D allows high flexibility since it can manage the necessary input solutions on surface grids coming from both structured and unstructured solvers, regardless the number of edges per surface cells. The aim of the work is to present a validation of the model by examining the robustness of the solutions when
Cinquegrana, Davide, D'Aniello, Francesco, de Rosa, Donato, Carozza, Antonio, Catalano, Pietro, Mingione, Giuseppe
Design, Characterization and Initial Testing of a Vertical Stabilizer Common Research Model for Aircraft Ground Icing Testing2023-01-143906/15/2023
Under contract to Transport Canada (TC) and with joint funding support from the Federal Aviation Administration (FAA), a vertical stabilizer common research model (VS-CRM) has been designed and built by the National Research Council of Canada (NRC). This model is a realistic, scaled representation of modern vertical stabilizer designs without being specific to a particular aircraft. The model was installed and tested in the NRC 3 m × 6 m Icing Wind Tunnel in late 2021/early 2022. Testing was led by APS Aviation Inc., with support from NRC and NASA, in order to observe the anti-icing fluids flow-off behavior with and without freezing or frozen precipitation during simulated take-off velocity profiles. The model dry-air aerodynamic properties were characterized using flow visualization tufts and boundary layer rakes. Using this data, a target baseline configuration was selected with a yaw angle equal to 0° and rudder deflection angle equal to -10°. Testing with fluids and precipitation
Clark, Catherine, Ruggi, Marco
Reduced-Order modeling of Icing CFD data for Uncertainty Quantification of Icing Wind tunnel Experiments2023-01-147206/15/2023
During icing wind tunnel experiments, the calibration process of the spray nozzle and aerothermal systems introduces experimental uncertainty that can potentially compromise the reliability of the test results. Therefore, performing sensitivity analysis (SA) or uncertainty quantification (UQ) studies is not only essential to determine the influence of uncertainties on the ice shape and aerodynamic performance but also crucial to identify the most significant icing parameter uncertainty. However, given the wide range of icing envelopes, it is not practical to conduct SA and UQ by experimental method because a lot of evaluations are required for SA and UQ study. In this study, we addressed these challenges by using a deep learning-based reduced-order modeling technique. First, a dataset covering a wide range of icing envelopes was obtained through icing CFD simulations, and then reduced-order modeling was trained on this dataset to build a model that can efficiently predict the ice shape
Kang, Yu-Eop, Yee, Kwanjung
Large-Eddy Simulation of a NACA23012 Airfoil under Clean and Iced Conditions2023-01-148306/15/2023
Predicting the aerodynamic performance of an aircraft in icing conditions is critical as failures in an aircraft’s ice protection system can compromise flight safety. Aerodynamic effects of icing have typically relied on RANS modeling, which usually struggles to predict stall behavior, including those induced by surface roughness. Encouraged by recent studies using LES that demonstrate the ability to predict stall characteristics on full aircraft with smooth wings at an affordable cost [1], this study seeks to apply this methodology to icing conditions. Measurements of lift, drag, and pitching moments of a NACA23012 airfoil under clean and iced conditions are collected at Re = 1.8M. Using laser scanned, detailed representations of the icing geometries, LES calculations are conducted to compare integrated loads against experimental measurements in both clean and iced conditions at various angles of attack through the onset of stall [2]. This study will explore several critical ice
Bornhoft, Brett, Jain, Suhas, Goc, Konrad, Bose, Sanjeeb, Moin, Parviz
Liquid Water Detection Algorithm for the Magnetostrictive Ice Detector2023-01-143006/15/2023
For nearly a century, ice build-up on aircraft surfaces has presented a safety concern for the aviation industry. Pilot observations of visible moisture and temperature has been used a primary means to detect conditions conducive to ice accretion on aircraft critical surfaces. To help relieve flight crew workload and improve aircraft safety, various ice detection systems have been developed. Some ice detection systems have been successfully certified as the primary means of detecting ice, negating the need for the flight crew to actively monitor for icing conditions. To achieve certification as a Primary ice detection system requires detailed substantiation of ice detector performance over the full range of icing conditions and aircraft flight conditions. Some notable events in the aviation industry have highlighted certain areas of the icing envelope that require special attention. Following the CRJ accident in Fredericton, New Brunswick, Canada, in December 1997, industry interest
Jackson, Darren, Anderson, Kaare, Heuer, Weston
Roughness Parameter Optimization of the McClain Model in GlennICE2023-01-146806/15/2023
Aircraft icing remains a significant threat to aviation safety. Software that predicts the impingement and ice accretion on full aircraft geometries and aircraft components are in demand and NASA Glenn is committed to produce software that meets this need. One of the key parameters affecting an accurate prediction of iced geometry is the effect of ice roughness on the heat transfer coefficient. While many efforts have been made to implement the roughness in the flow solver, this report takes a correlation for roughness height distribution that is based on experimental measurements and demonstrates how to relate those measurements to an augmentation to the heat transfer coefficient provided by the flow solution. The outcome of this effort was the callibration of defaults for user supplied parameters to this correlation through comparison with 95 large glaze conditions from experiment by adjusting user-supplied parameters in the roughness augmentation equation.
Wright, William, Rigby, David, Ozoroski, Thomas
3D Immersed Boundary Methods for the Calculations of Droplet Trajectories towards Icing Application2023-01-145806/15/2023
The in-flight ice accretion simulations are typically performed using a quasi-steady formulation through a multi-step approach. As the ice grows, the geometry changes, and an adaptation of the fluid volume mesh used by the airflow and droplet-trajectory solver is required. Re-meshing or mesh deformation are generally employed to do that. The geometries formed are often complex ice shapes increasing the difficulty of the re-meshing process, especially in three-dimensional simulations. Consequently, difficulties are encountered when trying to automate the process. Contrary to the usual body-fitted mesh approach, the use of immersed boundary methods (IBMs) allows solving, or greatly reducing, this problem by removing the mesh update, facilitating the global automation of the simulation. In the following paper, an approach to perform the airflow and droplet trajectory calculations for three-dimensional simulations is presented. This framework utilizes only immersed boundary methods. In
Elices Paz, Pablo, Radenac, Emmanuel, Péron, Stéphanie, Blanchard, Ghislain, Laurendeau, Eric, Villedieu, Philippe
Optical Temperature Sensor for Thermodynamic Measurement of Icing Dynamics2023-01-142206/15/2023
A fundamental understanding of the icing process for aircraft requires a more thorough analysis of the thermodynamics of supercooled droplet impingement. To better study such thermodynamic processes, a novel temperature sensor that functions within supercooled water and ice crystals was developed. The temperature sensor is non-intrusive and provides temperature and phase change information for both liquid water and solid ice. The temperature sensor is an optical sensor based on the luminophore pyranine. The use of pyranine allows for the measurement of spatially and temporally resolved temperature fields for icing applications. The sensitivity of the sensor is -9.2±0.1%/K for temperature measurement in the solid phase and 0.8±0.1%/K for the liquid phase. The performance of the sensor was demonstrated through a calibration process using spectral analysis, the observation of the melting process of a rectangular prism created from the luminescent ice, and the study of the temperature
Gonzales, Joseph, Yamazaki, Masafumi, Sakaue, Hirotaka
Ice Crystal Accretion Tool (ICAT) capabilities on heated NACA0012 Airfoil2023-01-138806/15/2023
The present paper showcases the predicting ability of an in-house 2D/ Quasi-3D steady state Ice Crystal Accretion Tool (ICAT) applicable for both heated and un-heated surfaces. The previously existing code for unheated surfaces, has been extended to heated scenarios with the inclusion of: 1) coupling with solid conduction model 2) inclusion of advanced models for crystal melting, water film modeling, sticking and erosion. The results obtained from ICAT are verified against the experimental results of heated NACA0012 airfoil, conducted in the icing wind tunnel of TU Braunschweig as part of MUSIC-haic project. ICAT predictions are found to be well in agreement with the ICI physics, which is proven with the various parameters addressed in this paper, such as tunnel temperature, ice crystal temperature, inlet melt ratio, heating power, etc.
Roychowdhury, Somasree, Poornima, Rajani, Bokade, Vilas, Jebauer, Steffen, Vanacore, Paolo, Malik, Yasir A.
Optical Ice Detector Lite: Initial Flight Test Results2023-01-142706/15/2023
In response to safety regulations regarding aircraft icing, Collins Aerospace has developed and tested a new generation of optical ice detectors (OID Lite) intended to discriminate among icing conditions described by Appendix C and Appendix O of 14 CFR Part 25 and Appendix D of Part 33. The OID Lite is a flush-mounted, short-range, polarimetric optical sensor that samples the airstream up to two meters beyond the skin of the aircraft. The intensity and polarization of the backscatter light correlate with bulk properties of the cloud, such as cloud density and phase. Drizzle-sized droplets, mixed within a small droplet cloud, appear as scintillation spikes in the lidar signal when it is processed pulse-by-pulse. Scintillation in the backscatter (in combination with the outside air temperature monitored by another probe) signals the presence of supercooled large droplets (SLD) within the cloud—a capability incorporated into the OID Lite to meet the requirements of Appendix O. Recent
Ray, Mark, Anderson, Kaare, Ramthun, Kent
Could Superhydrophobic Surfaces be a Realistic Solution for Running-Wet Areas?2023-01-144606/15/2023
Thermal ice protection systems (IPS) are used extensively in aeronautics. They are tailored according to the aircraft characteristics or flight envelope and can be used in different modes, anti-icing to avoid ice accretion or de-icing to remove the ice once accreted. A relevant issue by this application is the runback icing, caused by the downstream flow of melted or running water to unprotected areas, where activation is not possible in terms of energy consumption. Passive systems are being explored to complement or replace active systems, although, up to now, solutions have not been reported with the required performance for real-life applications. One of the most commonly reported anti-icing strategy relays on superhydrophobicity, i.e., it is based on the water roll-off capacity of Cassie-Baxter superhydrophobic surfaces (CB-SHP). Precisely, running wet phenomena, where liquid water is flowing on the surface, could be an appropiate application field for this type of materials
Mora, Julio, García, Paloma, Carreño, Francisco, Montes, Laura, López-Santos, Carmen, Rico, Victor, Borras, Ana, Redondo, Francisco, González-Elipe, Agustín R., Agüero, Alina
Integration and Testing of HeatCoat Carbon-Nanotube Ice Protection System on an Unmanned Aerial Vehicle2023-01-137506/15/2023
The process for certifying an existing aircraft for flight into known icing is well defined and must follow specific guidelines and meet specific milestones. As UAVs are still a relatively recent development, guidelines for icing flight certification of a UAV have not yet been developed by the FAA, and no UAVs have yet been certified for FIKI under the FAA. As part of a research program, engineers at the Battelle Memorial Institute in Columbus, OH USA worked with partners to integrate its ice protection system, HeatCoatTM, onto an existing UAV platform as a retrofit with the ultimate goal of flying in icing conditions. This research program was funded by the US Government with intent to integrate HeatCoat on the TigerShark-XP UAV. The integration on the TigerShark was demonstrated to present challenges specific to the nature of this UAV that had to be overcome. This research program required simulation of icing accretion using multiple software packages, ground based icing tunnel
Yugulis, Kevin, Chase, David, Kenney, Brian
In Flight Ice Shape Prediction with Data Fit Surrogate Models2023-01-148006/15/2023
Accurate simulation of icing is important for the assessment of several potential icing scenarios and complex icing regulations. However, performing all possible icing scenarios is a demanding process in terms of computational cost, especially when modification of the geometry due to ice accretion is required. Additionally, aircraft icing safety assessment necessitates an evaluation of the accumulated ice. Thus, numerical representation of the non-linear and complex geometries is essential for the parametrization of this ice. Indeed, surrogate models have the capability of predicting these complex, non-linear shapes. For this purpose, a method for ice accretion prediction on a selected airfoil, NACA 22112, is proposed in this study with different surrogate models that will later be used for fast prediction in 6DOF simulations to directly evaluate its effects on aerodynamic performance during flight. The required datasets in order to train for clean and iced airfoils are based on
Akbal, Omer, Ayan, Erdem, Murat, Canibek, Ozgen, Serkan
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