NASA Icing Update

National Aeronautics and Space Administration

NASA Icing Update

Andy Broeren Icing Branch NASA Glenn Research Center

SAE AC-9C COMMITTEE MEETING

In-Person in San Diego, CA and Webex April 4, 2022 www.nasa.gov

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Contents

• NASA Icing Research Tunnel Update – Laura King-Steen and Emily Timko • Ice Crystal Icing Experimental Research – Tadas Bartkus • Hybrid and Full Chord CRM65 Ice Accretion Testing – Andy Broeren and Sam Lee • Bimodal Cloud Ice Accretion Testing – Paul Tsao • GlennICE Software Development Update – Christopher Porter www.nasa.gov

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Icing Research Tunnel: Status Update

IRT Cloud Cals since 2019 Full Cal:

• 2019: Full Calibration

– Cal Report now available on ntrs.nasa.gov: NASA TM-20205009045, by Timko, et. al – Uniformity (Grid) – LWC (Multi-wire) • Icing Blade confirmed low-impingement-rate conditions – Drop Size (CDP, OAP-230X, OAP-230Y)

• Jan & Mar 2020: 2 Check Cals

– Uniformity & LWC

 Mar 2020: IRT shut down for COVID

 Jan 2021: IRT restart efforts began, • Test section size: 6 ft. x 9 ft. (1.8 m x 2.7 m)

included a few large maintenance items

• Calibrated test section airspeed: 50 –300 kts

 Aug 2021: IRT fan restart

• Air temperature: -35ºC static to +15ºC total • Two types of spray nozzles:

• Sept 2021: IRT Restart Checks

• Standards = higher water flow rate – Uniformity, LWC, and Drop Sizing • Mod1 = lower water flow rate • Icing Blade confirmed low-impingement-rate conditions • Calibrated MVD range: 14 – 270 μm

• Jan & Mar 2022: 2 Check Cals • Calibrated LWC range: 0.17 –4.0 g/m (function of

airspeed) – Uniformity, LWC, and Drop Sizing www.nasa.gov

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Uniformity Results—Overall

• Center Regions looked OK—central 2x2 ft was consistently within 10% of 2019

– Some differences were seen in outer regions

• Example Cases shown here: -3 Mod1 Center 12 Average Thickness = 405 x10 in.

– Standards Baseline: 150 kts, MVD=20.0 μ m , LWC=1.37 g/m

Off-white indicates 0-5% change, – Mod1 Baseline: 150 kts, MVD=21.5 μ m , LWC=0.85 g/m light red/blue is 5-10%, darker red/blue is 10-15%

Difference Map, 9/10/21 Run #2

Normalized Unif: Standard Baseline, Normalized Unif: Mod1 Baseline,

vs. Mod1 baseline on 5/23/19, Run #2

9/10/21, Run #1

9/10/21, Run #2

63 63 57 57 51 51 45 45 39 39 39 33 33 33 27 27 21 21 21 Distance Above Floor (in.)

Distance Above Floor (in.) Distance Above Floor (in.)

15 15 9 9 9 Thickness / Ctr12Avg Thickness / Ctr12Avg 3 3 -36 -30 -24 -18 -12 -6 0 6 12 18 24 30 36 -36 -30 -24 -18 -12 -6 0 6 12 18 24 30 36 -36 -30 -24 -18 -12 -6 0 6 12 18 24 30 36 Distance from Centerline (in.)

-3 (x10 in.)

Distance from Centerline (in.) Distance From Centerline (facing Downstream) (in.)

-100--80 -80--60 -60--40 -40--20 0.50-0.60 0.60-0.70 0.70-0.80 0.80-0.90 0.90-1.00 0.50-0.60 0.60-0.70 0.70-0.80 0.80-0.90 0.90-1.00 www.nasa.gov 4 -20-0 0-20 20-40 40-60 1.00-1.10 1.10-1.20 1.20-1.30 1.30-1.40 1.40-1.50 1.00-1.10 1.10-1.20 1.20-1.30 1.30-1.40 1.40-1.50

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IRT Liquid Water Content Results

• In 2021 & 2022, the LWC for most conditions in our operating envelope fit the IRT’s

stated repeatability values

– ±10% for normal (App C) operating conditions and ±20% for SLD conditions

• We do have some small regions of the operating envelopes that we’re keeping an eye on—

we have been and will continue to have conversations with customers about any test points

they may have in these regions as the need arises

Mod1 Nozzles Standard Nozzles

Mod1, SLD

2.5 5.0 1.6 1:1 Line 1:1 Line 1:1 +/- 10% +/- 10% +/- 10% May 2019 May 2019 +/- 20% 2.0 4.0 Jan 2020 Jan 2020 ) ) May 2019 1.2 3 3 ) Mar 2020, chk cal Mar 2020, chk cal Jan 2020 Sept 2021 Sept 2021 Sept 2021 1.5 3.0 Jan 2022 Jan 2022 0.8 1.0 2.0 LWC, Measured (g/m LWC, Measured (g/m 0.4 LWC, Measured (g/m 0.5 1.0 0.0 0.0 0.0 0.0 0.5 1.0 1.5 2.0 2.5 0.0 1.0 2.0 3.0 4.0 5.0 0.0 0.4 0.8 1.2 1.6 3 3 3 www.nasa.gov 5 2019 LWC Curve Fit (g/m ) LWC, Calculated (g/m ) 2019 LWC Curve Fit (g/m )

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Ice Crystal Icing Experimental Research

• Generate a set of ice accretion data on a 3D test article to validate GlennICE ice accretion models • Conduct ice crystal icing and supercooled water icing tests in the NASA Icing Research Tunnel (IRT) • Utilize Simulated Inter-compressor Duct Research Model (SIDRM) • Representative of an inter-compressor duct and strut region of a turbofan engine (heated curved surface with a strut) • 17 days of icing tests with SIDRM test article (Feb 16 - 25 and April 11 – 22) • 13 day of Ice Crystal Cloud Characterization (Jan 31 – Feb 13 and March 14 – 16) www.nasa.gov

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Ice Crystal Cloud Characterization at IRT

• Ice crystal generation is not well characterized at IRT • Ice crystal cloud envelope limited to colder, slower, and smaller diameter.

• Well characterized cloud needed to properly model resulting icing data • Objective: Characterize IC cloud using following instrument suite Instrument Measurement Multiwire Melt ratio & recirculation Isokinetic Probe Total water content & recirculation Rearward Facing Probe Air temperature and humidity Ice Crystal Particle Imager (Artium) Particle size distribution TAT probe (Rosemount) Air temperature Flow Ice Detector (UTC Aerospace) Glaciation (liquid presence) Test Section Background Hum Test section humidity Various probes installed in the NASA IRT test section Spray Bar Background Hum Upstream humidity during IC cloud characterization tests in Feb 2022 Light Extinction Probe Recirculation www.nasa.gov

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SIDRM Tests and Objectives

Test type and Objectives: 1. Perform aero-thermal characterization of SIDRM test article 2. Generate supercooled water ice accretion data for various conditions 3. Generate ice-crystal icing data for various conditions utilizing a conducting (heated) surface 4. Investigate transient heat conduction during ice crystal icing Key Measurements: Flow • Laser scanned 3D geometry of ice accretion • 1D and 2D accretion profiles extracted from video • Ice mass (and density) • Surface temperature Ice accretion on the SIDRM test article due to supercooled water • Surface heat flux icing (left) and ice crystal icing (right) during tests in Feb 2022 www.nasa.gov

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Hybrid and Full Chord CRM65 IRT Testing

• In January 2022, three week of IRT testing were completed with

the hybrid and full-chord versions of the CRM65 wing sections.

• This completed the work begun in 2020 to confirm the hybrid

model design approach and extend the ice accretion database

for large-drop conditions. See AIAA Papers 2021-2678 and

2021-2679.

Clean Full Chord

Hybrid Model

Full Chord Model

Hybrid z (in) -5 -10 -5 0 5 10 15 20 x' (in) www.nasa.gov

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Bimodal Ice Accretion on CRM65 Midspan Models

Hybrid and Full-Chord

OBJECTIVE: • Develop database of ice shapes for bimodal icing conditions on the CRM65 hybrid and full-chord midspan wing section models.

• Establish a correlation between hybrid and full chord model ice shapes.

CHALLENGES: • Obtain large ice scallop at high velocity conditions without shedding.

• Models were able to run at 230 and 180 knots at high lift Large ice scallop on hybrid mid-span model in IRT, TH3275 to compare with several bimodal cloud conditions.

RESULTS: • Collected photographs, digital ice shape scans, and ice mass measurements for each spray.

• Preliminary full-chord results show good correlation with hybrid model results from December 2021 test entry.

MCCS ice profile and ice mass comparison for CURRENT STATUS: TH3275 (603g) vs TJ3454 (629g) • A paper to be presented in AIAA 2022 Aviation Forum to show ice shape comparisons on hybrid and full-chord models with bimodal Large ice scallop on full-chord mid- cloud at different icing conditions span model in IRT, TJ3454 www.nasa.gov

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GlennICE Development

0.1 0.2 1.0 1.1 1.2 2.0 2.1 2.2 3.0 3.1 3.2 4.0 4.1 4.2 5.0 5.1 5.2 6.0 6.1 6.2 Version 2/20 6/20 10/20 2/21 6/21 10/21 2/22 6/22 10/22 2/23 6/23 10/23 2/24 6/24 10/24 2/25 6/25 10/25 2/26 6/26 Timeline External Icing Rotating Icing (Super Cooled) Internal Icing (Ice Crystal) • Quasi-3D (LEWICE3D) → Full 3D • Introduce rotating reference frames • Introduce ice crystals and related (GlennICE) (Engine Fan and Propellors). physics • Utilize modern programming • Handle periodic boundary • Address multiphase runback and practices and capabilities. conditions/mixing planes.

icing.

Version 2.2 Planned Additions Version 2.1 Improvements • Multiple node, distributed memory • Introduce rotating reference frames.

• Improved robustness of feature finding. parallelization.

• Single node, shared memory parallelization. • Significantly improved release point initialization efficiency.

• Removed requirement to be provided volume/surface nodal connectivity.

GlennICE is currently not available on NASA’s Software Store.

www.nasa.gov

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External Icing Simulations with GlennICE

• Implemented a two-part adaptive trajectory refinement scheme:

• Feature finding (limit misses)

• Collection based adaptive refinement (reduce hits that don’t

improve the prediction of collection efficiency)

• Implemented a fully three-dimensional ice growth formulation:

• Runback is an algebraic model based on shear

• Heat transfer is augmented as a function of local roughness

computed using McClain’s method.

• Ice growth is a prismatoid extrusion method with node based

smoothing .

A full 3D GlennICE simulation of an ice accretion due to a 15 μm cloud on the Seed plane of released trajectories and the resulting computational prediction of collection TTBW. Insets depict the accretion on the engine inlet, with the line plot efficiency (beta) utilizing GlennICE on the SEA Multi-Element Probe, an experimental including a comparison to the legacy quasi-3D icing software, LEWICE3D.

device that measures total water content.

McClain, Stephen T., et al. "A Model for Ice Accretion Roughness Evolution and Spatial Variations." AIAA AVIATION 2021 FORUM. 2021.

www.nasa.gov Porter, Christopher E., and David L. Rigby. "Three Dimensional Surface Redefinition Method for Computational Ice Accretion Solvers." AIAA AVIATION 2020 FORUM. 2020.

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Rotating Reference Frame in GlennICE

The next major feature enhancement to GlennICE is the ability to

handle rotating reference frames.

This addition will enable GlennICE to perform supercooled liquid

icing analysis on rotating geometries such as propellers and fans.

A propeller test geometry that aligns with the AAM effort

sponsored by RVLT will be utilized to benchmark the addition of

rotating reference frames.

Schematic of the Advanced Air Mobility Rotor Test Stand.

Addition of the Centrifugal and Coriolis Forces to Trajectory Integrator A proposed defeatured computational geometry to demonstrate the capability of GlennICE to handle rotating reference frames.

Non-Rotating Frame of Reference Rotating Frame of Reference www.nasa.gov