Document
National Aeronautics and Space Administration Icing Physics Studies Using the 3D SIDRM Test Article:
Aerodynamic and Supercooled Liquid Icing Analysis
Tadas P. Bartkus – Ohio Aerospace Institute
Sam Lee – HX5
Eric A. Stewart – Naval Air Warfare Center Aircraft Division
SAE International Conference on Icing of Aircraft, Engines, and Structures June 20 – 22, 2023 This material is a work of the U.S. Government and is not subject to copyright protection in the United States www.nasa.gov
Introduction – Why Study Engine Icing
• Numerous events of power - loss and engine damage since the 1990’s (Bravin, 2019)
• Engine icing (ice crystal icing) studied at NASA (and elsewhere)
• From full scale engine tests to component level fundamental icing physics studies
• Goal : Gather data to develop and validate computational icing tools to predictively assess the
onset and growth of ice in current and future engines during flight, to aid certification
National Aeronautics and Space Administration 2 21.7 in
SIDRM
Testing General Details
schematic
71.8 in 62.6 in Flow
• Conducted icing tests in the NASA Icing Research Tunnel (IRT)
• Conducted in early 2022 • Utilized Simulated Inter - compressor Duct Research Model (SIDRM) • 3D geometrical features of an inter - compressor duct and strut region of a turbofan engine (curved surface with a strut) • 17 days of testing
SIDRM
profile
• Aerothermal characterization
view
• Supercooled liquid icing tests • Ice crystal icing tests
• Testing primary goal : Generate a set of ice accretions on a 3D
test article to provide validation data for engine icing simulation
Generic
tools like GlennICE
engine
schematic
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SIDRM Built - In Instrumentation
4” NACA0012 Instrumented Strut Strut P206 P217 P216 P215 P210 P211 P212 P208 P207 P213 P214 P209
• 64 Pressure taps
· · · · · · · · · · · · · P218
• 43 Thermocouples
ST2 T407 ST1 x X
• 11 Heat flux gauges
ST2 · · ST1 T401 T301 · · · · · · · · · · · · ·
• Imbedded internally in aluminum main body
T303 T302 T306 T311 T312 T313 T314 T315 T304 T305 T310 z Z · · T207 T201
• 6 Independently controlled heater zones
Leading T307 Edge
• Beneath main body skin
P118 Flow · · · · · · · · · · · · · P113 P116 P115 P112 P114 P117 P107 P108 P109 P110 P111 P106
• Heaters are symmetric on both sides
View of TCs, pressure taps and heater zones (shaded areas) National Aeronautics and Space Administration
Aerothermal Tests
Objective:
• Performed to characterize flow around unique geometry
• Compare against simulation predictions
Measurements:
• Pressure taps (comparisons with CFD shown)
• Thermocouples
Test Conditions:
AoA (°) 0 0 0 0 0 1 2 3 4 4 4 4 4
U (knots) 50 100 150 200 230 150 150 150 50 100 150 200 230
National Aeronautics and Space Administration 5 AoA = 0°, U = 150 knots -3.0 Lower Instr.
Aerodynamic Tests
-2.5 Lower Non-Instr.
Upper Instr.
-2.0 Upper Non-Instr.
• Good agreement btw sim and exp
CFD -1.5
• Tap measurements
-1.0
• 4 curves (upper/lower, both sides)
-0.5 °
• Lay on top of each other at AoA = 0
Pressure Coefficient 0.0
• Flow separation beyond z/c = - 0.8
0.5
• Ansys Fluent
1.0 -1.0 -0.8 -0.6 -0.4 -0.2 0.0
• Simulated SIDRM inside tunnel with
z/c
no slip at SIDRM walls
AoA (°) 0 0 0 0 0 1 2 3 4 4 4 4 4 U (knots) 50 100 150 200 230 150 150 150 50 100 150 200 230 Flow National Aeronautics and Space Administration 6 z/c - 0.90 - 0.80 AoA = 4°, Lower Row Taps -4.0 U = 50 knots -3.5 U = 100 knots
Exp
-3.0 U = 150 knots
Aerodynamic Tests
U = 200 knots -2.5 U = 230 knots -2.0
• Good agreement btw sim and exp
-1.5 -1.0
• Both capture suction spike near LE
-0.5 0.0 Pressure Coefficient
• Both capture Cp spread with
0.5 1.0
increasing airspeed at z/c = - 0.4
1.5
(Reynolds number effect)
-1.0 -0.8 -0.6 -0.4 -0.2 0.0 z/c
• Negative lift produced in aft half at
-2.4 °
AoA = 4
-2.2
Sim
-2.0 -1.8 Suction -0.08 -0.04 Neg Lift Pos Lift AoA (°) 0 0 0 0 0 1 2 3 4 4 4 4 4 Suction U (knots) 50 100 150 200 230 150 150 150 50 100 150 200 230 Pressure Coefficient - - - - - National Aeronautics and Space Administration 7 z/c
Supercooled Liquid Icing
Measurements:
Parameters that impacted: • Ice geometry (3D scanner)
• Ice mass (cut and weigh)
1. Icing size (and mass)
• Surface TCs
2. Location (icing extent)
• Photo/video
3. Characteristics
4. Surface temperature
8 in Parameter Sweeps conducted:
• 3 MVD sweeps
The gray semi-circle is 10 in the SIDRM test article
• 1 Total air temperature sweep
for this 4° AoA test run.
An xy -plane cut made at
• 1 AoA sweep
z = -0.5 inches from the SIDRM leading edge.
• 2 Accretion time sweeps
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Supercooled Liquid Icing – Size: MVD
Centerline cut
• Larger MVD ➔ larger ice accretion
• Larger MVD ➔ more ballistic
• Larger MVD ➔ greater collection eff.
Target Test Conditions Ice Accretion Measurements 1 Col 2 Col 3 Col 4 Col 5 Col 6 Col 7 Col 8 Col 9 Col 10 Accretion Both Struts Main Body LE ID Time T U AoA MVD LWC Ice Mass Ice Mass Ice Vol.
3 3 ) (min) (°C) (knots) (°) (μm) (g/m ) (g) (g) (cm ) 513 10 -17 150 0 15 0.45 66 172 56.3 514 10 -17 150 0 18 0.45 70 221 62.3 518 10 -17 150 0 30 0.45 79 407 78.8 515 10 -17 150 0 50 0.45 79 548 87.1 516 10 -17 150 0 90 0.45 83 781 93.7 National Aeronautics and Space Administration 9
Supercooled Liquid Icing – Size: T
• Colder T ➔ larger ice accretion
• Colder T ➔ less feather shedding
• Colder T ➔ Stronger ice cohesion,
fewer large feathers experiencing
larger drag forces
Pressure Suction Side Side Target Test Conditions Ice Accretion Measurements Col 2 Col 3 Col 4 Col 5 Col 6 Col 7 Col 8 Col 9 Col 10 Accretion Both Struts Main Body LE D Time T U AoA MVD LWC Ice Mass Ice Mass Ice Vol.
3 3 (min) (°C) (knots) (°) (μm) (g/m ) (g) (g) (cm ) Late strut ice sheds for both 31 20 -3 150 4 25 0.50 139* 395 147.8 T = - 3 ° C tests 45 20 -3 150 4 25 0.50 132* 393 147.9 30 20 -6 150 4 25 0.50 247 477 136.6 44 20 -6 150 4 25 0.50 234 480 137.5 32 20 -9 150 4 25 0.50 239 526 156.6 33 20 -12 150 4 25 0.50 238 551 170.0 34 20 -17 150 4 25 0.50 224 595 172.6 National Aeronautics and Space Administration 10
Supercooled Liquid Icing – Size: AoA
• Smaller AoA ➔ larger ice accretion
• Smaller AoA ➔ fewer shadow zones
• More ice on ramp and strut LE on
the suction side
Pressure Suction Target Test Conditions Ice Accretion Measurements Side Side Col 2 Col 3 Col 4 Col 5 Col 6 Col 7 Col 8 Col 9 Col 10 Accretion Both Struts Main Body LE D Time T U AoA MVD LWC Ice Mass Ice Mass Ice Vol.
3 3 (min) (°C) (knots) (°) (μm) (g/m ) (g) (g) (cm ) 8 5 -17 150 0 30 0.45 33 208 43.9 9 5 -17 150 2 30 0.45 33 205 42.7 3 5 -17 150 3 30 0.45 35 188 39.8 0 5 -17 150 4 30 0.45 35 176 40.0 7 5 -17 150 4 30 0.45 33 184 39.4 National Aeronautics and Space Administration 11
Supercooled Liquid Icing – Size: Accretion Time
• Longer time ➔ larger ice accretion
• Double time ➔ ~ double ice mass
Pressure Suction Target Test Conditions Ice Accretion Measurements Side Side Col 2 Col 3 Col 4 Col 5 Col 6 Col 7 Col 8 Col 9 Col 10 Accretion Both Struts Main Body LE D Time T U AoA MVD LWC Ice Mass Ice Mass Ice Vol.
3 3 (min) (°C) (knots) (°) (μm) (g/m ) (g) (g) (cm ) 1 5 -17 150 4 18 0.45 33 105 35.5 9 10 -17 150 4 18 0.45 73 208 66.5 National Aeronautics and Space Administration 12
Supercooled Liquid Icing – Location: AoA
• Larger AoA ➔ greater shadow
zones on suction side
• Larger AoA ➔ pushed initial
impingement limit farther back
• Shadow and concentration regions
can be seen near strut junction
Flow
Suction Suction Side Side
AoA = 0 °
AoA = 2 °
AoA = 4 °
Main Body Strut Leading Edg e O
T = - 17 C, MVD = 30 μm, U = 150 knots
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Supercooled Liquid Icing – Location: MVD
• Smaller MVD ➔ greater shadow
zones on suction side
• Smaller MVD ➔ pushed initial
impingement limit farther back
• Shadow and concentration regions
can be seen near strut junction
Flow
Suction Suction Side Side Main Body
MVD = 18 μm MVD = 90 μm
Strut Leading Edg e O °
T = - 17 C, U = 150 knots, AoA = 4
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Supercooled Liquid Icing – Characteristic: T
• Warmer T ➔ glaze ice
• Ice more transparent with horn
geometries at leading edges
• More feather shedding
• Colder T ➔ rime ice
• Ice more opaque, white with
streamlined ice geometries
• Less feather shedding
Pressure Pressure Side Side O O
T = - 3 C
T = - 17 C
°
MVD = 30 μm, U = 150 knots, AoA = 4
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Supercooled Liquid Icing – Characteristic: MVD
• Smaller MVD ➔ More shedding
• MVD = 15 μm ➔ feather shedding
from 4 min until end of 10 min test
• MVD = 90 μm ➔ no shedding
MVD = 15 μm MVD = 90 μm
O °
T = - 17 C, U = 150 knots, AoA = 0
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Supercooled Liquid Icing – Surface Temperature: T
• Initial increase in surface temp due to latent heat release from freezing • Decrease in surface temp due to thicker insulating ice layer
Location of TCs
• Greater surface temp increase for colder T as latent heat
plotted below
released more quickly (freeze fraction for rime > glaze) • Amount of surface temp increase related to collection efficiency (LE > Base of Curve > Flat Section) Pressure O • Good repeatability for T = - 3 and - 6 C test pairs Side 3 °
MVD = 25 μm, TWC = 0.5 g/m , U = 150 knots, AoA = 4
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Supercooled Liquid Icing – Surface Temperature: MVD
• Initial increase in surface temp due to latent heat release from freezing • Decrease in surface temp due to thicker insulating ice layer
Location of TCs
• Greater surface temp increase for larger MVD (related to
plotted below
collection efficiency) • Amount of surface temp increase related to collection efficiency (LE > Flat Section) Pressure • Good repeatability for MVD = 30 and 50 μm test pairs Side O 3 °
T = - 17 C, TWC = 0.45 g/m , U = 150 knots, AoA = 4
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Summary
• A series of component - level icing tests utilizing SIDRM were conducted at NASA IRT in 2022 • Primary objective to collect icing data to develop and validate GlennICE accretion models
• Aerodynamic analysis: Data in good agreement with CFD simulations for various AoA
and airspeeds
• SCL icing analysis: Various parametric sweeps conducted to measure impact on ice
accretion size, location, characteristics, and test article surface temperature
• Larger cloud MVD, colder air temperatures, smaller angles of attack, and longer spray times
resulted in larger ice accretions
• Test article angle of attack and cloud MVD impacted the location of ice accretion
• Total air temperature and cloud MVD impacted icing characteristics
• Total air temperature and cloud MVD impacted surface temperature during ice accretion
• Good repeatability where test runs duplicated
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Acknowledgments and Contact
The authors wish to acknowledge the Power and Propulsion sub - project of the A dvanced
A ir T ransport T echnology Project ( AATT ) under the NASA A dvanced A ir V ehicles
P rogram ( AAVP ) for financial support of this work.
The authors would also like to acknowledge the efforts made by Jordan Salkin and
Quentin Schwinn in collecting and processing the 3D scanned icing geometry data.
Contact Information:
Tadas Bartkus
tadas.p.bartkus@nasa.gov
NASA Glenn Research Center
21000 Brookpark Rd.
Mail Stop 11 - 1
Cleveland, OH 44135
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