Document
National Aeronautics and Space Administration An
Initial Study
of the
Fundamentals of Ice Crystal Icing Physics
in the
NASA Propulsion Systems Laboratory
June 5 - 9, 2017
AIAA Aviation Conference
Peter Struk NASA Glenn Research Center Tadas Bartkus, Jen - Ching Tsao Ohio Aerospace Institute Timothy Bencic, Michael King, Thomas Ratvasky , Judy Van Zante NASA Glenn Research Center www.nasa.gov 1 National Aeronautics and Space Administration
Outline
• Introduction & background
• NASA Fundamental Ice Crystal Icing Research Goals
– Concepts using the NASA Propulsion System Laboratory (PSL)
• Experimental Description
• Results
– Freeze - out characteristics of cloud – Changes in aero - thermal conditions at the test section – Accreted i ce characteristics observed
• Summary
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Introduction
• NASA investigating the fundamental
physics of ice crystal icing (ICI)
Advance Air Transport Technology Project (AATT; 2015 +) Advanced Aircraft Icing (AAI) Subproject
• Challenging to study ice - accretion
physics directly inside the engine
Technical Challenge: Expand engine aero - thermodynamic – Trying to simulate local ICI environment modeling capability to predictively without using an engine assess the onset of icing in current and N+2/N+3 aircraft during flight operation (FY21 ).
• This paper presents an initial study of the
fundamental physics of ICI using PSL
The simulation tools are well anchored in
– Test occurred in March 2016
results from both fundamental physics studies and full engine tests.
– Select results presented
• Last year, presented preliminary work in preparation for this test – Complementary papers to follow www.nasa.gov 3 National Aeronautics and Space Administration
NASA Fundamental ICI Research Goals
Graphic: NASA (www.ueet.nasa.gov) Ice Crystal
• Identify and bound the
Icing
conditions affecting ice -
crystal ice accretion at the
(local) accretion site
Engine Tests Local Region
• Generate & characterize Link actual conditions in an
engine to fundamental work
(i.e. measure) those
conditions
𝑄 𝑐𝑜𝑛𝑣
• Gather data and develop 𝑄
𝑜𝑢𝑡
models on ice - crystal icing
𝑄 𝑄 𝑐𝑜𝑛𝑑 𝑖𝑛
factors
Local region requires more information than full - scale test (e.g. melt ratio) www.nasa.gov 4 National Aeronautics and Space Administration
Concept Using PSL
Match:
(1) wet - bulb
temperature
(2) particle size
distribution
(3) melted portion of
incoming ice
Goal : Ability to generate a prescribed mixed - phase condition at the
test section for fundamental ice - crystal icing research
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Fundamental Test #1
• Eight (8) days of testing occurred in March 2016
• Objectives
– Examine spray bar and plenum parameters and how they affect the mixed - phase at the exit of the free jet – Cloud characterization at the test section: • Melt ratio (fraction of freeze out) • Total water content • Temperature & humidity measurements at test section (cloud on vs. cloud off) • Particle size distributions • Uniformity – Observe ice accretion www.nasa.gov 6 National Aeronautics and Space Administration
PSL Configuration
8.84 m 29.0 ft 6.68 m 2.16 m 7.08 ft 21.92 ft TANK Inlet Constant Area Transition Ducts Ducts plane Free Jet PLENUM Exit plane Multi - wire Spray 0.91 m (test section) probe Bars 3.0 ft www.nasa.gov 7 ` National Aeronautics and Space Administration
Test Configurations
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Mixed - Phase Investigation
Plenum Relative Humidity Sweep Approach
Parameters Nomenclature
• Plenum / test section N 𝑜𝑧𝑧𝑙𝑒 𝑠 𝑚 𝑛𝑜𝑧 𝑇𝑊 𝐶 = 𝑒 – Total pressure, P (kPa) 𝑈 𝐴 0,i 𝑒 – Static pressure , P (kPa ) s,e 𝑚 𝑛𝑜𝑧 • Velocity, 𝑈 (m/s) 𝑒 𝑇 P 𝑤𝑎𝑡𝑒𝑟 s,e 𝑇𝑊 𝐶 – Total temperature, T ( ° C) 𝑚 0,i – Humidity, (g / kg dry) P i 0,i T 0,i 𝑈 • Spray bar 𝑒 i – TWC & Particle Size • P & P 𝑚 𝑛𝑜𝑧 air water • MVDi (IRT calibrated values) • Nozzle # Inlet Exit plane plane (test section) www.nasa.gov 9 National Aeronautics and Space Administration
Mixed - Phase Investigation
Plenum Relative Humidity Sweep Results
Water Content Measurement Results
P = 44.8 kPa (6.5 psia ) and 42.8 kPa (6.21 psia ) 0,i,T T = 7.2 C 0,i,T 3 * TWC = 6.5 g/m ( Estimated) e,T Liquid Liquid Glaciated b c d e Ice accretion cases a * www.nasa.gov 10 National Aeronautics and Space Administration
Mixed - Phase Investigation
Plenum Relative Humidity Sweep Results
Test Section T (static) and Melt Ratio
wb P = 44.8 kPa (6.5 psia) and 42.8 kPa (6.21 psia) 0,i,T T = 7.2 C 0,i,T 3 * TWC = 6.5 g/m ( Estimated) e,T Accretions b c d e Ice accretion cases a * shown on next slides www.nasa.gov 11 National Aeronautics and Space Administration
Ice Accretion Examples
Accretion “b” 8x actual speed
Low melt ratio (10 minute spray time)
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Ice Accretion Examples
Accretion “e” 8x actual speed
High melt ratio (10 minute spray time)
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Surface TC meaurements
Accretion “b” Accretion “e”
Low melt ratio High melt ratio
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Summary
• NASA conducting research on fundamentals of ICI: – Identify and bound the conditions at the (local) accretion site – Generate & characterize conditions – Develop models & gather data on ice - crystal icing factors
• Generate environment outside of an engine to facilitate study
– Using PSL as test bed • Presented data from an 8 - day test effort in March 2016, examining: – F reeze - out characteristics of cloud – Changes in aero - thermal conditions at the test section – Ice characteristics observed
• These result offer modelers a dataset to help develop and validate ice -
crystal, mixed - phase accretion models.
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Acknowledgement
• Financial support:
– NASA's, Advanced Aircraft Icing ( AAI) Subproject
• Mr. Tony Nerone, Project Manager
• Special thanks to:
– Staff of the NASA PSL
– Mr . Chris Lynch for his excellent imaging work .
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Questions
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Backup Slides
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Measurements
• Temperature • Total water content
– Rearward Facing – Isokinetic Probe – version
Temperature Probe 2
– Commercial TAT Sensor
• Liquid water content
• Humidity
– SEA Multi - Element Probe
– Spectra sensor WVSS - II
• Particle size distributions
• Pressure / velocity / Mach
– Cloud Droplet Probe
(CDP)
• Uniformity
– Cloud Imaging Probe
– Traverse RTFP
(CIP)
• Temperature
– High Speed Imager (HSI)
• Humidity
– Phase Doppler
– Condensed phase water
Interferometer (PDI)
• PSL Tomography
• Video cameras recorded
ice accretion
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Mixed - Phase Investigation
Plenum Relative Humidity Sweep Results
Test Section Changes is T and when cloud activiated
P = 44.8 kPa (6.5 psia) and 42.8 kPa (6.21 psia) 0,i,T T = 7.2 C 0,i,T 3 * TWC = 6.5 g/m ( Estimated) e,T Ice accretion cases a * b c d e www.nasa.gov 20