1st Ice Prediction Workshop ResultsAnsys / Bombardier

Isik OzcerAlberto PueyoShezad NilamdeenYue ZhangHabib FouladiCristhian AliagaShoaib ShahJeya Selva

Ansys in-flight icing simulation methodology

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Ansys in-flight icing simulation methodology overview

Initial CAD/Mesh, unstructured

Air flow, RANS, sand-grain roughness, HTC

Droplet flow, Eulerian,Size distributions

Wall film flow & icing for ∆t, Ice roughness & ice shapes

RemeshingAero analysis, 3D printingMultishot iterations:

Fully automatedSame grids for all solversUser-free remeshing

Boundary/initial condition update

1 shot of icing simulation

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ICE3D: ice accretion and runback module

Qice

Qimp

QevapQconv

Qcond

roughness, turbulence

Transient FVM

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Solvers and settings used for the workshop

• RANS solver: FENSAP- Compressible, Finite element method- Spalart-Allmaras with sand-grain roughness

(0.5mm, 1mm)- Steady-state, CFL, 300-400 iterations

• Droplet flow solver: DROP3D- Finite element method- Steady-state, CFL, 100-200 iterations- Customizable size distributions- SLD modeling

• Breakup: Pilch & Erdman • Splashing & Bouncing: Mundo• Runback water and bouncing droplet reinjection

• Icing and runback: ICE3D- Finite volume method- Transient with automatic time step size- Constant and variable ice density (beta 21R2)

• Multi-shot - Remeshing: Fluent Meshing- Mesh resolution:

• 1mm minimum edge size• 5-deg max face-to-face

- Number of shots = 10

Collection efficiency cases

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Collection efficiency: Horizontal tail

Case 111: MVD 21, 27-bin Case 112: MVD 92, 27-bin

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Collection efficiency: Multi-element airfoil

Case 121:MVD 21 27-bin

Case 122:MVD 9227-bin

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Collection efficiency: Nacelle

Case 131:Low mass flow

Case 132:High mass flow

A B C D E

A B C D E

2D Icing cases

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2D NACA 23012 resultsFENSAP-ICEExperiment

Case 242Ts = 266KMVD = 15µm LWC = 0.8 g/m3

V = 103 m/sτ = 5 minρice = 917 kg/m3

Case 241Ts = 250KMVD = 30µm LWC = 0.4 g/m3

V = 103 m/sτ = 5 minρice = 917 kg/m3

18-inch NACA 23012

Case 251Ts = 261KMVD = 22µm LWC = 1.6 g/m3

V = 103 m/sτ = 6.6 minρice = 779 kg/m3

Case 252Ts = 261KMVD = 22µm LWC = 1.6 g/m3

V = 103 m/sτ = 6.6 minρice = 776 kg/m3

72-inch NACA 23012

3D Icing cases

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Swept NACA 0012 MCCS, constant ice density (experimental)

Case 361Ts = 257KMVD = 35µm LWC = 0.5 g/m3

V = 103 m/sτ = 20 minρice = 538 kg/m3

Case 362Ts = 266KMVD = 35µm LWC = 0.5 g/m3

V = 103 m/sτ = 20 minρice = 459 kg/m3

Case 363Ts = 263KMVD = 21µm LWC = 0.5 g/m3

V = 115 m/sτ = 18 minρice = 620 kg/m3

Case 364Ts = 260KMVD = 21µm LWC = 0.5 g/m3

V = 114 m/sτ = 18 minρice = 660 kg/m3

Case 371Ts = 257KMVD = 32µm LWC = 0.5 g/m3

V = 103 m/sτ = 20 minρice = 437 kg/m3

Case 372Ts = 266KMVD = 32µm LWC = 0.5 g/m3

V = 103 m/sτ = 20 minρice = 402 kg/m3

FENSAP-ICEExperiment

30o swept NACA 0012 45o swept NACA 0012 30o swept NACA 0012

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Variable ice density model (case 362)

ρice = 917 kg/m3

Solver setting variations, roughness, shot length, mesh size, etc.

Void Density (AIAA-2014-2200)Void Density (AIAA-2014-2200)

Void density

Impact ice density

Case 361Ts = 257KMVD = 35µm LWC = 0.5 g/m3

V = 103 m/sτ = 20 minρice = 538 kg/m3

Case 371Ts = 257KMVD = 32µm LWC = 0.5 g/m3

V = 103 m/sτ = 20 min

Case 362Ts = 266KMVD = 35µm LWC = 0.5 g/m3

V = 103 m/sτ = 20 min

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Swept NACA 0012 MCCS, variable ice density

Case 361Ts = 257KMVD = 35µm LWC = 0.5 g/m3

V = 103 m/sτ = 20 min

Case 363Ts = 263KMVD = 21µm LWC = 0.5 g/m3

V = 115 m/sτ = 18 min

Case 364Ts = 260KMVD = 21µm LWC = 0.5 g/m3

V = 114 m/sτ = 18 min

Case 372Ts = 266KMVD = 32µm LWC = 0.5 g/m3

V = 103 m/sτ = 20 min

FENSAP-ICEExperiment

30o swept NACA 0012 45o swept NACA 0012 30o swept NACA 0012

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Swept wing numerical ice shape (case 362)

10-shot, 1.0mm mesh 20-shot, 1.0mm mesh 40-shot, 1.0mm mesh 20-shot, 0.7mm mesh

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Swept wing numerical ice shape (case 362)

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Closing remarks

• SLD modeling needs work- Bouncing criteria- Sensitivity to droplet temperature through water viscosity- Numerical experiments, VoF & SPH methods, machine learning for data reduction

• Ice density modeling- Strong factor- Variable density is the way to go, could be better – research opportunity!

• Multi-shot step size- More shots bring out more details in the ice shape- How can it be automated, with some “resolution” dial?

• Future workshop ideas- Performance degradation analysis on the ice shapes created by participants in IPW1 (exp. possible)- Less cases please, deep dive into methods, modeling

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Additional slides

Horizontal tail Cp

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Three Element Airfoil

High Lift, Three Element AirfoilStructured mesh (created using ICEM CFD) (BKFINEGRID)480,798 nodes238.936 hexahedral cells

Three element airfoil Cp

Case-131: Surface Mach

Reference: NASA CR 4257

Optional

Calculated using P-total at test section inlet

Reference: NASA CR 4257

Optional

Calculated using P-total at test section inlet

Case-132: Surface Mach

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Case-362 – variations

k=0.5 k=0.2 k=0.5, LangD k=0.5, gravity k=0.5, mesh 0.0007 k=0.5, mesh 0.0013k=0.5, mesh 0.0013, Jones Glaze