Aircraft Icing

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Aircraft Icing

• Mithun Varma

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The larger picture

• Understanding the flow over different types of
  iced airfoils
• Development and validation of new techniques for
  simulation of flows over complex geometry
• Satisfying FAA Aircraft certification
  requirements
• Make flights safer

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Weather accidents(1990 - 2000)
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Causes

• Wet clouds
• Cold Fronts
• Low pressure areas
• Isolated Air mass with plenty of moisture
• Freezing rain and drizzle

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Effects

• Distorts the flow of air over the wing
• Diminishes the wings maximum lift
• Adversely affects aircraft handling qualities
• Significant increase in drag

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Types of Ice formation

• Rime ice Rough, milky white in appearance, and
  generally follows the contours of the surface
  closely
• Glaze ice Clear and smooth, usually contains
  some air pockets
• Mixed ice combination of glaze and rime ice

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Glaze Ice
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(No Transcript)
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Mixed Ice on wing ice accretion on the engine
cowling
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Methods

• RANS (Reynolds Averaged Navier-Stokes) Approach
• LES (Large Eddy simulations)
• DES (Detached Eddy Simulations )

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Experimental VS Steady RANS results at zero AOA
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Experimental VS Steady RANS results at six
degrees AOA
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DES (Detached Eddy Simulations)

• Hybrid RANS-LES methodology
• For high Reynolds number wall-bounded flows

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Americas Cup
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Boat Geometry
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Surface mesh
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Keel Hub surface mesh
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Rudder surface mesh
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Keel Bulb
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Volume grid cut section
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THANK YOU ALL