tire water splash - ansys · 10/31/2012  · tire water splash dragos moroianu volvo cars...

Tire Water Splash

Dragos Moroianu Volvo Cars Corporation Andreas Blixt FS Dynamics

Overview

• Background

• Model description

• Results

• Implementation

• Conclusion

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Background

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• What is splash?

• Why is splash a problem?

• Current splash CAE method description

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What is splash

• Speed between 30-65km/h

• Water depth 20-80mm

• Higher depth... Wading

• Even higher depth ... submarine

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• To protect pedestrians from water

What is the problem with splash?

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What is really the problem with splash?

• Engine bay water contamination

• High water loads on critical components

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Experiments

provide qualitative

information

Numerical (DPM) - hard to estimate

trajectory after wall interaction

Background – Current approach

Numerical (DPM) - hard to estimate

trajectory after wall interaction

Experiments

provide qualitative

information

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Side Splashing

a

w

Model Description

Forward Splashing

b

w

D

4D

11D

3D

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Model Description

• Incompressible flow

• Multiphase (liquid/gas) - VOF

• Large Eddy Simulation

• Smagorinsky subgridscale model

• Polyhedral mesh

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Model Description

• Velocity inlet gas: 8.3 m/s

• Velocity inlet liquid: 8.3 m/s; 50 mm thickness

• Symmetry plane

• Pressure outlet

• Moving wall – translation on ground with 8.3 m/s; rotation on wheel with ~25 rad/s

• Cell size – tire surface 1.25 mm, volume characteristic edge 5 mm, max. 40 mm

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D

4D

11D

3D

Results Results monitoring point

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Water tire splash of an isolated wheel

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Splash – front view

Water tire splash of an isolated wheel

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Splash – top view

Water tire splash of an isolated wheel

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Splash – side view

Water tire splash of an isolated wheel

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Splash - view from underneath

Water tire splash of an isolated wheel

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Splash – rear view

Example of Implementation

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Conclusion

• Good frequency agreement with experiments

• Good qualitative agreement with experiments

• More work is needed for a robust procedure

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Questions?

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