Aerodynamic Development of a Time-Trial Bicycle

Helmet: from CFD to Tour de France

LX R&D IS A CONSULTING FIRM SPECIALIZED IN

ENGINEERING SIMULATION & PRODUCT DEVELOPMENT

CFD FEA

LOUIS GARNEAU OFFERS A CYCLING SOLUTION WHICH

INCLUDES A ONE STOP SHOP FOR ALL YOUR CYCLING NEEDS.

TT Helmet Development history

5

Prologue 2004 Rocket 2006

SuperLeggera 2008 Rocket Air 2007

Development Process

Before: without CAE

6

Clay Model Tooling Prototypes

Wind Tunnel

Testing

Go to market

Development Process

Now: with CAE

7

3D CAD CFD/CAD iterations

Rapid Prototyping

Wind Tunnel Testing

Tooling Go to

market

Analysis of SuperLeggera

• 3D scan of helmet

• 3D scan of cyclist

• CFD Analysis

• Correlation with wind tunnel tests

8

Ideas for improvement

• Reduce frontal area (structural design)

• Improve air intake position & internal ventilation

ducts

• Reduce helmet sensitivity to angle of attack and

cross-winds

• Keep dimples (marketing)

9

Vortex generators

10

Scan + 3D CAD

Scan + 3D CAD

CFD Analysis: Meshing

CFD Analysis: Meshing

CFD Analysis: Set-up

• Mesh : 10 M polys

– volumetric controls around cyclist, helmet and

wake

• Speed : 60 km/h

• Turbulence model : SST (Menter) K-Omega

– y+ most around one, majority below 10

CFD Analysis: Frontal Area

Internal Ventilation Ducts

CFD Analysis: Ventilation

CFD Analysis: Ventilation

CFD Analysis: Vortex generators

CFD Analysis: Vortex Generators

CFD Results

Reduced drag

Less sensitivity to angle of attack

Improved ventilation

Advantages of CFD

PERFORMANCE

Wind Tunnel Testing

Wind Tunnel Testing

Choice of Mirinda Carfrae, World Champion Triathlete

Wind tunnel test: Superior drag reduction & ventilation

CFD for Marketing

Tour de France TT

QUESTIONS?