STAR European Conference 2010 AERODYNAMICS DEVELOPMENTS ON A LE - - PowerPoint PPT Presentation

STAR European Conference 2010 AERODYNAMICS DEVELOPMENTS ON A LE MANS PROTOTYPE ORECA 01 LMP1

1. ORECA Presentation 2. Why we use CFD?

• 2009 Aero Development
• 2010 Aero Development

3. Methodology

• Correlation
• Case Studies
• Mesh
• Results

Conclusions

PRESENTATION

ORECA:  Since 1972  180 People  35 to 40 Millions Euros / year  4 divisions:

 Engine department (Magny-Cours)  Marketing + Incentive  Race parts + accessories sales  Race team + Chassis Engineering

• 1. ORECA

ORECA:

 RACE TEAM:

 Endurance Racing (LMP1 – 2 cars)  Audi R8 GT3 (French GT – 2 cars)  Formula Le Mans  Other projects (engineering / production)

 Engineering:

 11 Engineers  Aero-group : 6 engineers, 4 working on Star-CCM+

• 1. ORECA

2009 CFD Development

We used CFD for :

• Comprehension of LMP aerodynamics
• Keep the development of aero-package up through the season

We chose Star-CCM+ for :

• Only one interface
• Ratio simplicity / accuracy / cost
• Evolution of the Software through the year
• 2. Why we use CFD?

2009 Aerodynamic Development:

 Oreca 01 :

• Adapt to new ACO Aerodynamics rules (reduction of the rear wing dimensions)
• New aero-package for Courage LC70E LMP1

 Tests : ~80% Wind tunnel, ~20% CFD

• 320 runs using a 40% scale model in ACE wind-tunnel (Magny-Cours).
• CFD development : 1 engineer (1 Workstation) working on Star-CCM+ / +80 simu.
• 2. Why we use CFD?

2009 CFD Development

History ORECA 01 V1: introduced in 1000 km Spa (May 2009) ORECA 01 V2: introduced in 1000 km Silverstone (Sept. 2009). Developped 100% using CFD. Increasing Efficiency and Downforce

95 97.5 100 102.5 105 107.5 110 112.5 115 2008 car 2008 car + 2009 wing ORECA 01 V1 ORECA 01 V2

Efficiency

• 2. Why we use CFD?

• 2. Why we use CFD?

• 2. Why we use CFD?

1,5 0,082

• 0,141
• 0,916
• 1

1 2 3 4 5 6 7 Race1 Barcelone Race2 Spa Race3 Algarve Race5 Silverstone

Qualifying performances Le Mans Serie 2009

ORECA 01 Position Aston Position

• 2. Why we use CFD?

2010 Aerodynamic Development:

 Oreca 02 :

• New LMP1 car designed to compete for 24H of Le Mans (2011) with Peugeot Engine

 Tests : ~20% Wind tunnel, ~80% CFD

• CFD development : 4 engineers on Star-CCM+
• 4 Workstations, 1 Cluster of 128cores / 130 simulations in 1,5 month

Why we use more CFD in 2010?

 Ratio Cost / Efficiency  Understanding the phenomena and not iterating mechanically  Aero development through the year  Investment : cluster and SKILL  New skills = new business opportunities

• 2. Why we use CFD?

Methodology:

• Correlation

Straight-Line Test with the real Car Lift : calculated with Loadcells on each suspension + Pitot sensor Constant speed Drag : Coast-down. All the values are stored in a PI Data Analysis System:

• 4 Loads
• Aero Speed
• Ride Heights Front and Rear
• Acceleration X, Y, Z
• Ground Velocity
• 3. Methodology

Methodology:

• Case Studies

 Straight-Line Half-car with different Ride Heights  Yaw / Roll Full car with Yaw, Roll, Steering Angle

• 3. Methodology

 Slipstream

• 3. Methodology

DRAG LIFT EFFICIENCY LEADING CAR FOLLOWING CAR BALANCE LEADING CAR FOLLOWING CAR

Front

• Mesh / Solver

 Mesh : Wrapper + Trimmer + Prism Layer From 12M, up to 45M of cells  Physics :

• Steady cases
• Unsteady : coming soon...
• Porous Region for Radiators
• Velocity specification on wheels and Floor
• RANS + SST K-Omega
• 3. Methodology

• 3. Methodology

• 3. Methodology

• Results

90% of the post-treatment is automated:  Scenes – Starview files  Analitic Results : force reports, mass-flow Force and Mass-flow reports automated by Java macros All Results compiled in Excel File

• 3. Methodology

• 3. Methodology
• Results - Starview

• 3. Methodology

• 3. Methodology

• 3. Methodology

• 3. Methodology

• 3. Methodology

• 3. Methodology

• Results – Analytic

By macros, we export analytic results: – Forces on each parts – Mass Flow : brake ducts, radiator – Flow around the underfloor : velocity, pressure, angle – Plots of Coefficient of Pressure : Rear Wing, Front Wing, Undefloor, Diffuser

• 3. Methodology

• 3. Methodology

– Forces on each parts

• 3. Methodology

23% 43% 39% 17%

• 19%
• 1%

0%

• 1%
• 30%
• 20%
• 10%

0% 10% 20% 30% 40% 50% Wing Front Splitter Flat Bottom Diffuser Bodywork Front Wheel Rear Wheel Internal

SCZ

17% 19% 9% 13% 11% 3% 8% 20%

• 30%
• 20%
• 10%

0% 10% 20% 30% 40% 50% Wing Front Splitter Flat Bottom Diffuser Bodywork Front Wheel Rear Wheel Internal

SCX

• 3. Methodology

– Flow around the underfloor : velocity, pressure, angle

• 3. Methodology

– Plots of Coefficient of Pressure : Rear Wing, Front Wing, Undefloor, Diffuser

Conclusions

 Since 2 years, ORECA has invested a lot to increase its know-how, methodology and tools to carry extensive Aero development programs on Le Mans Prototypye. We started from Zero and have now an efficient aero-group. Our staff is on a steep learning curve.  The effort we have put in the Aero development started to pay off at the end of the 2009 season. We expect a bigger gain to come with the new LMP1.  We open with the CFD new business opportunities  Our aim is to fight with factory Teams in 2011.

Special Thanks to  Vincent Keromnès, Christian Fauchier, Christophe Gayet from CD Adapco France.  ORECA’s technical partners: CD Adapco, Dassault System, Araldite, MSC Software.