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

PRESENTATION 1. ORECA Presentation 2. Why we use CFD?  2009 Aero Development  2010 Aero Development 3. Methodology  Correlation  Case Studies  Mesh  Results Conclusions

1. ORECA 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+

2. Why we use CFD? 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 Efficiency 115 112.5 110 107.5 105 102.5 100 97.5 95 2008 car 2008 car + ORECA 01 ORECA 01 2009 wing V1 V2

2. Why we use CFD?

2. Why we use CFD?

2. Why we use CFD? Qualifying performances Le Mans Serie 2009 7 ORECA 01 Position Aston Position 6 5 4 3 2 1,5 1 0,082 0 -0,141 -0,916 -1 Race1 Barcelone Race2 Spa Race3 Algarve Race5 Silverstone

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

3. Methodology 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 LEADING CAR FOLLOWING CAR LEADING CAR FOLLOWING CAR Front DRAG LIFT EFFICIENCY BALANCE

3. Methodology  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  Results - Starview

3. Methodology

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 – Forces on each parts

-30% -20% -10% 10% 20% 30% 40% 50% 0% 23% Wing 43% Front Splitter 39% Flat Bottom 17% Diffuser -19% Bodywork -1% Front Wheel SCZ 3. Methodology 0% Rear Wheel -1% Internal -30% -20% -10% 10% 20% 30% 40% 50% 0% 17% Wing 19% Front Splitter 9% Flat Bottom 13% Diffuser 11% Bodywork 3% Front Wheel SCX 8% Rear Wheel 20% Internal

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.