energirelaterad fordonsforskning konferens - drag reduction on passenger cars drag reduction on...
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Energirelaterad
fordonsforskning
konferens-
Drag reduction
on passenger
cars
Drag reduction on passenger cars through wake control and optimization
Lennert Sterken
October 8th, 2014
2014-10-08Lennert Sterken, Energirelaterad Fordonsforskning - Drag Reduction on Passenger Cars, 2014
Energirelaterad
fordonsforskning
konferens-
Drag reduction
on passenger
cars
Drag reduction on passenger cars through wake control and optimization
• Time period: Q1 2011 – Q1 2015
• Main participants: Volvo Car Group, Energimyndigheten
• Program: FFI Energi & Miljö, with 3 600 000 SEK
2014-10-08Lennert Sterken, Energirelaterad Fordonsforskning - Drag Reduction on Passenger Cars, 2014
Energirelaterad
fordonsforskning
konferens-
Drag reduction
on passenger
cars
content• Introduction
• Drag reduction: rear-end extensions• Numerical approach• Experimental correlation
• Unsteady methodology development• Numerical simulations• Differential pressure sensors
• Future work
2014-10-08Lennert Sterken, Energirelaterad Fordonsforskning - Drag Reduction on Passenger Cars, 2014
Energirelaterad
fordonsforskning
konferens-
Drag reduction
on passenger
cars
introductionMain research question:
• How can the rear wake be controlled and optimized such that the air resistance is reduced and that fuel consumption and CO2-emissions are lowered?
2014-10-08Lennert Sterken, Energirelaterad Fordonsforskning - Drag Reduction on Passenger Cars, 2014
Energirelaterad
fordonsforskning
konferens-
Drag reduction
on passenger
cars
IntroductionImprovement on UB to make rear-end changes more effective
2014-10-08Lennert Sterken, Energirelaterad Fordonsforskning - Drag Reduction on Passenger Cars, 2014
Red: Side panelsBlue: Tunnel panelGreen: Suspension panelYellow: Diffuser panelOrange: Engine-bay connection panel
Energirelaterad
fordonsforskning
konferens-
Drag reduction
on passenger
cars
Rear-end extensionsInitial numerical investigation
• Steady-state (RANS)• Realizable k-ε turbulence modelling
Extension design:• Straight vs. curved• Different lengths:
• 250mm, 150mm and 50mm
• Inclination change
2014-10-08Lennert Sterken, Energirelaterad Fordonsforskning - Drag Reduction on Passenger Cars, 2014
Energirelaterad
fordonsforskning
konferens-
Drag reduction
on passenger
cars
Wind tunnel correlationRapid prototyping of extension parts
• Multiple segments• Upper segments able to change
angle
2014-10-08Lennert Sterken, Energirelaterad Fordonsforskning - Drag Reduction on Passenger Cars, 2014
Energirelaterad
fordonsforskning
konferens-
Drag reduction
on passenger
cars
Effect on CD
2014-10-08Lennert Sterken, Energirelaterad Fordonsforskning - Drag Reduction on Passenger Cars, 2014
Reference: Improved underbody and closed cooling
Energirelaterad
fordonsforskning
konferens-
Drag reduction
on passenger
cars
Current investigationNew wave-like extensions, tested in CFD
• Further reduction of drag at 0° yaw• Stimulate break-up of the large flow structures
2014-10-08Lennert Sterken, Energirelaterad Fordonsforskning - Drag Reduction on Passenger Cars, 2014
Energirelaterad
fordonsforskning
konferens-
Drag reduction
on passenger
cars
Unsteady developmentContinuation of unsteady simulations
• Based on a DDES-approach with Spalart-Allmaras turbulence modelling
• Development on closed-front configurations summarized for publication in journal
• Further development of simulations with the inclusion of engine-bay
2014-10-08Lennert Sterken, Energirelaterad Fordonsforskning - Drag Reduction on Passenger Cars, 2014
Energirelaterad
fordonsforskning
konferens-
Drag reduction
on passenger
cars
Unsteady developmentPurchase of differential pressure sensors
• Combined with Ipetronik DAQ-system available at Volvo Cars
• First measurements conducted July• Will be presented at SAE World Congress 2015, Detroit
• Post-processing based on FFT-analysis and POD-analysis
2014-10-08Lennert Sterken, Energirelaterad Fordonsforskning - Drag Reduction on Passenger Cars, 2014
Energirelaterad
fordonsforskning
konferens-
Drag reduction
on passenger
cars
Future work• Analysis of unsteady measurements and simulation results
• Multiple techniques: FFT,POD, …
• Investigation of extension-shape design, limited to 50mm extension length
• Preliminary date for PhD defence: June 5th 2015
2014-10-08Lennert Sterken, Energirelaterad Fordonsforskning - Drag Reduction on Passenger Cars, 2014
Energirelaterad
fordonsforskning
konferens-
Drag reduction
on passenger
carsThank you for your attention
2014-10-08Lennert Sterken, Energirelaterad Fordonsforskning - Drag Reduction on Passenger Cars, 2014