Transcript Drag reduction on passenger cars

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