Application of Pneumatic Aerodynamic Technology to Improve Drag Reduction, Performance, Safety, and

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Application of Pneumatic Aerodynamic Technology
to Improve Drag Reduction, Performance, Safety,
and Control of Advanced Automotive Vehicles
by Robert J. Englar, Georgia Tech Research
Institute
Application of Advanced Pneumatic Aircraft
Technology.
...Through Analytical Experimental Development
...
..To Proof-of-Concept Full-Scale Tests
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Outline of Presentation
Introduction Pneumatic Heavy Vehicle
Aerodynamic Technology Pneumatic Heavy Vehicles
(PHV).Multi-Purpose Aero Devices for
Force Moment Reductions or Augmentations
Drag Reduction (Fuel Efficiency) or Drag
Increase (Aero Braking) Increased
Stability (Directional Lateral)
Improved Safety of Operation Reduced
Spray Turbulence Hydroplaning
No-Moving-Part Integrated System
Pneumatic Cooling System
Wind-tunnel Investigations Confirmations
Initial Full-Scale Tuning Tests at Volvo Trucks
SAE Type II Fuel Economy Tests at TRC Other
Applications Pneumatic SUV Aero Heat
Exchanger Conclusions Summary of Wind-Tunnel
Full-Scale Results
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Basics of Circulation Control Pneumatic
Aerodynamics and Application to Heavy Vehicles
Circulation Control Concept on Aircraft
Navy A-6/CCW Flight Test Aircraft
Blowing on Front of
Trailer and/or All 4 Trailing Edges

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Pneumatic Aero Development at GTRI Showed 50(or
more) Drag Reduction, Force Moment Augmentation
from Blown Configurations, andDrag Increase for
Aero Braking if Desired
-23.9
-10.2
DCD due to Blowing -26.8

4 Blown Slots Jet Turning on Rear Doors of
Wind-Tunnel Model
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GTRI Extended Cm Tests Showed State-of-the-Art
Drag Reduction!!
1999 Corvette Coupe
1999 Ferrari 550
2001 Honda Insight
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Directional Control Capability Provided by
Blowing of Left Side Slot Only (Similar Effects
on Drag)

Yaw Nose Left, Blow HERE
Additional Gain from Side Blowing Reduced CD
due to Yaw
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Static Jet Turning Displayed During Full-scale
Run-up Testing
Tufts
Slots, 4 total, one per side

Setting Slot Heights and Confirming Jet Turning
at Low Blowing Rate on Aft Door of Trailer
Right Rear Corner, looking up-- Tufts Show Jet
Turning to Left 90 on Side and 30 on Top
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On-the-Road Operation Jet Turning Entraining
the Freestream Flowfield and Reducing Vehicle Drag
Rear View with Jets Blowing
Close-up of Tufts Showing Jet Turning
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Pneumatic Heavy Vehicle (PHV) Test Rig on Track
for Fuel Test 1 at TRC, 75 mph with Blowing

SAE Fuel Test I Results 5-6 Fuel Economy
Increase 10-12 CD Reduction New Wind
Tunnel Tests were Conducted to Identify Initial
Problem areas, then Fuel Test II was conducted
in Sept. 2004
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Updated PHV Blown Wind-tunnel Model to Resemble
TRC Test Rig,With New Tractor, New Top Strut
Mount, New TE Geometry
Airfoil Airfoil
Tests of this new model completed at GTRI Showed
31 Lower CD than Stock Truck
Air Supply Line
Faired Mounting Strut
New Blown Trailing-edge Geometry, 53 Trailer
Generic Conventional Model (GCM) Cab (DOE Team
design)
Optional Gap Side Plates
High Floor, Wheels Undercarriage Details, No
Fairing
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Second SAE Type II Fuel Economy Test at TRC

Revised Pneumatic Heavy Vehicle Test Rig
Baseline Stock Heavy Vehicle Control Truck
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SAE Fuel Economy Results at TRC, Test 2 -
Improvements due to Blowing and Aft Trailer
Geometry

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Fuel Usage in the US (look at SUVs), and One
Possible FixIncrease Fuel Efficiency of SUVs
DOE Fuel Usage Data, 109 gallons/year
Blown SUV in Lockheed Tunnel

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Full-Scale Tunnel Tests of Unblown SUV to
Locate Flow Separation for Blowing Slot Location
of Pneumatic SUV

Smoke Flow over Unblown SUV , Testing in Lockheed
16 x 23 Low Speed Wind Tunnel, Marietta GA
Separated Flow over Aft Door of SUV
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Pneumatic Capabilities of Blown SUV Confirmed in
WT TestBlowing Configs far from Optimized


Drag Reduction or Aero Braking Functions
Interchangeable Which Slot Blown
Directional Stability, No Moving Parts
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CONCLUSIONS Pneumatic Aerodynamic Concepts Now
Demonstrated Full-Scale on PHV and PSUV

• Blowing Demonstrated on Full-Scale PHV Tests at
  TRC, Confirming Drag Reduction,
• but less than from Tunnel Tests Reasons Now
  Identified
• ?? 15-16 Fuel Efficiency Improvement is Possible
  Based on 31 Model CD Reduction
• TRC Track Test Results Show 11-12 Fuel
  Economy Increase due to Blowing
• and Aft Geometry (not including blower
  fuel better blower or pump would help)
• ?? Pneumatic Yaw Stability, Side-Wind CD
  Reduction, and Aero Braking Capabilities
• (Safety of Operation) are Confirmed, Model
  Full-scale Testing
• ? Pneumatic Full-scale Tunnel Tests Showed
  Similar Blown Capabilities for SUVs
• Lets get this on Production Trucks Fleets!!
  (12FEI2.4 Billion gals of diesel/yr)
• GTRI PATENTED
• CONCEPTS

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BACKUP Slides


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The Effects of Blowing on Increasing Base
Pressure for CD Reduction
TheVertical Mid Base

Vertical Mid Base
Horizontal Mid Base
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Flow Visualization of Blowing Jets

Tuft Showing Flow Uniformity at Diffuser Center
Combined Jet Strength and Wake Contraction (see
Shirt)
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Blowing Efficiency Drag/Thrust Increment Due to
Blowing Slot Position, shown as Fraction/Multiple
of Blowing Momentum Input
Its possible to get back 5.5 times the Cm input
as a CD Reduction. OR 2 times the Cm input as
Aero Braking increase