1. ELF Aerodynamic Analysis
By Resolved Analytics

2. Free Body Diagram Forces on the ELF, FD = ½ ρυ2CDA FRR = CRRFG P = FvFL
FD = ½ ρυ2CDA
FRR = CRRFG
P = Fv
FG = 500 lbs - FL
CD = ???
CRR = 0.005
A = 1.39 m2 FD
FRR FM FG

3. Computational Fluid Dynamics Model Results – 20 mph
CD = 0.32

4. Computational Fluid Dynamics Model Results – 20 mph

5. Addition of Floor Addition of floor improved Cd by ~ 3.5%
Created an “up-wash” effect in rear of vehicle by keeping flow attached under the vehicle

6. Addition of Doors/Windows
Sides completely closed in
Model results show increase in Cd and more recirculation along side walls vs. interior of vehicle
Baseline
With Doors

7. Body Taper Front to Rear
~3 degree taper angle from front to rear
Slight Decrease in Frontal Area due to geometry of cut
Model results show Increase in Cd and less interior recirculation than baseline
Tapered Panel Top Plan View
Tapered Panel Front View

8. Body Taper Front to Rear
Baseline
Tapered

9. Body Taper Front to Rear
Tapered
Baseline
Plan View, Cut Just Along Upper Wheel Well.
Baseline Has More Narrow Wake (slightly). Flow Struggles to “Hug” Side Panel
of Tapered Vehicle behind Wheel Wells. Tapered Vehicle Has Same “Blockage”
Due to Wheel Wells.