ELF Aerodynamic Analysis By Resolved Analytics

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

Computational Fluid Dynamics Model Results – 20 mph CD = 0.32

Computational Fluid Dynamics Model Results – 20 mph

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

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

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

Body Taper Front to Rear Baseline Tapered

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.