View Single Post
Old 08-08-2009, 03:33 PM   #26 (permalink)
Master EcoModder
aerohead's Avatar
Join Date: Jan 2008
Location: Sanger,Texas,U.S.A.
Posts: 11,742
Thanks: 18,906
Thanked 6,089 Times in 3,733 Posts
Project-update#4 ( Specifications)

Al's still busy so here's some quanta on the trailer at 89.5 man-hours into the project: [ Height = 43-inches (1075mm)], [ Width = 72-inches (1,800mm )], [ Length = 139.75-inches (3,439.75mm)], [ Frontal Area = 12.363-square feet (1.144 square meters)], [ Fineness-ratio (gross) = 3.25:1, 1.625:1 (free-air).---------------------------------------- Drag (pounds force at 70 mph) as estimated from Technical Aerodynamics,Wood: (a) faired axle = 0.69825, (b) faired wheels = 4.028, (c) faired leaf-springs = 1.113, (d) inverted-reversed hull with Mair' 22-degree boat-tail addition = 16.998.------------------------------------------- Total aerodynamic drag force at 70-mph = 22.837 pounds * ( this is for the trailer going through the air by itself with no vehicle in front,or in a wind tunnel by itself )--------------------------------------------- Rolling Resistance Force of trailer @ 500-pound design weight,70-mph,bias-ply 50-psi tires (4.80 X 8 ),from F= [ 0.0148 w + 0.000442(v-66)w] = 7.40 pounds.------------------------------------------ Total drag of trailer ( aero and RR) = 22.837 + 7.40 = 30.237 pounds at pull-bar.------------------------------------NOTE: A 65% "weight gain" to the CRX cost 2-mpg on the highway.The FrankenViking constitutes a 15% weight gain to the T-100.------------------------------------------------------------- Drag coefficient,T-100 ( with present kit) Cd 0.235(estimated from GM Aero Labs protocol.Drag coefficient of T-100 pulling a "conventional trailer, Cd 0.156 ( from Hucho: NASCAR-draft research.------------------------ Drag coefficient of FrankenViking, Cd 0.128,as per Technical Aerodynamics protocol and doubling Cds for ground-effect. Drag coefficient of FrankenViking as a "towed" structure, Cd 0.051,as per Hucho.----------------------------------- Presently the T-100,without boat tail,has a clean exit aperture of 59% Af,about 17.12 square-feet of turbulent wake.The addition of gap-fillers and trailer reduce the wake area to under 1.5 square-feet,a 95% wake reduction compared to the stock T-100.----------------------------------------------- The original Road Load Horsepower for the T-100,at 70 mph is approximately 43.413-HP at the drive wheel.With the gap-filler trailer,the road horsepower is estimated to drop to 21.997-horsepower ( 50.67% of original power).------------------------------------- If fuel consumption follows road load power,then the addition of streamlining package and gap-filler trailer theoretically could translate into a 50% mpg improvement at 70-mph over the stock pickup,perhaps 36-mpg interstate/38-mpg HWY.Barring the unforeseen,I should know something by mid-September.
  Reply With Quote