SkyTran's
super energy efficiency
Time for some basic
aerodynamic, physics and math lessons!
The chart shown here
should give you some basic insight into the
importance of using optimized streamlined shapes in transportation vehicles.
AERODYNAMIC DRAG 
D 
= 
C_{d} 
X 
A 
X 
q 
Aerodynamic
Drag
Force
(pounds) 

Aerodynamic Drag Coefficient (dimensionless) 

Projected Frontal Area (square feet) 

Dynamic Pressure (pounds per square foot) 
THE SHAPE
EFFECT
(a measure of how streamlined a body shape is) 
THE SIZE EFFECT 
HOW SPEED (V) AND
DENSITY(ρ) ARE TAKEN INTO ACCOUNT 
EQUAL DRAG BODIES 
CUBE 
C_{d}
= 1.05 
C_{d}A
= 1.05 ft^{2} 

Flat plate "B" has 56% of the drag of flat plate "A".
"C" only has 25% the drag of "A".
"D" only has 6% of the drag of "A". 
q=1/2ρV^{2 }
=(VMPH)^{2}/391 
(at sea level, 59^{0}F) 
Speed 
Dynamic Pressure 
0 mph 
0 
10 mph 
.25 lb/ft^{2} 
20 mph 
1.02 lb/ft^{2} 
30 mph 
2.30 lb/ft^{2} 
40 mph 
4.09 lb/ft^{2} 
50 mph 
6.39 lb/ft^{2} 
60 mph 
9.20 lb/ft^{2} 
70 mph 
12.53 lb/ft^{2} 
80 mph 
16.37 lb/ft^{2} 
90 mph 
20.72 lb/ft^{2} 
100 mph 
25.58 lb/ft^{2} 
150 mph 
57.54 lb/ft^{2} 

A =1.0 ft^{2}

SPHERE 
C_{d}
= .47 
C_{d}A
= 1.05 ft^{2} 
A =2.13 ft^{2}

CHOPPED TEAR DROP 
C_{d}
= .10 
C_{d}A
= 1.05 ft^{2} 
A =10.5 ft^{2}

TEAR DROP 
C_{d}
= .05 
C_{d}A
= 1.05 ft^{2} 
A =21 ft^{2}

The product C_{d}A
is called the EFFECTIVE FRONTAL AREA. 
This next section shows some
of the output from
our Power Consumed calculation spreadsheet. It properly accounts for aerodynamic
drag, magnetic drag and linear motor efficiency loss effects. This small
section of the spreadsheet shows the calculated costs of electrical energy to move a fully loaded SkyTran vehicle
a distance of 100 miles (at 100 mph no less!). The spreadsheet then
compares this efficiency to a 20 mile per gallon car using $2.30 per gallon
gasoline. You can download our Excel spreadsheet here for free and do
the "what ifs" using your own car's MPG efficiency, local gasoline prices & electrical
rates. Obviously, the calculated SkyTran EQUIVALENT MPG figure will come out different
every time. Final results will very much depend on whether you own a Hummer,
a Prius Hybrid or something in between.
If the industrial electricity rate for power =

8 
cents per kilowatthour 



Energy cost to travel 100 miles by SkyTran =

$ 0.71 




Compare this to your car that gets 
20 
MPG (miles per gallon) of gasoline 
costing 
$ 2.30 
per gallon 



Energy cost to travel 100 miles by your car =

$ 11.50 

Thus, a 20 MPG car costs 
16.2 
times what SkyTran does for energy 
CLICK HERE
to DOWNLOAD this Excel Spreadsheet
so you can do your own
power required calculations
plus predictions for EQUIVALENT Miles Per Gallon.
Why are the SkyTran vehicles so
compact?
Why did you seat the SkyTran passengers in tandem
instead of the more logical sidebyside position?
At first glance many people
think we should make our SkyTran vehicles larger to carry more passengers.
They don't realize that even changing passenger seating from tandem to
sidebyside involves significant energy efficiency penalties. The
following table gives you numbers to ponder. Don't forget that the
cost of the structure for building any guideway will be directly related to
the weight carried. Envision the difference between one structure
designed to carry legal 80,000 pound gross weight trucks and another
designed to carry 700 pound gross weight vehicles!
Possible SkyTran/UniModal
Configurations 
Prone  Solo
Absolute minimum teardrop 
Single Seater
Sports car like
reclined seating 
Two Passenger
Tandem 
Two Passenger
Side by Side 
Four Passenger
Two Front,
Two Rear 





Performance Comparisons of Possible
SkyTran/UniModal Configurations 

Prone  Solo 
Single Seater 
Two Passenger 
Two Passenger 
Four Passenger 
Absolute minimum teardrop 
Comfortable
with
20 lbs luggage 
Tandem 
Side by Side 
Two Front,
Two Rear 
Pod Weight (lbs) 
100 
150 
200 
270 
350 
Max People Wt (lbs) 
200 
200 
500 
500 
1000 
Total weight (lbs) 
300 
350 
700 
770 
1350 
Frontal Area (sq ft) 
0.88 
6.067 
6.067 
12.2 
12.2 
Drag Coefficient 
0.12 
0.168 
0.168 
0.22 
0.22 
CdA product (sq ft) 
0.1056 
1.018 
1.018 
2.684 
2.684 
Air Drag Horsepower @ 100 MPH 
3.38 
6.94 
6.94 
18.298 
18.298 
MagLev Horsepower @ 100 MPH 
1.60 
1.87 
3.73 
4.10 
7.19 
Total Horsepower @ 100 MPH 
4.98 
8.81 
10.68 
22.40 
25.49 
kW power to track @ 100 MPH 
4.13 
7.30 
8.85 
18.56 
21.12 
Energy Cost per 100 miles 
$0.33 
$0.58 
$0.71 
$1.48 
$1.69 
Equivalent MPG 
697 
394 
325 
155 
136 
Relative Efficiency 
214% 
121% 
100% 
48% 
42% 
Acceleration Power req'd (kW) 
20.6 
36.5 
44.3 
92.8 
105.6 
Assumes: 20 MPG car & $2.30/gallon gas = $11.50/100
miles; Electricity (industrial) @ $.08 per kWhr; SkyTran @ 100 MPH. 
Don't forget there is all
kinds of research is currently being done to improve the fuel efficiency of
automobiles. Hybrids, fuel cells, direct natural gas or hydrogen
burning, etc. One has to ask oneself what happens to congestion
even if an affordable 500 MPG automobile is invented? If it
is a standard 4 or 5 passenger size it will unfortunately take up the same space on today's
roads and
will do nothing to eliminate congestion. Even something as
advanced as the Rocky Mountain Institute's four passenger, 100 MPG, HyperCar
concept is a futile effort when it comes to alleviating congestion.
Unless you build personal
sized vehicles that use offline stations operating on an elevated 3D grid (in
order to eliminate the average speed
killing stopping and starting of any form of group transit and all red light
type 2D intersection stopping) you cannot do
anything significant at any reasonable cost to reduce daily
commuting congestion hassles.
To maintain car culture
heaven, the cities need to build 10
times the current number of freeways. Imagine what would happen to
congestion if the government could afford to build 6 lane freeways
crisscrossing everywhere. Especially if each intersecting node had
nonstop cloverleaf exit and merging ramps. SkyTran offers exactly
that at affordable costs!
Energy Efficiency
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