% new material BLIMPS? blimp0.tex This file not used
See also blimp2014.tex
Blimps and submarines
Submarines
HMS Conqueror -- 4900 tonnes; 103 crew; speed 28 knots;
% 14.4 m/s 52 km/h
% 87m x 10.1mx8.2m
powered by one RR PWR nuke.
% Delivered power: 20,000 shp.
Delivered power: 15\,MW\@.
% 20\,000\,hp.
So, counting all crew as passengers, it delivers
transport at
% 20000 hp / 28 knots in kWh / km
% 288 kWh/km
% 2.80 kWh / pkm
280 kWh / 100 pkm.
% That's using delivered power. If we count the thermal energy,
% should prob multiply by 4?
% see aplan.tex for nuclear ship info
% http://en.wikipedia.org/wiki/Submarine_Cargo_Vessel
Submarine cargo vessels have been proposed, but not yet built.
A Russian Typhoon-class submarine could carry
15\,000\,t of cargo at 16--18\,knots (31\,km/h).
% (displacement 26000t)
% the military version does 27\,knots using two PWRs totalling 180MWt
% I assume this would use just one of them - 90MW\@.
% 90MW / (15000 ton * 17 knots ) in kWh/ (ton * km)
% 0.19 kWh/tkm.
Roughly 0.2\,kWh/tkm.
\section{Blimps or airships. zeppelin, dirigible.}
A blimp uses an enormous helium-filled balloon, which is lighter than air,
to counteract the weight of its little cabin.
Is there any point in blimps for transporting people or freight
from A to B?
First, let's compare a blimp with a car, van, or truck.
The choice is:
either we move the cabin from A to B with a huge balloon
strapped to the roof, or with wheels strapped to the base of the
cabin. With the balloon strapped on the roof, we add to the air resistance.
With wheels instead, we add rolling resistance.
We must also ensure that roads are constructed and maintained from A to B\@.
Let's assume the road is in place.
What speed would you like to go at?
At any speed bigger than (20 mph?),
the energy consumption of a road vehicle is dominated by its
air resistance. Under these circumstances, it is a crazy idea to massively
increase the air resistance.
Only at very low speeds could a blimp conceivably be better than road transport.
What if there are no roads?
For example, are blimps useful for transport across seas?
Fundamentals:
Diameter $d=10$\,m.
Assume drag coefficient of 0.03, like a plane.
air resistance, which is the force required, which is the
energy per distance, is
$\frac{1}{2} c_{\rm d} \rho \Ap v^2
=
$
More work here....
84km/h.
Don't need to use energy staying up.
inability to overfly large mountain ranges.
Hindenburg's top speed having been 135 km/h (84 mph), the current airship "Spirit of Dubai" (a Skyship 600) can achieve only 50-80 km/h (30-50 mph), and the Zeppelin NT up to 125 km/h (78 mph).
Actual cost of operating an AI 600 between new york and
atlantic city.
Estimated 4.5 million dollars.
\tinyurl{37ozsq}{http://www.aiaa.org/content.cfm?pageid=406&gTable=mtgpaper&gID=13460}
http://links.jstor.org/sici?sici=0003-049X(1928)67%3A4%3C319%3ALM%3E2.0.CO%3B2-U
20 truckloads of goods straight from a factory in Japan to a warehouse in California in a day and a half, bypassing crowded ports and clogged rail lines.
Airships for freight
Airships to replace short-haul planes
coat with polymer PV?
check power required.
and size?
%`Electric Airships are still great idea, but the implementation is
%hard. I worked on a solar airship program for 4 years, and we got a
%20m electric airship to fly at low altitudes. The problem lies in
%efficiency \& brittleness of solar cells, UV degradation, and the
%amount of power required to generate lift and deal with the wind
%velocities.'
% new material BLIMPS? blimp0.tex
\myurl{http://www.aerosml.com/aeroscraft.asp}
\myurl{http://www.aerosml.com/airships.asp}
\myurl{http://www.aerosml.com/aeros-40D_spec.asp}
Avgas 100
This is the standard high octane fuel for aviation piston engines and has a
high lead content. There are two major specifications for Avgas 100. The
ASTM D 910 and UK DEF STAN 91-90. These two specifications are
essentially the same, but differ over antioxidant content, oxidation stability
requirements and max lead content.
Avgas 100 is dyed green.
43.5 Mj/kg low HV
48.8 MJ/kg high HV
13.57 kWh/kg
ok, let's go with 13.6
density 0.72 kg/l v similar to motor gasoline
34.7 MJ/l ?
Airship Length / 46.6 m
Max Flight Speed 51 mph / 82kmh
Operating Altitude Range 0 - 2133m
Envelope Length / 45.6 m
Envelope Max Diameter / 10.6 m
Envelope Volume Max 2833 m$^3$
Engines 2 Teledyne Continental 4-Cylinder motors, IO-240-B
Max Power 93.2 kW ea.
Fuel Reserve (basic model)
45.141 Litters (30min. maximum continuous power)
Fuel Capacity
287 Litters (usable)
Fuel Consumption
34kg/Hour (@75\% Cruise for 2 engines) (ie 462 kWh/h)
Empty Weight
1,895.5 Kg
Useful Load
980,5 Kg
Number of Seats
5, Including 1 Pilot
Area exposed to sun roughly 300\,m$^2$.
1000\,W/m$^2$ sun
assume 5\% efficiency (lightweight PV)
15\,kW in full sun.
Or 60\,kW if revolution in lightweight PV gives 20\%.
But it uses 180kW\@.
Absolute Airship Speed Record
Zeppelin NT Friedrichshafen, Germany
60.4 knots (111.8 km/h)
27 October 2004
\myurl{http://www.stevefossett.com/html/main_pages/records.html}