FIRST STEPS TOWARD SPACE - Smithsonian Institution Libraries

NUMBER 10
In addition to a study of orbital paths (corresponding
to our transfer orbits), this work includes
considerations on the application of relativity to
energy radiation (REP anticipated photonic propulsion,
study of which has been undertaken recently
in some countries).
The principle of multistage rockets and the calculations
of mass ratios presented by REP stimulated
the work of Louis Damblanc, who in 1936
was awarded a patent for "self-driven projectiles
whose propulsive charge is distributed in several
combustion stages along the axis of the rocket." 50
REP also foresaw the advantage of rockets for the
study of the aurora borealis, which is the purpose
of many current sounding rockets.
After the publication of the supplement to his
book, REP was awarded his second annual Grand
Prize by the Societe des Ing^nieurs Civils de France.
On 22 June 1936, he became a member of the
Acaddmie des Sciences in the division "applications
de la science a l'industrie." 51
Some Experimental Works
Let us review some of REP : s experimental works
that enabled him to solve certain problems in an
original way (we owe the details of paragraphs 1—4
to Ing£nieur General J.-J. Barre, who sent us copies
of certain of REP's reports, the originals of which
have been destroyed).
1. Method of injecting fuel and oxidizer into the
combustion chamber.—REP first tried using a device
including volumetric pumps driven by a sort
of gas turbine turned by part of the jet from the
nozzle. This design was abandoned because of the
difficulties due to pump lubrication and the poor
behavior of the liquid-oxygen fittings. He then used
pressurized tanks for feeding the fuel and oxidizer.
This system worked by the pressure of an inert gas
on the fuel and by the action of a heater that raised
the pressure of the oxygen and vaporized part of it.
Figure 7 shows a particularly original device used
by REP's team. It is based on the fact that the
vapor pressure of liquid argon is 31.5 hpz at 140° K,
while the vapor pressure of liquid oxygen at this
temperature is 25 hpz. A bypass (7) operates at the
pressure of the liquid oxygen tank (3) and allows
the petroleum ether to pass at a rate sufficient to
maintain the pressure at 25 hpz, taking into account
the heat given off by the liquid oxygen to the
FIGURE 7.—Device for injecting fuel and oxidizer into the
combustion chamber. 1, Argon tank. 2, Coil exchanger. 3,
Liquid oxygen tank. 4, Release valve. 5, Petroleum ether tank.
6, Pressure gauge. 7, Heating by-pass regulator. 8, Petroleum
ether outlet. 9, Liquid oxygen outlet.
argon contained in tank (1). Relief valve (4), in
which the argon vapor is expanded at 25 hpz,
forces the petroleum ether from the tank (5) towards
the jets 52 either directly or through exchange
coil (2).
For the static tests at Satory (see 5, below), compressed
nitrogen was used to feed the fuel through
a relief valve. This device operated very safely,
provided the regulators were defrosted when necessary.
The major advantage was the remarkably low
dead weight, but it was not entirely satisfactory
when used for cold and dense gases, the mass of
which tends to become quite substantial.
2. Vibrating volumetric feed regulator.—REP
then conceived of a vibrating volumetric feed regulator
to control the liquid flow. Figure 8 shows the
working of a device designed according to the principle
of a double pendulum. The liquid leaves tank
(K) by two cylinders (C) and the ports of the slidevalves
(T) connected to pistons (P) by springs. The
slide-valves (T) were fixed to the cylinder frame by
springs. The entire system vibrated in resonance
with tank (K), whose vibrations could be tuned to
those of the piston/slide-valve assembly, by means
of closed tube (A). The liquid flow was thus provided
by equal and synchronous volume. This
device worked quite well during its first water test.
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