FIRST STEPS TOWARD SPACE - Smithsonian Institution Libraries

NUMBER 10 169
1933. The test records of this new field of engineering,
i.e., engineering of ramjet engines, have been
preserved to this day. 6 Record No. 1 briefly stated:
At 2:30 a.m. the knife switch of the facility electric motor
was activated. . . The compressor was stopped at 2:45 a.m.
. . . After 15 minutes had elapsed pressure in the final
compression stage had reached 190 atm.
Owing to the participation and support of the
whole personnel of GIRD the testing and the final
adjustment of the facility successfully advanced
and after six tests it was fully prepared for the investigation
of the ramjet engine model.
Figure 3 shows the ignition of various combustible
air-fuel mixtures and their rates of combustion.
It was decided to carry on the experiments on
ramjet engine models in the IU-1 test stand with
gaseous hydrogen, the most available and convenient
from the point of operation, which when
mixed with air is ignited in a very wide range and
ensures the highest rate of combustion.
In the early morning of 15 April 1933 the first
test of the ramjet engine model was conducted. It
lasted 5 minutes. The conclusion of the test results
stated: "The first starting of the engine has proved
the theoretical suppositions about jet engines propelled
by a gaseous propellant." The test marked
the beginning of experimental research on ramjet
engines.
Four days after the first test the second one was
carried out on the IU-1 stand. This time the engine
was tested at pressures in the combustion chamber
FIGURE 2.—Experimental ramjet engine.
varying from 1 to 3.2 atm. During the test period
the engine was started 3 times and it was established
that "under normal engine performance the ignition
of hydrogen-air mixture should be done only
once, on starting the engine. The combustion chamber
having been heated, the ignition may be cut
off and the power is adjusted only by means of air
and propellant supply."
As the work of testing the ramjet engine models
proceeded, the methods of investigation were gradually
modified. From 9 June 1933, the thrust developed
by the engine under the test was measured
during experiments on the IU-1 test stand.
To make the ramjet engine effective not only at
supersonic velocities but at subsonic ones as well,
designs of ramjet engines were researched in which
the air, in addition to being compressed in the diffuser
due to the air flow kinetic energy, was also
compressed by means of certain devices. One of such
design was the pulse-jet engine (PuVRD), with the
valve at the entry (the prototype jet engine of a
pilotless "flying bomb" known later in Germany
as the V-l).
To investigate the possibility of developing the
pulse-jet engine in GIRD, in June 1933 an experimental
combustion chamber with a valve labelled
EK-3, was constructed.
The test of pulse-jet engines in 1933 in GIRD
permitted a determination of the main problem
occurring when developing the design of engines
of such type, and an estimate of the volume and
difficulties of their solution. It was decided for the