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Fig. 6.18
Temporal dynamics of static pressure
P
st
(Torr) measured near swirl flow axis in setup
SWT-1F at high-frequency plasma-on (below red rectangles) and plasma-off
6.11
Conclusions
This work is a continuation of Kapitsa's experiments on BL modeling (Kapitsa
1955
; Kapitsa
1969
). We repeated his experiments with the help of modern
diagnostic instrumentation. His main experimental results were proved in our work.
A number of new important data on the longitudinal vortex plasmoid creation and
its physics have been obtained by us, namely:
1. A stable nonequilibrium heterogeneous longitudinal vortex plasmoid is created
by a capacity-coupled high-frequency discharge in swirl flow. This longitu-
dinal vortex plasmoid consists of a hot plasma kernel (
T
V
3,200
˙
400 K,
T
R
2,000-3,000 K) and an extended warm plasma halo (
T
V
3,200
˙
400 K,
T
R
600 K). This compact longitudinal vortex plasmoid is created by both
the continuous high-frequency power pumping and the pulse repetitive high-
frequency power pumping in swirl flow. Note that the stable longitudinal vortex
plasmoid is created by the pulse repetitive high-frequency power pumping in
swirl flow at high modulation frequency
F
M
>
F
M
*
1kHz(
T
i
D
0.5 ms) only.
2. There is an energy exchange between the vibrational energy levels of the excited
nitrogen molecules and the translation energy of these molecules in the longitudi-
nal plasmoid (by the V-T relaxation process). This result is based on the analysis
of the obtained optical spectra of the longitudinal vortex plasmoid luminescence
at different swirl flow parameters, different high-frequency power settings, and
different values of the initial pressure
P
st
D
40-760 Torr. Experimentally, it was
impossible to realize this phenomenon in noble gas swirl flows (for example, in
argon).
3. Vortex attenuation and its decay by the capacity-coupled high-frequency dis-
charge plasma was found both in the duct and in the open air. The static
pressure near the vortex axis increased up to 20-50% at the capacity-coupled
