Geoscience Reference
In-Depth Information
3.5
3.0
pulse duration
τ
= 140 us
τ
= 300 us
2.5
2.0
1.5
1.0
0.5
0.0
1
10
100
duty cycle
Fig. 6.8
UV intensity dependence on duty cycle in longitudinal high-frequency plasmoid in free
swirl flow.
P
st
10
5
Pa;
V
t
V
ax
30 m/s
nonequilibrium longitudinal vortex plasmoid. So, the longitudinal vortex plasmoid
is the source of the intensive UV radiation and, may be X-ray radiation (Kapitsa
1969
). X-ray radiation connected with events of some BL impacts is also considered
in some reports (Barry
1980
;Avaramenkoetal.
1994
; Grigorjev
2006
), but its nature
has not yet been explained.
6.7
Gas Dynamic Characteristics of the Vortex Longitudinal
Plasmoid
Airflow around the longitudinal vortex plasmoid was studied simultaneously by
the optic interferometer and pressure transducers. The typical high-speed frames
of this vortex plasmoid and the gas flow behind it (in the hot wake) obtained
by this interferometer are shown in Figs.
6.9
and
6.10
. It is noted that a hot gas
wake is absent behind this longitudinal vortex plasmoid. It was seen that there is
a considerable temperature jump on the plasmoid surface in swirl airflow. The gas
temperature changes from
T
g
2,000 K inside the longitudinal vortex plasmoid up
to
T
g
600 K outside it. The typical contact surface width in this plasmoid is about
3-5 mm (Fig.
6.9
). This temperature jump was also measured by a thermocouple.
The physics of this anomalous phenomenon is not clear today (see following).
It is necessary to continue the experimental studies of this phenomenon to clarify
the physical mechanism of this thermal insulation of a longitudinal vortex plasmoid
in swirl airflow.
