Wave-field structure in active bubble systems in shock tubes with "discontinuities" in cross section
V. K. Kedrinskii, I. V. Maslov, and S. P. Taratuta
Lavrent'ev Institute of Hydrodynamics, Siberian Division,
Russian Academy of Sciences, Novosibirsk 630090
Pages: 256-263
Abstract
The wave structure in active bubble
media in shock tubes with sudden changes
of profiles in the form of
"discontinuities" in cross section and a
one-phase liquid waveguide is analyzed
numerically. In axisymmetric
formulation, the paper studies wave
amplification due to reflection from a
wall and focusing at the butt-end of a
rigid rod aligned coaxially with the
channel. In this configuration, the
amplification effect results from two-
dimensional cumulation of the shock wave
after it leaves the annular channel and
reaches the butt-end of the rod. A Mach
configuration forms in the focus spot.
The geometrical characteristics of the
shock tube allow one to control (to some
extent) the amplification coefficient
and the coordinates of the focus spot.
In particular, it is shown that the wave
can be focused near the second
discontinuity of cross section — a rigid
wall (in the region of passage through
the interface to the waveguide) — and
intensified upon reflection. If the
waveguide radius is equal to the height
of the Mach stem, the reflected wave has
a maximum amplitude.
|
