Fig.11 shows the pressure distribution in the fluid domain in the
first 0.2 ms, with frame rate of 10 ms. The colours do not have
the same values in the frames, since the figure is only used to
clarify the origins of the high-frequency oscillations in the pressure
traces. The graph (at the lower right-hand corner) represents the
pressure history at the middle of the base (lower left-hand corner of
each frame). At the instant of impact, the fluid away from the wall
has no information about wall movement and a wave starts travelling
at the unconfined speed of 1485 m/s ð
ffiffiffiffiffiffiffiffiffi
K=r
p
Þ, producing
a pressure magnitude of 41.6 bar ðr$cun$DvÞ. This high pressure
region is clearly visible in the middle part of the bottle base (frames
2 and 3). On the other hand, fluid particles next to the bottle wall
start moving radially outward due to deformation of the wall. This
fluid movement radiates a radial decompression wave towards the
bottle axis. After approximately 30 ms (D/2cun ¼28 ms) the wave
reaches the axis (p