This paper presents further results of an ongoing experimental and numerical investigation into the unsteady process of
blast wave reflection from straight smooth surfaces. It is shown that basic blast wave phenomena such as the transition
from regular to irregular wave reflection can be adequately and conveniently studied in a laboratory environment by
using small charges with masses in the milligram range. While the laboratory scale generally provides greater
accessibility, it also imposes more stringent conditions on the diagnostics than the large-scale environment. The paper
reviews the previously found considerable discrepancies between numerical and experimental results for the location xtr
of the transition from regular to irregular wave reflection. These are caused by the initially minuscule size and gradual
growth of the Mach stem and the limited resolution of the recording material. Different techniques are used to improve
the accuracy of the experimental determination of the transition point, and a new combination of modern high-speed
photography with the traditional soot technique is shown to be the most promising tool for this purpose.
In Extracorporeal Shock Wave Lithotripsy (ESWL) underwater shock wave focusing generates high pressures at very short duration of time inside human body. However, it is not yet clear how high temperatures are enhanced at the spot where a shock wave is focused. The estimation of such dynamic temperature enhancements is critical for the evaluation of tissue damages upon shock loading. For this purpose in the Interdisciplinary Shock Wave Research Center a technique is developed which employs laser induced thermal acoustics or Laser Induced Grating Spectroscopy. Unlike most of gas-dynamic methods of measuring physical quantities this provides a non-invasive one having spatial and temporal resolutions of the order of magnitude of 1.0 mm 3 and 400 ns, respectively. Preliminary experiments in still water demonstrated that this method detected sound speed and hence temperature in water ranging 283 K to 333 K with errors of 0.5%. These results are used to empirically establish the equation of states of water, gelatin or agar cell which will work as alternatives of human tissues.