doug knight wrote: > Make a shock tube. Have made one using propane air mixture using OTS > components. Piping was most expensive part. > > If that test gives value to what you are trying to understand. Indeed - setting up meaningful instrumentation (as with any transient supersonic experiment) is no doubt the complicated part of using such a system for any observation of genuine interest. What does high speed photography of visual effects related to shock waves (doesn't one really want a specialized optical system to visualize such things?) actually elucidate? -dave w