Bubbles, seeds, stones, and striae can be detected by illuminating the sample with a bright light and observing the scattered light. The use of a shadow graph or Foucault knife-edge (Schlieren) is very useful in detecting internal defects. In the Schlieren test, shown in Fig. 2-1, the irregularities become visible since they deviate light past the stop. If the surfaces are not polished, they ma...

Transitional shockwave/boundary layer interactions (SBLI) are studied experimentally. Experiments conducted on a hollow-cylinder flare model in the R2Ch blowdown facility at Mach number of 5 for three different Reynolds numbers transitional regime. Unsteady wall pressure measurements along with mean and unsteady heat flux high-speed Schlieren imaging. The images then processed using Proper Orth...

Synthetic schlieren is a new technique that allows one easily and inexpensively to visualise density variations, such as those caused by internal waves propagating in a density stratified fluid. In the special case of two-dimensional internal waves (for example, those created by an oscillating cylinder), synthetic schlieren allows one to measure nonintrusively the wave amplitudes everywhere in ...