Investigation of low-density hypersonic and plasma flows by schlieren system using various light sources

The results of an experimental investigation of low-density hypersonic and plasma flows using a schlieren system with various light sources are reported. In addition to the commonly used Nanopulser, two other pulsed light sources – LED and laser breakdown – are employed. As expected, the Nanopulser furnishes excellent, short-duration illumination pulses although illumination varies from shot-to-shot. Laser breakdown supplies short-duration, incoherent illumination that is constant from pulse-to-pulse. LED systems provide excellent steady illumination with significant advantages such as lower cost, monochromatic light and pulsed- and continuous-mode operation.