Laser schlieren deflection in incident shock flow
Abstract
Initial laser schlieren deflections behind incident shock waves were recorded and compared with presently available theories. It is found that using a quadrant photodiode detector permits accurate assignment of time zero. High-sensitivity laser schlieren data were collected to determine the deflection due to wall boundary layer growth. When the observed deflections are compared with presently available flow models, it is found that laminar boundary layer growth only accounts for about half of the observed signal in non-relaxing test gas. Averaging local beam deflections over the finite beam profile, weighting by the Gaussian power distribution of the laser beam, was found to be a necessary correction if one attempts to study very high speed relaxation processes.
- Publication:
-
Shock Tubes and Waves
- Pub Date:
- 1980
- Bibcode:
- 1980stw..proc..555T
- Keywords:
-
- Boundary Layer Flow;
- Flow Deflection;
- Incident Radiation;
- Laser Applications;
- Schlieren Photography;
- Shock Waves;
- Gas Flow;
- Gauss Equation;
- Laminar Boundary Layer;
- Mathematical Models;
- Molecular Relaxation;
- Photodiodes;
- Wall Flow;
- Instrumentation and Photography