Density Perturbations Induced by a Sluing Laser Beam.
Abstract
A theoretical and experimental investigation of the density perturbations induced by absorption in a sluing laser beam has been conducted with emphasis on transonic crossflows. A linearized theory for the time-dependent density perturbations induced after turning on an arbitrary heat distribution within an arbitrary crossflow has been developed and programmed for routine computations. A closed-form solution has been obtained for the special case of sonic crossflow (M = 1) and a uniform heat distribution. The limits of validity of the linearized theory are obtained for M near one and large time. An experiment was conducted to compare the density perturbations predicted by linearized theory with experimental observations. A cw HF laser beam was rotated across an absorption cell located within a Mach-Zehnder interferometer. Fringe shifts were observed, as predicted by linearized theory, when the crossflow (sluing rate) was subsonic. No fringe shifts were observed at transonic speeds partly because of the onset of nonlinear effects.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 15, 1975
- Accession Number
- ADA013739
Entities
People
- Harold Mirels
- John W. Ellinwood
- Robert L. Varwig
Organizations
- The Aerospace Corporation