Laser-induced iodine fluorescence technique for quantitative measurement in a nonreacting supersonic combustor

Abstract

A nonintrusive optical technique, laser-induced iodine fluorescence (LIIF), is demonstrated in the quantitative study of the compressible flowfield in a steady, nonreacting supersonic combustor. Measurements of density, temperature, and velocity were made with the calibrated technique for two combustor operating conditions. Measurements were first conducted in the supersonic flow over a rearward-facing step for comparison with calculated pressure profiles. The second operating condition was staged, transverse injection behind a rearwardfacing step at an injection dynamic pressure ratio of 1.20. These experimental results demonstrate the capability of the technique for making accurate, spatially resolved measurements of gasdynamic variables in the complex supersonic flowfield. Complete data sets to be generated with this technique will be used to validate computational fluid dynamic (CFD) codes for supersonic combustor flowfields, prior to the inclusion of chemical reaction.