Multi-parameter measurements approach based on two-dimensional Interferometric Rayleigh Scattering with structured illumination

摘要

In order to understand the basic phenomena and essential rules of the turbulent combustion, it is important to make quantitative visualization measurements of flow structure, temperature and velocity A multi-parameter measurements approach based on two-dimensional Interferometric Rayleigh Scattering was proposed. The working principle of two-dimensional Interferometric Rayleigh Scattering was described. A modified detection method utilizing structured laser illumination was used to solve the problem of signal overlap between the reference interference signal and the flow interference signal. In order to ensure the correct decoupling of two-dimensional interference image, two-dimensional distribution of the effective etalon finesse was measured in advance, whereas the phase change of light was monitored comparing to an unshifted reference interference signal. A two-dimensional Interferometric Rayleigh Scattering measurement system with a 20-beam probe laser, aspherical lens collection optics, and a solid Fabry-Perot etalon in static imaging mode was set up. An interference image with about 500 measurement points was obtained and analyzed. Finally, a two-dimensional velocity, temperature and density with a spatial resolution of 0.15 mm in height and 0.13 mm in length were reconstructed. Rayleigh scattering; interference; multi-parameter measurements; Fabry-Perot etalon; structured laser illumination