A non-axisymmetric temperature field reconstruction method based on the interferometric fringe schlieren method

Abstract

The typical non-axisymmetric temperature field distribution in the tail nozzle outlet area of the combustion chamber of an aircraft engine can reflect the operating state of the engine. As an effective non-axisymmetric temperature field non-contact measurement method, the traditional background oriented schlieren method has the problem that the extraction accuracy of light deflection is not high. In this paper, interference fringes are introduced into the schlieren measurement, and the highly sensitive fringe offset replaces the traditional background speckle offset for measurement, which realizes the accurate reconstruction of the non-axisymmetric temperature field. Firstly, through the Interferometric stripe schlieren composed of multiple sets of double-slit interferometric systems and imaging sensors, the offset of the interference fringe after passing through the non-axisymmetric temperature field is measured by image processing, and the spatial refractive index field is reconstructed by the