Noise-resistant two-wavelength interferometry for single-shot measurement of high-gradient flows. (May 2023)

• Record Type: Journal Article
• Authors: Psota, Pavel; Çubreli, Gramoz; Šimurda, David; Šidlof, Petr; Kredba, Jan; Stašík, Marek; Lédl, Vít
• Is Part Of: Optics and lasers in engineering. Volume 164(2023)
• Publication Date: 2023-05
• Subjects: High-Speed -- Two-wavelength Interferometry -- Noise-resistant -- Supersonic -- Compressible Flow -- Wind Tunnel; Lasers in engineering -- Periodicals; Optical measurements -- Periodicals; Optics -- Periodicals; Lasers en ingénierie -- Périodiques; Mesures optiques -- Périodiques; Optique -- Périodiques; 621.36605
• DOI: 10.1016/j.optlaseng.2023.107505
• Languages: English
• ISSNs: 0143-8166

Abstract

Abstract: This paper presents a new robust approach to measuring dynamic phenomena with high gradients using two-wavelength high-speed interferometry. A multiplexed interferogram with two different wavelengths and spatial-carrier frequencies is captured by a single high-speed camera shot. Quantitative processing of the interferogram is based on Fourier analysis, which is followed by a robust procedure to retrieve the unwrapped phase map with single-wavelength accuracy but with an extended range of unambiguity. This method is significantly more noise-resistant than the standard two-wavelength technique, which is sensitive to noise and synthetic phase distortion. The method was successfully applied to studying shock waves in a transonic compressor blade cascade in an industrial aerodynamic laboratory, where single-wavelength and standard two-wavelength approaches fail.