Measuring physical flow properties, such as density and temperature, at high frequency in high temperature and pressure environments is very challenging. Rapid fluctuations of these properties often have an impact on combustion efficiency and stability. We hereby attempt to measure density fluctuations in high-pressure premixed combustion using high temporal resolution laser Rayleigh scattering. The Rayleigh scattering intensity was assessed by counting individual photons due to the low signal to noise ratio. The measurement system was first verified at various air pressures without combustion. Combustion experiments were then conducted at four different pressures, from 1 to 7 bar. The density fluctuations increased with pressure, but the dominant fluctuation frequency decreased. Proper orthogonal decomposition analysis of high-speed schlieren images of the flame front was used to verify the results.
High frequency Rayleigh scattering measurements of density fluctuations in high-pressure premixed combustion
Note: This paper is part of the special topic, Light, X-ray, and Neutron Scattering of Flow.
Han June Park, Sangeun Bae, Hyungrok Do, Wontae Hwang; High frequency Rayleigh scattering measurements of density fluctuations in high-pressure premixed combustion. Physics of Fluids 1 August 2022; 34 (8): 081701. https://doi.org/10.1063/5.0102330
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