Poster De Conférence Année : 2025

Combined Schlieren and Rayleigh Measurements to investigate Radiation Effects on Laminar Flame Speed and Flame Temperature in Methane-Air Spherical Flames

Résumé

In combustion process simulations, detailed models consider radiative emission and absorption effects of gases. In order to evaluate the performance of these models, spherical expanding flames (SEF) can be analysed with regard to differences in laminar flame speeds and flame temperature profiles of the burned gases. For this purpose, a combined high-speed Schlieren and time-resolved Laser Rayleigh Scattering (LRS) measurement technique is introduced in this work to simultaneously capture flame propagation speed and time resolved flame temperature profiles, respectively. Spherically expanding stoichiometric methane-air flames were measured in an optically accessible constant volume chamber at ambient temperature and an elevated pressure of 5 bar. A pulsed high-power LED emitting red light was directed through an optical lens system before being captured by a high-speed CCD camera to image the evolution of the flame radius. A focused continuous-wave laser beam and a high-speed CMOS camera were employed to capture Rayleigh scattering images. Spherically expanding flames were simulated for adiabatic and radiation affected cases. Radiation was considered using an optically thin model (OTM) and a fitted statistical narrow-band correlated-k model (SNB). It is demonstrated that the Rayleigh scattering technique can quantitatively resolve temperature profiles in the burned regions of spherically expanding flames. The sensitivity of the LRS results to minor pressure increase during the combustion process is demonstrated. A comparison between the simulated and experimental temperature profiles indicates good agreement in peak temperature values. Notably, a strong correlation in the temperature gradient was observed for the SNB model, while the OTM model overpredicted the temperature decrease in the burned gas. Future work will aim to reduce uncertainty by minimizing background noise and improving the setup for further microgravity applications.

Fichier non déposé

Dates et versions

hal-05026550 , version 1 (09-04-2025)

Identifiants

  • HAL Id : hal-05026550 , version 1

Citer

Joachim Beeckmann, Frederik Mohr, Fabien Halter, Miguel Buenaflor, Zheng Chen, et al.. Combined Schlieren and Rayleigh Measurements to investigate Radiation Effects on Laminar Flame Speed and Flame Temperature in Methane-Air Spherical Flames. 12th European Combustion Meeting, Apr 2025, Edinburgh, Scotland, United Kingdom. ⟨hal-05026550⟩
337 Consultations
0 Téléchargements

Partager

  • More