Detector Assessment for 1D Single-Shot Spontaneous Raman Scattering for Temperature and Multi-Species Measurements in Flames

H. Ajrouche , A. Lo (1) , P. Vervisch (1) , A. Cessou (1)

1 CORIA - Complexe de recherche interprofessionnel en aérothermochimie

The critical aspect of 1D single-shot Spontaneous Raman Scattering (SRS) experiments in flames is the requirement of high efficiency of the detection system associated with a fast temporal gating. Single-shot SRS measurements in flames are performed either with ICCD or with back-illuminated CCDs associated with a fast shutter. Two types of back-illuminated CDD detectors are used: a back-illuminated CCD (BI-CCD) and electron multiplying CCD (BI-EMCCD). The purpose of the present paper is to compare the three detectors: the ICCD with its intensifier gating and the back-illuminated CCDs with a Pockels cell shutter developed in a previous work (Ajrouche et al, 2015). The accuracy and uncertainty of 1D single-shot SRS measurements of temperature and density are quantified in near-adiabatic CH4/air flames. This is performed for N 2 number density (high signal levels), and CO number density (low signal levels) corresponding to signal close to the detectability limit. The temperature is determined by modeling the vibration-rotation spectra of N 2 offering advantage of not requiring reference temperature and the modeled spectra are used as smoothed spectra to determine the instantaneous number densities. On one hand, the BI-CCD with the Pockels cell shutter is the most efficient detection systems in extreme low light situations for single-shot temperature measurements, and on the other hand the BI-EMCCD is the most powerful tool for best detectability of low density species.

Mots clés: Spontaneous Raman Scattering; Temperature; species number density; Combustion

Domaines: Milieux fluides et réactifs

H. Ajrouche, A. Lo, P. Vervisch, A. Cessou. Detector Assessment for 1D Single-Shot Spontaneous Raman Scattering for Temperature and Multi-Species Measurements in Flames. 18th International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanics, Jul 2016, lisbon, Portugal. ⟨hal-02392354⟩