Three-components Particle Image Velocimetry measurements in premixed flames

This paper presents results of the application of the stereoscopic Particle Image Velocimetry (SPIV) technique for the analysis of turbulent premixed flames. With respect to conventional PIV, which allows the measurement of t he in-plane components of the velocity in a plane, the stereoscopic PIV con figuration yields also the out-of-plane component. Principles of operation along with a description of the implemented set-up and accuracy assessments will be given in the paper. The availability of planar three component vel ocity fields significantly enhances the capability of inferring three-dimen sional flows in a correct and detailed manner. In addition, applying PIV to flames, topological information on the instantaneous reacting zones can be deduced by the observation of the seeding particle density in the recorded images. Premixed flames are investigated in jet configuration. The turbule nt combustion regime is at the transition zone between the regimes of the c orrugated flamelet and the thin reaction zones. Gas acceleration and stream line deviation. associated with volumetric expansion across the flame front , are well resolved by means of the three-component velocity field interpre ted in light of the particle Mie scattering visualization of the reacting f low. The evolution of turbulent motions passing through the flame front and local quenching phenomena due to the stretch effect in the presence of pre ferential diffusion are also presented and discussed. (C) 2001 Editions sci entifiques et medicales Elsevier SAS.