DOI: 10.1615/TSFP2
TIME EVOLUTION OF TWO-DIMENSIONAL VELOCITY FIELDS IN GAS-PHASE REACTING AND NON-REACTING TURBULENT JETS
RÉSUMÉ
The time evolution of two-dimensional (2-D) velocity fields in gas-phase reacting and non-reacting turbulent jets is experimentally observed using a newly developed kilohertz frame rate cinema Particle Imaging Velocimetry (cinema PIV) system. Up to 8000 instantaneous PIV images per second are obtained, with continuous sequence lengths exceeding 4000 images. The combination of high image acquisition rate and sequence length shows relatively long histories of time incremental changes in the velocity field, enabling observation of the time evolution of turbulent structures such as vortex convection, line and sheet formation, merging, and dissipation. Application of the method to a lifted turbulent jet flame reveals the interaction between turbulent vortex structures and the flame thermal boundary position. These results are uniquely suited to aid the development and validation of computational models used in simulation of turbulence and turbulent combustion, such as Large Eddy Simulation (LES).