Publications
Simultaneous 10 kHz three-dimensional CH2O and tomographic PIV measurements in a lifted partially-premixed jet flame
High-speed, three-dimensional (3D) scalar-velocity field measurements were demonstrated in a lifted partially-premixed dimethyl-ether/air jet flame using simultaneous laser-induced fluorescence (LIF) of formaldehyde and tomographic particle image velocimetry (TPIV). The 3D LIF measurements were conducted by raster scanning the laser beam from a 100 kHz pulse-burst laser across the probe volume using an acousto-optic deflector. The volumetric reconstruction of the LIF signal from ten parallel planes provides quasi-instantaneous 3D LIF measurements that are synchronized with 10 kHz TPIV measurements. The temporally resolved formaldehyde-LIF and velocity field data were employed to analyze Lagrangian particle trajectories and displacement speeds at the base of the lifted flame. The particle trajectories revealed flow structures that are difficult to observe in an Eulerian reference frame. Positive and negative displacement speeds were observed at the formaldehyde-LIF surfaces at the inner and outer regions of the jet flame with a maximum displacement speed of approximately eight times the laminar flame speed of a stoichiometric dimethyl-ether/air mixture.