Velocity and Temperature Measurements in Turbulent Diffusion Flames

Nonintrusive, time- and space-resolved measurements of velocity and temperature were performed in turbulent diffusion flames. The velocity measurements were made with a laser Doppler velocimeter on a confined turbulent hydrogen diffusion flame in co-flowing air. Mean velocity, velocity standard deviation and turbulence intensity profiles were produced and compared with high speed shadowgraph movies and a visual measurements of the flame boundaries. Single point velocity probability density functions (pdf) were also produced for all spatial measurement points. Temperature measurements were made using Rayleigh scattering on an unconfined turbulent diffusion flame. The fuel and its products had approximately the same Rayleigh scattering cross-section as air so that temperature could be inferred directly from the scattering intensity using the state equation for a perfect gas. The temperature measurements also include the probability density functions at several locations.