Conserved scalar fluxes measured in a turbulent nonpremixed flame by combined laser Doppler velocimetry and laser Raman scattering

Laser Doppler Velocimetry

Thermographic laser Doppler velocimetry.

We propose a point measurement technique for simultaneous gas temperature and velocity measurement based on thermographic phosphor particles dispersed in the fluid. The flow velocity is determined from the frequency of light scattered by BaMgAl10O17:Eu2+ phosphor particles traversing the fringes like in conventional laser Doppler velocimetry. Flow temperatures are derived using a two-color rati...

Simultaneous CH planar laser-induced fluorescence and particle imaging velocimetry in turbulent nonpremixed flames

We report the simultaneous measurement of the flamefront location, using single-shot CH planar laserinduced fluorescence (PLIF), and the velocity field, using two-color digital particle imaging velocimetry (PIV), in nonpremixed turbulent flames. To minimize the influence of particle scattering on the CH PLIF images, we pump a CH B-X(0,0) transition at 390 nm and detect A-X fluorescence at 420–4...

Flow tracing fidelity of scattering aerosol in laser Doppler velocimetry.

An experimental method for the determination of the flow-tracing fidelity of a scattering aerosol used in laser Doppler velocimeters was developed with particular reference to the subsonic turbulence measurements. The method employs the measurement of the dynamic response of a flow-seeding aerosol excited by acoustic waves. The amplitude and frequency of excitation were controlled in order to s...

Diffractive beam splitter for laser Doppler velocimetry.

A miniaturized sensor head for the optical measurement of velocities of fluids based on laser Doppler velocimetry is demonstrated. Holographic optical elements mounted on a glass substrate are used for beam splitting and deflection. Volume holograms in dichromated gelatin exhibit good optical efficiency (75% transmission of a cascade of two holographic optical elements). With diffractive device...