Burst-mode planar laser-induced fluorescence (PLIF) imaging of the OH radical is demonstrated in laminar and turbulent hydrogen-air diffusion flames with pulse repetition rates up to 50 kHz. Nearly 1 mJ/pulse at 313.526 nm is used to probe the OH P(2)(10) rotational transition in the (0,0) band of the A-X system. The UV radiation is generated by a high-speed-tunable, injection-seeded optical pa...

Planar Laser-Induced Fluorescence PLIF is employed to measure rotational temperatures at the nozzle exit of a free-piston shock tunnel. The ow is at approximately Mach 7 and chemical eeects have been reduced by using a nitrogen test gas and low total enthalpy 5 MJJkg. Vibrational freezing in the nozzle expansion has an appreciable effect on the nozzle-exit rotational temperature, and therefore ...

UV planar laser-induced fluorescence (PLIF) images of hot carbon dioxide (CO2) are obtained in a laminar flame (CH4/air) at high pressure (20 bar) with excitation wavelengths at 239.34 nm and 242.14 nm. Excitation wavelengths are chosen to minimize the contribution of nitric oxide and molecular oxygen LIF signals. Spectrally resolved single point measurements are used for correction of the rema...

We present the recent advances made in fiber-coupled laser-diagnostic methods that are being developed for practical combustion applications. In particular, we describe fiber-coupled, picosecond, coherent anti-Stokes Raman scattering (ps-CARS) spectroscopy, fiber-coupled, nanosecond, ultraviolet planar-laser-induced-fluorescence (ns-UVPLIF) spectroscopy, and fiber-coupled, particle-image veloci...

The successful development and optimization of fusion power sources will depend largely upon learning more about plasma turbulence and its relation to transport. Gaining a greater knowledge of plasma-edge turbulence is key, as the transport of particles near the plasma's edge has a profound effect on global plasma confinement. It is in this region that the boundary values for plasma temperature...

A preliminary combined experimental and computational investigation is conducted on the mixing characteristics of a strut-based hypermixer in a Mach 3 freestream. The hypermixing flow-field is generated by an injection pylon with expansive wedges to enhance the streamwise vorticity. Two different scalar visualization techniques are used to examine the underlying mixing processes. Planar laser s...

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...

BACKGROUND Degenerative disc disease is a common cause of chronic and disabling back pain that requires surgical intervention, posterolateral and posterior instrumental fixation (PLF), posterior lumber interbody fusion (PLIF) and transforaminal lumber interbody fusion (TLIF) are the techniques used to deal with such a problem. OBJECTIVE To compare the clinical and radiological outcome of the ...

This paper describes laser imaging experiments on steady, rotationally symmetric, laminar jets aimed at observation of the interface between an injected liquid and surrounding gas under subcritical, transcritical, supercritical conditions. A flow fluoroketone enters a chamber high pressure temperature nitrogen, allowing direct examination as it evolves with time (i.e., axial position in chamber...