High-speed OH*Luminosity 059Schlieren + single-shot 355 LIFSoot incandescence
CameraPhantom + double intensifierPhantom v7.1Photron SA-X2Phantom v7.1
Lens f, f/#105 mm, f/4.550 mm, f/1.285 mm, f/2.850 mm, f/16 – check –
Filter center, fwhm310nm, 10 nm<600 nm628 nm, 32 nm<600 nm
Lighting635 nm LED, 1 µs pulse, 355 nm YAG for LIF
Frame period [µs]50506.7?
Exp. time [µs]2462?
Movie: Play or right-click to downloadSchlieren and single-shot 355 LIF;
Description310 nm natural emission. Dominated by OH* chemiluminescence near the lift-off length, but includes some soot incandescence contribution downstream. Flame stabilizes and moves back to the injector after the end of injection. Blue border is 50% of OH chemiluminescence threshold. Movie obtained simultaneously (same injection) as the <600 nm luminosity (at right).Combustion chemiluminescence and soot luminosity are visible from natural emission. Soot luminosity background is dynamically corrected. Flame stabilizes and moves back to the injector after the end of injection. Blue border is 50% of high-temperature chemiluminescence threshold.The coincidence of formaldehyde (CH2O) planar laser-induced fluorescence (PLIF) imaging is compared to the “softening” of refractive index gradients in the schlieren imaging during the low-temperature ignition event.
ReferencesSAE 2012-01-1239; Bardi, 2012;Skeen, 2014;SAE 2014-01-1252
Additional filesTime record of 310-nm lift-off from movie above
Liftoff vs time (310 nm)
Time record of <600 nm luminosity lift-off from movie above
Liftoff vs time (<600 nm)