CARS temperature measurement in a LOX/CH₄ spray flame

Abstract

Coherent anti-Stokes Raman scattering (CARS) spectroscopy has been used to investigate cryogenic liquid oxygen/gaseous methane (LOX/CH 4 ) flames on a medium-size test facility at a pressure of 0.24 MPa and mass flow of 0.025 kg/s. Single-shot, broadband CARS spectra with simultaneous detection of the Q-branches of hydrogen and water molecules were recorded with good signal-to-noise ratio. Temperature was deduced from the H 2 and H 2 O CARS profiles. The spatial temperature distribution in a comparatively harsh environment has been measured successfully. The measurements took place in the windowed combustion chamber of the DLR M3 test facility, aiming to provide data for validation of rocket combustor modeling. Copyright

Recent advances in linear and nonlinear Raman spectroscopy. Part V

“…CARS spectroscopy was used by Fabelinksy et al to investigate cryogenic liquid oxygen/gaseous methane flames on a medium-size test facility at a pressure of 0.24 MPa and mass flow of 0.025 kg s À1 . [87] Single-shot, broadband (BB) CARS spectra with simultaneous detection of the Q-branches of hydrogen and water molecules were recorded with good signal-to-noise ratio. A two-beam multiplexed CARS microscopy setup is demonstrated by using a broadband (BB) Ti : sapphire oscillator without using any specialty fibers.…”

Temperature fluctuations in turbulent flame measured using coherent anti-Stokes Raman scattering

“…Some examples of recent practical applications of CARS techniques using nanosecond pulse pump lasers, as well as references to publications describing the advantages, peculiarities, and methods of implementation of the techniques, are presented in [1,2] and in the review [3].…”

“…Fluctuations of local tem perature are measured in a turbulent diffusion flame of decane-air mixture in a laboratory burner. The CARS diagnostic system incorporated a fre quency doubled pulse repetitive Nd 3+ :YAG laser (LS 2137/2, Lotis TII, 10 Hz, ~10 ns, 532 nm), a modeless broadband dye laser [1] (Cluster Ltd., 607 nm, spectral width ~200 cm -1 ); a set of mirrors and lenses; a spectrograph (Cluster Ltd., 1200 lines/mm, focal length 1 m) equipped with a gated, image inten sified optical multichannel analyzer (PI MAX, Prin ston Instruments); a synchronization pulse generator; a computer. The energy of pump radiation pulses was 20 mJ (532 nm) and 10 mJ (607 nm).…”

Advanced Laser-Based Techniques for Gas-Phase Diagnostics in Combustion and Aerospace Engineering

“…[143][144][145] Clauss and collaborators applied hydrogen CARS thermometry to combustion systems of relevance to rocket engines. For example, they studied cryogenic liquid oxygen (LOX) and gaseous oxygen-fed hydrogen [146][147][148] and hydrocarbon 147,149,150 flames operated under rather extreme conditions, i.e., pressures as high as 20 MPa and temperatures as high as 3000 K. Similar temperatures were measured in the jet flame of a staged oxy-fuel burner of a large-scale industrial furnace fueled with natural gas. 151 Kampmann et al 152 used vibrational CARS in a highly turbulent swirl flame.…”