Broadband ultrafast-laser-absorption spectroscopy for multi-hydrocarbon measurements near 3.3 µm in flames.

This paper presents the development and application of a broadband ultrafast-laser-absorption-spectroscopy (ULAS) technique operating in the mid-infrared for simultaneous measurements of temperature, methane ( ), and propane ( ) mole fractions. Single-shot measurements targeting the C-H stretch fundamental vibration bands of and near 3.3 µm were acquired in both a heated gas cell up to ≈650 and laminar diffusion flames at 5 kHz.

Characterization of non-Boltzmann CN X2Σ+ behind shock waves in CH4-N2 via broadband ultraviolet femtosecond absorption spectroscopy.

This article describes the temporal evolution of rotationally and vibrationally non-Boltzmann CN X2Σ+ formed behind reflected shock waves in N2-CH4 mixtures at conditions relevant to atmospheric entry into Titan. A novel ultrafast (i.e.

Ultrafast-laser-absorption spectroscopy in the mid-infrared for single-shot, calibration-free temperature and species measurements in low- and high-pressure combustion gases.

This manuscript presents an ultrafast-laser-absorption-spectroscopy (ULAS) diagnostic capable of providing calibration-free, single-shot measurements of temperature and CO at 5 kHz in combustion gases at low and high pressures. Additionally, this diagnostic was extended to provide 1D, single-shot measurements of temperature and CO in a propellant flame. A detailed description of the spectral-fitting routine, data-processing procedures, and determination of the instrument response function are also presented.

Spectrally resolved, 1D, mid-infrared imaging of temperature, CO, and HCl in propellant flames.

This work presents a high-speed, spectrally resolved, mid-infrared imaging diagnostic for providing 1D measurements of gas temperature and relative mole fraction of ${{\rm{CO}}_2}$ and HCl in flames. An imaging spectrometer and a high-speed mid-infrared camera were used to provide 1D measurements of ${{\rm{CO}}_2}$ and HCl emission spectra from 2386 to ${{2402}}\;{{\rm{cm}}^{- 1}}$ with a spectral resolution of ${0.46}\;{{\rm{cm}}^{- 1}}$, and simulated emission spectra were least-squares fit to the data to determine the aforementioned gas properties.

2D mid-infrared laser-absorption imaging for tomographic reconstruction of temperature and carbon monoxide in laminar flames.

This manuscript presents the design and initial application of a mid-infrared laser-absorption-imaging (LAI) technique for two-dimensional (2D) measurements and tomographic reconstruction of gas temperature and CO in laminar flames. In this technique, the output beam from a quantum-cascade laser (QCL) is expanded, passed through the test gas, and imaged in 2D using a high-speed mid-infrared camera. The wavelength of the QCL is scanned across the P(0,20) and P(1,14) transitions of CO near 4.

Design and application of a high-pressure combustion chamber for studying propellant flames with laser diagnostics.

This manuscript presents the design and initial application of a high-pressure combustion chamber (HPCC). The HPCC exhibits several unique design attributes to enable high-fidelity studies of propellant-combustion physics at high pressures. The HPCC employs a flangeless and weldless design to provide a compact, easy to access, and relatively light weight (for its size and pressure capability) test chamber.