4. Laser and optical interferometry

K.A.Vereschagin, V.V. Smirnov, O.M. Stel’makh, V.I. Fabelinsky
General Physics Institute, IOFAN, Russia

Express CARS thermometry of hydrocarbon combustion at high pressure

We demonstrate the feasibility of single laser shot CARS thermometry with simultaneous measurement of intensities of hydrogen Q-branch lines and their line widths in a pulsed CH4/O2 combustion chamber operating at 20 MPa pressure and 3000 K temperature – the parameters that are typical for full-scale rocket engines. The measurements were done by means of a spectrograph combined with an interferometer having orthogonal directions of dispersions. This approach allows correct temperature evaluation that takes into account directly measured line widths.
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