Filtered Rayleigh scattering measurements of temperature in cellular tubular flames

Steady, premixed tubular flames that produce cellular flames due to low Lewis number can assist in validating diffusional properties for numerical models. The lean hydrogen-air mixture creates conditions of low Lewis number that have shown to result in cellular flames inside tubular burners due to preferential diffusion. Filtered Rayleigh scattering (FRS) is used to achieve two-dimensional temperature measurements across perpendicular planes in the cellular tubular flame. Different FRS strategies, a pulsed Nd:YAG laser with and without Fabry–Perot etalon as well as a continuous wave laser, are contrasted for consistency and uncertainty in the tubular flame measurements. The FRS temperature profiles are found to be consistent with previous spontaneous Raman scattering temperature measurements but differ from previous direct numerical simulation results. Graphic abstract