Algebraic tomographic reconstruction of two-dimensional gas temperature based on tunable diode laser absorption spectroscopy

Based on tunable diode laser absorption spectroscopy, the combustion gas temperature distribution was reconstructed using the algebraic iterative reconstruction technique. The effects of the projected angle and number of rays on the temperature reconstruction results for both fan beam and parallel beam were investigated. The flow field information was shown in detail. The reconstruction quality increased with increased ray number for both parallel- and fan-beam projections. The trend tended to be smooth when the total number of beams exceeded 100. A virtual ray method combined with the reconstruction algorithms was proposed. The virtual ray method is effective to improve the accuracy of reconstruction results for the symmetric and non-axisymmetric temperature distributions. Moreover, the temperature reconstruction of an infrared gas-field furnace is demonstrated, showing the virtual ray method can be applied to the combustion diagnostics.