Hybrid constraint multi-line absorption spectroscopy for non-uniform thermochemical measurements in axisymmetric laminar and jet flames

We propose a novel strategy for the accurate determination of non-uniform thermochemical distributions in axisymmetric flames using line-of-sight laser absorption spectroscopy with constraints hybrid information. In this method, computational fluid dynamics (CFD) simulation or other diagnostic method (e.g., thermocouple measurement) is used to qualitatively characterize properties, whereas kinetic modelling, chemical equilibrium calculation and measurement are constrain range unknown parameters. Experimental demonstrations were firstly performed standard laminar CH4/air premixed flame stabilized on McKenna burner at different equivalence ratios (Φ = 0.8-1.2). With proper constraints, multiple solutions avoided, deviation convergence time can be simultaneously reduced comparing conventional method. For further demonstration, was then applied turbulent jet recover significant gradient without need tomographic reconstruction techniques.