Three-dimensional laser absorption spectroscopy velocimetry for high-speed flow diagnosis

This work presents a laser absorption spectroscopy-based three-dimensional velocity measurement technique for non-uniform high-speed flow diagnosis. Compared with the extra particle-based velocimetry methods, the developed technique avoids the issues raised by adding solid particles, through utilizing the Doppler shifts of absorption lines induced by the interaction between multi-angled laser beams and the target molecules. Numerical verification is carried out by reconstructing the 3D velocity distribution in a simulated scramjet combustor. The results successfully demonstrate the feasibility of the implemented technique, in practical strong-noise environment and high-speed status (up to 1100 m/s), potentially enabling applications in harsh and extreme working conditions.