Simultaneous measurement of two-dimensional temperature and velocity fields in high-temperature gas flow based on laser-induced phosphorescence

Simultaneous measurement of temperature and velocity fields in high-temperature gas flows traditionally necessitates two separate diagnostic systems with distinct laser sources, posing limitations for practical application in harsh environments. This paper proposes a novel laser-induced phosphorescence (LIP) method for simultaneously measuring the two-dimensional (2D) temperature and velocity fields utilizing one individual diagnostic system. The phosphorescent particles employed act as both temperature-sensitive indicators and flow tracers. With the phosphorescent particle emission properties systematically characterized, the optimal spectral bands for the intensity-ratio thermometry and the key parameters for the phosphorescent particle image velocimetry are determined. Further, an LIP-based measurement system is developed and implemented for the simultaneous 2D diagnostics in high-temperature gas flow. Experimental validation is performed through measuring the 2D temperature and velocity fields at the outlet of a turbine blade cascade. The obtained results demonstrate that the developed system achieves an average relative temperature measurement error of 0.87% with a standard deviation of 0.96% from 300 to 673 K. The average relative velocity field measurement error is 1.71% with a standard deviation of 2.74% when the velocity is less than 28 m/s. These results validate that the proposed method is feasible for the simultaneous temperature and velocity measurement of high-temperature gas flow.