Advancements in Tunable Diode Laser Absorption Spectroscopy for Hypersonic Wind Tunnel Testing

Hypersonic wind tunnels play a crucial role in aerospace research, and tunable diode laser absorption spectroscopy (TDLAS) serves as an invaluable diagnostic method in this field. TDLAS offers no-contact, highly sensitive, and multiparameter measurement capabilities coupled with a simple structure, cost-effectiveness, and high spatiotemporal resolution. This study introduces the measurement principle and typical optical design of TDLAS, highlighting its widespread use for measuring parameters such as temperature, component concentration, and airflow velocity in extreme environments such as hypersonic wind tunnels. Furthermore, this study provides an overview of recent applications of TDLAS in hypersonic wind tunnel flow field diagnosis globally. Additionally, it summarizes the current development status and challenges of TDLAS in hypersonic wind tunnel flow field diagnosis in China. It concludes with a brief outlook on the prospective development of TDLAS flow field diagnosis technology in hypersonic wind tunnels, offering valuable insights for future advancements and related experiments in this domain.