アブレーションセンサ

抄録

Operational principles and operational characteristics of an ablation sensor named ASU (Ablation Sensor Unit), which has been recently developed for obtaining the in-flight thermal response of ablative heatshields such as charring, surface recession, and temperature, are described. ASU is made of char sensor and surface recession sensor. The char sensor is designed to measure char depth in thermally degraded ablative heatshield using an electrical circuit. The surface recession sensor detects the arrival time of recessed material surface at a given depth by measuring the transition of thermal emission from ablative material to shock layer using an optical fiber. The measured intensity of thermal emission is concurrently used to deduce temperature based on a two-color radiation thermometry principle. A typical example set of thermal response data obtained in an aerodynamic heating environment produced in an arcjet wind tunnel is presented, demonstrating the ablation detection with temporal and spatial resolution by ASU.