Method and apparatus for measuring operational gas turbine engine housing displacement and temperature by a distributed fiber optic sensing system utilizing optical frequency domain reflectometry

摘要

Operational gas turbine engine housing or casing dynamic strain, temporary or permanent displacement and/or temperature is measured by a distributed fiber optic sensing system (DFOSS) utilizing optical frequency domain reflectometry (OFDR) that is coupled to the turbine engine housing. The DFOSS/OFDR system measures localized variances in strain along the length of an optical fiber (OF), which are correlated with turbine engine housing displacement. Temperature influence on the measured localized strain variances is accounted for by obtaining temperature information from an another measurement system or by taking the same type OFDR measurements on unrestrained optical fiber (OF) and deriving compensated strain measurements that are not temperature influenced. The derived strain measurements along the DFOSS are correlated with housing displacement. Other embodiments include separate displacement measuring modules, each including DFOSS optical fibers, coupled along the engine housing.

主权项

1. A method for measuring operational gas turbine engine housing displacement/temperature, comprising:
coupling a distributed fiber optic sensing system (DFOSS) to a gas turbine engine housing and measuring optical fiber (OF) temperature influenced strain along the length of the OF by optical frequency domain reflectometry (OFDR) during engine operation; coupling a temperature sensor to the gas turbine housing and measuring temperature during engine operation; separating temperature influence from the DFOSS temperature influenced strain measurements with the temperature sensor temperature measurements and deriving compensated strain measurements; and correlating the derived strain measurements along the DFOSS with housing displacement of the gas turbine engine.