ADDRESSED FIBER BRAGG GRATINGS FOR SHOCK WAVE FRONT VELOCITY CONTROL IN PIPELINES

Abstract

The article presents a low-sensor radio-photon system based on addressable fiber Bragg structures (AFBS) for real-time control of the shock wave velocity in a pipeline. This system is devoid of disadvantages caused by the use in similar systems of expensive optoelectronic interrogators and broadband direct video pulse detectors corresponding to the annular effect of a shock wave on the pipe deformation in the sensor installation zone, as a rule, a fiber Bragg grating (FBG). Recommendations for choosing the method of measuring the speed - the basic one, the design of the sensor - loop-shaped, as the most rational with the possibility of simple installation, are determined, the advantages of replacing the FBG with the FBG with a phase pi-shift or AFBS are discussed. A block diagram of the system with measurements on three bases has been developed. It is shown that when using AGBS, the achieved error in measuring pressure and time is 0.01%, and in terms of velocity 0.08 m/s. In addition, an analysis is made of the applicability of the considered methods and means for solving problems of front speed control under conditions of noise, acoustic and temperature instabilities, as well as control of pressure generated by a shock wave.