Fluid turbulence monitoring by means of FBG mesh

Single-phase flow turbulence monitoring by means of the utilization of an optical fiber Bragg grating (FBG) mesh is presented in this work. Present device is immune to electromagnetic interferences and independent of the fluid dielectric constant or pipe transparency. The kinetic energy of the flow produces a wavelength shift associated to the strain, which is the basis of the detection mechanism. Spatial resolution inside the pipes is obtained by arranging the FBGs in a 8×8 matrix shape with a total of 16 FBGs multiplexed within the same single mode fiber (SMF), which reduces considerably the size and connections of the device. The results show differentiated patterns as a function of time and flow speed, which can be directly associated to velocity distributions inside the tube. Different regions can be differentiated as a function of the force induced strain: core, annular and wall regions.