Optical fiber flow velocity and flow direction measuring method based on constant laser and temperature distribution

The invention provides an optical fiber flow velocity and flow direction measurement method based on constant laser and temperature distribution. The method comprises the following steps: S1, arranging a measurement device; the measuring device comprises an optical fiber, a heat source rod and a plurality of FBG sensors. S2, heating a heat source rod by adopting constant laser; s3, calculating the temperature change delta T (r, theta) at one FBG sensor, carrying out nondimensionalization on the temperature change delta T (r, theta) to obtain a dimensionless temperature change delta T '(r', theta), and calculating the liquid flow velocity v according to the delta T '(r', theta); and S4, the temperature change delta Ti of the FBG sensors is calculated, the liquid flow direction theta flow is obtained through combination, and i is the number of the FBG sensors. The flow velocity and the flow direction are measured through optical fiber sensing, and compared with an electric sensing measurement method, the method