Patent ID: 8687175

Claim:
A method of monitoring velocity of a fluid flow through a predetermined fluid flow space formed by a wall defining and extending in a fluid flow direction, the method comprising: supporting a fiber optic conductor on the wall, the fiber optic conductor having a flow measurement portion defining an elongated dimension extending across a portion of the fluid flow space and the elongated dimension extending transverse to the fluid flow direction for flexing in response to fluid flow against the flow measurement portion, the flow measurement portion including a Bragg grating having a characteristic optical wavelength; the fluid flow in the fluid flow space causing the measurement portion of the fiber optic conductor to flex in a direction transverse to the elongated dimension; supplying optical radiation to the fiber optic conductor, and the Bragg grating interacting with the supplied optical radiation; receiving optical radiation from the fiber optic conductor after the supplied optical radiation has passed through at least a portion of the measurement portion and has interacted with the supplied optical radiation; and analyzing the received optical radiation to produce a determination of a flow velocity of the fluid flow; wherein the fiber optic conductor extends within a hollow elongate conduit structure, the hollow conduit structure extending into the flow space from a location on the wall and back to the location on the wall in a generally circular loop, the generally circular loop defining a plane that extends transverse to the fluid flow direction, and the fluid flow passes through the loop transverse to the plane defined by the loop, the fluid flow causing the measurement portion of the fiber optic conductor to flex in the direction transverse to the plane defined by the loop, between a pair of locations on the loop where the fiber optic conductor extends outside of the conduit structure.