Flow sensing in subterranean wells

A method of measuring flow rate in a subterranean well, the method comprising:

• detecting optical scattering in an optical waveguide positioned in the well;
• flowing fluid transversely across each chamber of a multi-chamber emitter positioned within the well simultaneously to produce vibration at a resonance frequency of a first chamber of the multi-chamber emitter, wherein a length of each chamber is uniform and a cross-sectional area of each chamber is different than the remaining chambers, and the chamber of the multi-chamber emitter that produces the resonance frequency vibration varies based on a flow rate of the flow across the multi-chamber emitter;
• the optical scattering varying in response to the vibration produced by the emitter;
• and
• determining a flow rate of the fluid based on the variation of the optical scattering.

A well system, comprising:

• at least one tubular string positioned in a wellbore;
• multiple locations at which fluid flows between an interior and an exterior of the tubular string;
• multiple multi-chamber emitters, each multi-chamber emitter producing vibration at a resonance frequency of a chamber of the respective multi-chamber emitter in response to a transverse flow across each chamber of the respective multi-chamber emitter simultaneously, wherein the respective chambers of each multi-chamber emitter having a uniform length and a cross-sectional area that is different than the remaining chambers, and the chamber of each multi-chamber emitter that produces the resonance frequency vibration varies based on a flow rate of the flow across the respective multi-chamber emitter;
• and
• an optical waveguide in which optical scatter varies in response to the resonance frequency vibrations.