Sonar circumferential flow conditioner

A method of detecting pressure variations within a fluid that is flowing in a conduit in order to measure a velocity of the fluid, comprising:

• introducing the pressure variations into the fluid with a backward-facing step formed by an enlargement in an inner diameter of the conduit in a direction of fluid flow;
• reducing turbulence in the fluid with a converging inner diameter portion of the conduit prior to introducing the pressure variations, wherein the inner diameter is gradually reduced from a primary diameter ahead of the converging inner diameter portion to a first diameter prior to the enlargement at the step to a second diameter that is smaller than the primary diameter;
• sensing the pressure variations with an array of pressure sensors at spaced locations along a length of the conduit where the inner diameter remains enlarged past the step;
• and
• calculating the velocity of the fluid based on the pressure variations that are sensed.

A system for detecting pressure variations within a fluid for measuring flow of the fluid, comprising:

• a conduit containing the fluid, wherein a first section of the conduit is located between a second section of the conduit and a converging inner diameter portion of the conduit that gradually reduces a primary inner diameter of the conduit to a first inner diameter at the first section, which first section transitions to the second section that has a second inner diameter larger than the first inner diameter;
• an array of pressure sensors to sense the pressure variations, wherein the sensors are spaced along a length of the second section with the second inner diameter;
• and
• signal interface circuitry configured to measure a velocity of the fluid based on signals from the array of pressure sensors.