Differential pressure flow sensor
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorMichael A. Deeds
Life of this patent
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Abstract
The fluid flow meter of the present invention includes a ramp inclined to the surface of a vessel so as to form a recess in the surface. A dynamic port surface extends from the lower end of the ramp to the surface of the vessel. A dynamic port is formed in the surface of the vessel, and a static port is formed in the ramp. The differential pressure between the dynamic and static ports is measured and is related to the flow velocity of fluid over the surface. The inventive flow meter has advantages of reduced drag, reduced likelihood of fouling and reduced likelihood of impact damage compared to conventional flow meters.
Claims25
A fluid flow meter in the surface of a vessel, comprising:
- a ramp connected to and extending longitudinally from a surface of a vessel exposed to fluid flow at a first end of the ramp to an opposite end of the ramp, said ramp inclined at a first angle to the surface to form a recess in the surface of the vessel;
- a port member having a surface extending from said opposite end of the ramp, said dynamic port surface being oriented at a second angle to said ramp, wherein said second angle comprises less than about 180 degrees between said ramp and said surface, said surface having a dynamic port formed therein, the axis of said dynamic port oriented approximately parallel to said ramp;
- and
- a pressure measurement device connected to the dynamic port, for measuring the dynamic pressure caused by a flow of fluid in a direction roughly parallel to the surface of the vessel exposed to fluid flow.
A fluid flow meter for installation in a vessel, comprising:
- a housing for installing in a complementary hole in the vessel, said housing comprising:
- a top surface of curvature matching the curvature of a surface of a vessel exposed to fluid flow;
- a ramp connected to and extending from said top surface at a first end of the ramp longitudinally to an opposite end of the ramp, said ramp inclined at a first angle to the top surface to form a recess in the top surface;
- a port member having a surface extending from said opposite end of the ramp, said surface being oriented at a second angle to said ramp, said second angle comprises less than about 180 degrees between said ramp and said surface, said surface having a dynamic port formed therein, the axis of said dynamic port oriented approximately parallel to said ramp;
- a static port formed in the ramp;
- and
- a differential pressure sensor connected to said dynamic and static ports.
A method of measuring fluid flow velocity above the boundary layer and across the surface of an object, comprising the steps of:
- providing a ramp connected to a surface of an object exposed to fluid flow inclined to the surface so as to form a recess;
- providing a dynamic port in a port member having a surface extending from the recessed end of the ramp at an angle comprising less than about 180 degrees between said ramp and said surface;
- determining a calibration of the dynamic pressure in the dynamic port as a function of known fluid flow velocity;
- and
- interpolating the value of an unknown fluid flow velocity from said calibration.
A method of measuring fluid flow velocity above the boundary layer and across the surface of an object, comprising the steps of:
- providing a ramp connected to a surface of an object exposed to fluid flow inclined to the surface so as to form a recess;
- providing a dynamic port in a port member having a surface extending from the recessed end of the ramp at an angle comprising less than about 180 degrees between said ramp and said surface;
- providing a static port in the ramp;
- determining a calibration of the differential pressure between the static and dynamic pressures as a function of known fluid flow velocity;
- and
- interpolating the value of an unknown fluid velocity from said calibration of the differential pressure.
Dependencies are inferred from the claim text.