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US 6,553,844 B2Granted
Property-independent volumetric flowmeter and sonic velocimeter
AssigneemetaSENSORS, Inc.
InventorTadeusz M. Drzewiecki
Life of this patent
Estimating the term…
Abstract
A single fluidic feedback oscillator incorporates two independent time event measurement means, resulting in a highly accurate volumetric flowmeter that is independent of the properties and composition of the flowing fluid. Under certain circumstances, when the relationship between speed of sound and specific heat of the fluid is generally known, the oscillator provides for a highly accurate sonic velocimeter and consequently can be used as a calorimeter. The main components of the invention are a fluidic amplifier oscillator, and two sets of sensors located at separate locations in either the feedback channels of the oscillator or in the oscillating jet flow region.
Claims29
Apparatus for determining flow rate of a flowing fluid independently of properties and composition of the fluid and simultaneously for determining the speed of sound in the fluid, comprising:
- a fluidic feedback oscillator including nozzle means for establishing an oscillating stream of the fluid, input means for changing directional movement of said stream of fluid, output means located a known distance from said nozzle means for receiving said stream as a function of stream directional movement, and feedback means of known feedback length for directing at least a portion of the received stream from said output means to said input means to create oscillatory directional movement of said stream;
- first and second independent sensor means for monitoring oscillation of the fluid stream and providing respective first and second sensor signals representing specified stream oscillation characteristics, said first sensor means being positioned at a first location in said fluid stream, said second sensor means being positioned at a second location in said fluid stream spaced downstream from said first location by a known sensor spacing;
- and
- processor means comprising:
- means responsive to said first and second sensor signals for computing the period of oscillation of said stream and computing a sensing time delay between sensing of said specified stream oscillation characteristics by the first sensor and sensing of the same specified oscillation characteristics by said second sensor;
- means responsive to said computed sensing time delay and said known sensor spacing for computing the propagation velocity of said fluid stream in said oscillator;
- means responsive to said computed propagation velocity and said known feedback length for computing the feedback time delay through said feedback means;
- means for computing the flow time delay of the stream between said nozzle means and said output means by subtracting said computed feedback time delay from said computed period of oscillation;
- and
- means for computing the flow velocity of said stream by dividing said known distance by said computed flow time delay.
7 more elements
A method for determining flow rate of a flowing fluid independently of properties and composition of the fluid and providing the capability for simultaneously determining the speed of sound in the fluid, said method comprising the steps of:
- (a) in a fluidic feedback oscillator:
- (a.1) establishing from a nozzle an oscillating stream of the fluid,
- (a.2) with input means, changing directional movement of said stream of fluid,
- (a.3) at output means located a known distance from said nozzle, receiving said stream as a function of stream directional movement, and
- (a.4) directing at least a portion of the received stream from said output means through a feedback channel of known length to said input means to create oscillatory directional movement of said stream;
- (b) monitoring oscillation of the fluid stream with first and second independent sensor means, spaced in said oscillator by a known sensor spacing, and providing respective first and second sensor signals representing specified stream oscillation characteristics;
- (c) in response to said first and second sensor signals:
- (c.1) computing the period of oscillation of said stream;
- (c.2) computing a sensing time delay between sensing of said specified stream oscillation characteristics by the first sensor and sensing of the same specified oscillation characteristics by said second sensor;
- (c.3) from said computed sensing time delay and said known sensor spacing, computing the propagation velocity of said fluid stream in said oscillator;
- (c.4) from said computed propagation velocity and said known feedback length, computing the feedback time delay through said feedback means;
- (c.5) computing the flow time delay of the stream between said nozzle means and said output means by subtracting said computed feedback time delay from said computed period of oscillation;
- and
- (c.6) computing the flow velocity of said stream by dividing said known distance by said computed flow time delay.
11 more elements
Apparatus for determining flow rate of a flowing fluid independently of properties and composition of the fluid and simultaneously determining the speed of sound in the fluid, comprising:
- a fluidic feedback oscillator including nozzle means for establishing an oscillating stream of the fluid, input means for changing directional movement of said stream of fluid, output means located a known distance from said nozzle means for receiving said stream as a function of stream directional movement, and feedback means of known feedback length substantially greater than said known distance for directing at least a portion of the received stream from said output means to said input means to create oscillatory directional movement of said stream;
- first and second independent sensor means for monitoring oscillation of the fluid stream and providing respective first and second sensor signals representing specified stream oscillation characteristics, said second sensor means being spaced downstream from said first sensor means in said oscillator by a known sensor spacing;
- processor means comprising:
- means responsive to said first and second sensor signals for computing the period of oscillation of said stream and computing a sensing time delay between sensing of said specified stream oscillation characteristics by the first sensor and sensing of the same specified oscillation characteristics by said second sensor;
- and
- means for computing the flow velocity of said stream by multiplying said known sensor spacing by said computed sensing time delay.
3 more elements
A method for determining flow rate of a flowing fluid independently of properties and composition of the fluid and providing the capability for simultaneously determining the speed of sound in the fluid, said method comprising the steps of:
- (a) in a fluidic feedback oscillator:
- (a.1) establishing from a nozzle an oscillating stream of the fluid,
- (a.2) with input means, changing directional movement of said stream of fluid,
- (a.3) at output means located a known distance from said nozzle, receiving said stream as a function of stream directional movement, and
- (a.4) directing at least a portion of the received stream from said output means through a feedback channel of known length to said input means to create oscillatory directional movement of said stream;
- (b) monitoring oscillation of the fluid stream with first and second independent sensor means, spaced from one another along said stream in said oscillator by a known sensor spacing, and providing respective first and second sensor signals representing specified stream oscillation characteristics;
- (c) in response to said first and second sensor signals:
- (c.1) computing the period of oscillation of said stream;
- and
- (c.2) computing a sensing time delay between sensing of said specified stream oscillation characteristics by the first sensor and sensing of the same specified oscillation characteristics by said second sensor;
- and
- (d) computing the flow velocity of said stream by multiplying said known sensor spacing by said computed sensing time delay.
9 more elements
Apparatus for determining flow rate of a flowing fluid independently of properties and composition of the fluid comprising:
- a fluidic feedback oscillator including nozzle means for establishing an oscillating stream of the fluid, input means for changing directional movement of said stream of fluid, output means located a known distance from said nozzle means for receiving said stream as a function of stream directional movement, and feedback means of known feedback length for directing at least a portion of the received stream from said output means to said input means to create oscillatory directional movement of said stream;
- first and second independent sensor means for monitoring oscillation of the fluid stream and providing respective first and second sensor signals representing specified stream oscillation characteristics, said first sensor means being positioned at a first location in said fluid stream, said second sensor means being positioned at a second location in said fluid stream spaced downstream from said first location by a known sensor spacing;
- and
- processor means responsive to said first and second sensor signals for computing the flow rate of said stream.
1 more element
A method for detennining flow rate of a flowing fluid independently of properties and composition of the fluid comprising:
- establishing an oscillating fluid stream;
- monitoring oscillation of the fluid stream with first and second independent sensor means spaced in said oscillator by a known sensor spacing along said stream, and providing respective first and second sensor signals representing specified stream oscillation characteristics;
- in response to said first and second sensor signals;
- computing the flow rate of said stream.
1 more element
Dependencies are inferred from the claim text.