Variable aperture orifice plate assembly

An orifice plate system adapted for fluid flow therethrough in a flow region extending along a flow axis and laterally bounded by a tubular inward facing surface from an upstream end to a downstream end of the flow region, comprising:

• A. a damper assembly adapted for disposition in the flow region along the fluid flow axis having a first side facing the upstream end and a second side opposite the first side and facing the downstream end, and defining an array of one or more adjustable cross-section area variable apertures characterized by an aggregate area Ao within the bounds of the inward facing surface and defining fluid flow paths therethrough between an upstream portion of the flow region between the first side and the upstream end and a downstream portion of the fluid region between the second side and the downstream end, wherein Ao is representative an aggregate of areas of cross-sections of the apertures of the array of apertures normal to fluid flow paths passing through the apertures,
• B. an upstream sensor adapted for sensing upstream pressure at an upstream pressure sense locus in an upstream portion of the flow region displaced distal in the direction of the flow axis from the first side,
• C. a downstream sensor adapted for sensing downstream pressure in at least one downstream pressure sense locus in a downstream portion of the flow region proximal in the direction of the flow axis to the second side and between perimeters of apertures of the array of apertures in a downstream portion of the flow region.
• D. a net pressure source assembly adapted to effect an adjustable net fluid pressure across an upstream point at or upstream of the upstream pressure sense locus and a downstream point at or downstream of the downstream pressure sense locus, in response to an applied net pressure control signal,
• E. an actuator assembly adapted to adjust the cross-section areas of respective variable apertures of the array in response to an applied damper area control signal, and
• F. a processor responsive to:
• i. the sensed upstream pressure and sensed downstream pressure to generate a pressure difference signal representative of a differential pressure ΔP along the flow axis across the damper assembly,
• ii. the net pressure source assembly to generate a net pressure control signal representative of a differential pressure across the upstream point and the downstream point,
• iii. the actuator assembly to generate an aperture signal representative of the area of the respective apertures normal to flow paths of fluid flowing therethrough,
• iv. the pressure difference signal, and the aperture signal to generate a damper area control signal, and apply the damper area control signal to the actuator assembly, and apply the net pressure control signal to the net pressure source assembly, all in a closed loop manner,
• whereby fluid flows from the upstream end, through the array of apertures characterized by aggregate area Ao normal to the flow therethrough, and to the downstream end wherein the fluid flowing between the array of apertures and the downstream end, is characterized by a corresponding array of vena contractae having an aggregate cross section area Ao normal to the fluid flow therethrough, where Ac<Ao, and Ao is less than the aggregate cross section area normal to fluid flow elsewhere between the array of apertures and the downstream end,
• thereby establishing a contraction coefficient C, wherein
• C
• =
• A
• c
• A
• o
• whereby the processor is responsive to contraction coefficient C, the aperture signal and the pressure signal, to regulate the variable apertures over time in a closed loop manner so that a set point is attained.

An orifice plate assembly disposed within an inward-facing tubular wall extending along a flow axis from an upstream end to a downstream end, comprising:

• A. a damper assembly traversing the inward-facing tubular wall and including downstream-facing surfaces defining an array of one or more adjustable cross section apertures defining a corresponding array of fluid flow paths therethrough,
• wherein the array of apertures is characterized by an aggregate area Ao corresponding to an aggregate of the aperture areas normal to the respective flow paths,
• B. at least one upstream pressure sensor adapted to determine total pressure at at least one upstream pressure sense locus upstream of the damper assembly wherein the upstream pressure sense locus is between and spaced apart from the array of apertures and the upstream end,
• C. at least one downstream pressure sensor adapted to determine static pressure at at least downstream pressure sense locus downstream of the damper assembly wherein the at least one downstream pressure sense loci are pneumatically coupled and extend from the downstream-facing surfaces defining the array of apertures and toward the downstream end,
• D. an actuator assembly adapted for adjustably controlling the aggregate area Ao, and
• E. a processor configured for feedback operation of the assembly in a closed-loop, to effect operation as an orifice plate,
• wherein processor is responsive to:
• i. the at least one upstream pressure sensor and the at least one downstream pressure sensor to determine differential pressure across the damper assembly, and
• ii. the actuator assembly to determine the aggregate area Ao of the respective apertures normal to the flow paths of fluid flowing therethrough, to control one or both of the differential pressure and the aggregate area Ao in a closed-loop manner so that fluid flowing between the array of apertures and the downstream end, is characterized by a corresponding array of vena contractae.

A method of characterizing an orifice plate assembly for a fluid of interest wherein the orifice plate assembly is adapted for disposition within an inward-facing tubular wall extending along a flow axis from an upstream end to a downstream end, and includes:

• A. a damper assembly traversing the inward-facing tubular wall and including downstream-facing surfaces defining an array of one or more adjustable cross section apertures defining a corresponding array of fluid flow paths therethrough, wherein the array of apertures is characterized by an aggregate area Ao corresponding to an aggregate of the aperture areas normal to the respective flow paths,
• B. at least one upstream pressure sensor adapted to determine total pressure at at least one upstream pressure sense locus upstream of the damper assembly wherein the upstream pressure sense locus is between and spaced apart from the array of apertures and the upstream end,
• C. at least one downstream pressure sensor adapted to determine static pressure at at least downstream pressure sense locus downstream of the damper assembly wherein the at least one downstream pressure sense loci are pneumatically coupled and extend from the downstream-facing surfaces defining the array of apertures and toward the downstream end,
• D. an actuator assembly adapted for adjustably controlling the aggregate area Ao, and
• E. a processor configured for feedback operation of the assembly in a closed-loop, to effect operation as an orifice plate,
• wherein processor is responsive to:
• i. the at least one upstream pressure sensor and the at least one downstream pressure sensor to determine differential pressure ΔP across the damper assembly, and
• ii. the actuator assembly to determine the aggregate area Ao of the respective apertures normal to the flow paths of fluid flowing therethrough,
• to control one or both of the differential pressure and the aggregate area Ao in a closed-loop manner so that fluid flowing between the array of apertures and the downstream end, is characterized by a corresponding array of vena contractae, whereby a set point for a parameter of interest in a predetermined range PIR is attained,
• comprising the steps of:
• (1) passing the fluid of interest through the orifice assembly from the upstream end to the downstream end, at a succession of n values of the parameter of interest in the predetermined range PIR, where n is an integer,
• (2) for each of the n values of the parameter of interest in the predetermined range PIR, selectively varying ΔP within a pressure range PR and Ao within an aperture range AR while maintaining the value of the parameter of interest constant, and determining a table of ki values for ΔP and Ij values for Ao, for combinations of the ki values and Ij values within their respective ranges PR and AR,
• whereby the values in the n tables characterize the parameter of interest over the ranges PIR, PR and AR.

A method of conforming a characteristic performance of a fluid assembly corresponding at least in part structurally to the orifice plate assembly of claim 96, including:

• A. a damper assembly structurally similar to the damping assembly of the orifice plate assembly of claim 96,
• B. an actuator assembly functionally similar to the damping assembly of the orifice plate assembly of claim 96,
• C. a processor configured for feedback operation of the fluid assembly to effect operation as an orifice plate,
• comprising the steps of:
• by the processor, executing instructions for controlling operation to selectively gain access to the n tables of claim 96 and, in response thereto, controlling one or both of the differential pressure and the aggregate area Ao of the fluid assembly to simulate corresponding activity of an orifice plate assembly of claim 96, thereby conforming characteristic performance of the fluid assembly to that of the orifice plate assembly of claim 96.

A fluid assembly for a fluid of interest wherein the fluid assembly is adapted for disposition within an inward-facing tubular wall extending along a flow axis from an upstream end to a downstream end, and includes:

• A. a damper assembly traversing the inward-facing tubular wall and including downstream-facing surfaces defining an array of one or more adjustable cross section apertures defining a corresponding array of fluid flow paths therethrough, wherein the array of apertures is characterized by an aggregate area Ao corresponding to an aggregate of the aperture areas normal to the respective flow paths,
• B. an actuator assembly adapted for adjustably controlling the aggregate area Ao, and
• C. a memory storing n differential pressure ΔP and aggregate area Ao data tables for an orifice plate assembly disposed within an inward-facing tubular wall extending along a flow axis from an upstream end to a downstream end, and comprising a damper assembly structurally similar to that of the fluid assembly, wherein the differential pressure ΔP and aggregate area Ao of the n data tables for the orifice plate assembly are obtained by
• a. passing the fluid of interest through the orifice plate assembly from the upstream end to the downstream end, at a succession of n values of a parameter of interest in the predetermined range PIR, where n is an integer,
• b. for each of the n values of the parameter of interest in the predetermined range PIR, selectively varying ΔP within a pressure range PR and Ao within an aperture range AR while maintaining the value of the parameter of interest constant, and determining a table of ki values for ΔP and Ij values for Ao, for combinations of the ki values and Ij values within their respective ranges PR and AR,
• wherein one or both of the differential pressure and the aggregate area Ao is controlled in a closed-loop manner so that fluid of interest flowing between the array of apertures and the downstream end of the orifice plate assembly, is characterized by a corresponding array of vena contractae, whereby a set point for a parameter of interest in a predetermined range PIR is attained, whereby the values in the n data tables characterize the parameter of interest over the ranges PIR, PR and AR for the fluid of interest, and
• D. a processor configured to effect operation of the fluid assembly as an orifice plate, wherein processor includes instructions for control of its operation to selectively gain access to the n data tables of the memory and, in response thereto, control one or both of the differential pressure and the aggregate area Ao of the fluid assembly so that fluid of interest flowing through the fluid assembly between the array of apertures and the downstream end, is characterized by a corresponding array of vena contractae, whereby a set point for a parameter of interest in a predetermined range PIR is attained.