Asymmetric fluid flow device

A fluid flow assembly for disposition along a central fluid flow path extending along a fluid flow axis and defining a flow region bounded by an inward-facing surface extending along the fluid flow axis from an upstream end to a downstream end, comprising:

• A. a plurality of damper blades disposed within the flow region, including:
• i. a first end blade characterized by a blade area A1, and
• a. extending from a first end blade axis extending transverse to the flow axis and across the flow region, to a first end blade perimeter section opposite the first blade axis, wherein at least a portion of the perimeter section matches in shape a corresponding portion of the inward facing surface, and
• b. adapted for pivotal motion at angle ϕ1 about the first end blade axis from a closed position whereby the matching portions of the first end blade perimeter section and inward facing wall are adjacent, thereby blocking fluid flow past the perimeter section of the first end blade along the flow path to an open position angularly offset therefrom,
• wherein the matching in shape portion of the perimeter section of the first end blade
• and the matching in shape portion of the inward facing surface opposite thereto define a first adjustable variable aperture through which at least a portion of the flow path passes when ϕ1 is offset from the closed position, and wherein the cross section area of fluid flow through the first adjustable variable aperture normal to the flow is Ao1,
• ii. a second end blade characterized by a blade area A2, and
• a. extending from a second end blade axis parallel to the first end blade axis, and extending transverse to the flow axis and across the flow region, to a second end blade perimeter section opposite the second blade axis wherein at least a portion of the perimeter section matches in shape a corresponding portion of the inward facing surface, and
• b. adapted for pivotal motion at angle ϕ2 about the second end blade axis wherein the second end blade axis extends across the second end blade and transverse to the flow path from a closed position whereby the matching portions of the second end blade perimeter section and inward facing wall are adjacent, thereby blocking fluid flow past the perimeter section of the second end blade along the flow path, to an open position angularly offset therefrom,
• wherein the matching in shape portion of the perimeter section of the second end blade and the matching in shape portion of the inward facing surface opposite thereto define a second adjustable variable aperture through which at least a portion of the flow path passes when ϕ2 is offset from the closed position, and wherein the cross section area of fluid flow through the second adjustable variable aperture normal to the flow is Ao2, and
• B. an actuator assembly including a plurality of actuators operatively connected with the first end blade and the second end blade, including:
• i. a first actuator coupled to the first end blade and adapted to effect actuator-driven pivotal motion of the first end blade, and
• ii. a second actuator coupled to the second end blade and adapted to effect actuator-driven pivotal motion of the second end blade, and
• wherein the actuator assembly is adapted to effect independent pivotal motion of the first end blade and pivotal motion of second end blade thereby effecting independent control of ϕ1 and ϕ2.