United Technologies Corporation

Carrier Corporation

Robert W Paterson

Walter M Presz, Jr

Michael J Werle

Robert H Ealba

Bruce L Morin

John B McVey

Roy Pelmas

An apparatus for attaining improved flow uniformity through and at the exit of an air duct by mixing and distributing the air flow. The apparatus has a wall containing a plurality of convoluted corrugations or lobes arranged in conjunction with an airfoil shaped faired body to form an ejector passage between the wall and the faired body. There is a primary flow passage on the side of the wall opposite the ejector passage. The corrugations extend into both the primary flow and ejector flow passages so that a lobe in one passage is a trough in the other passage. Air flow in the primary flow passage acts to cause a flow through the ejector passage and thus a suction in the inlet to the ejector passage. The suction acts upon streamlines around the apparatus to obtain improved downstream air flow performance. One embodiment of the flow distributor increases the spreading half angle at the exit of an air flow duct. Another embodiment improves the velocity distribution profile across the duct downstream of a bluff body in the duct.

Mixer ejector flow distributor

A conduit for carrying fluid in a downstream direction includes a diffusing section. Downstream extending convolutions in the wall of a diffusing section energize the boundary layer and delay boundary layer separation from the wall surface of the diffusing section or permit an increase in the diffusion angle without the occurrence of separation. Such convolutions are particularly useful when rapid diffusion is required in a short distance, such as in the diffusing section of automotive catalytic converter systems. Such a system carries engine exhaust products from a small, cylindrical pipe into a typically larger elliptical cross-section catalyst filled portion. The convolutions help to more uniformly disperse the exhaust gas throughout the catalyst bed using a relatively short diffusion section.

Convoluted diffuser

In a combustion process streams of fuel, oxidant or combinations of fuel and oxidant pass simultaneously through a combustion region over opposite sides of a plate disposed therein having downstream extending convolutions which create pairs of large scale oppositely rotating vortices. These vortices cause the fuel and oxidant to mix rapidly with each other. A recirculation zone is disposed immediately downstream and adjacent the edge of the convoluted plate, and in one embodiment is created by a step-wise discontinuity in the flowpath. The mixing occurs without introducing large momentum losses and, when the mixture is ignited immediately downstream of the convoluted plate, the flame propagates with a larger than normal spreading angle.

Mechanism for accelerating heat release of combusting flows

To reduce noise, an automotive exhaust tailpipe has a convoluted surface at or near its outlet to generate pairs of counterrotating axial vortices within the exhaust gases just before or just as the gases exit the tailpipe. The convoluted surface may be the internal surface of the tailpipe, or a thin-walled convoluted member may be disposed within the tailpipe near its outlet end.

Automotive exhaust noise attenuator

A thin, convoluted wall member disposed upstream of the inlet of a diffuser generates large-scale vortices having axes in the downstream direction. The vortices enhance mixing within the diffuser and can also energize the boundary layer, thereby improving diffuser performance and delaying the onset of stall. Greater diffusion angles without stall are possible. The member itself creates low losses.

Diffuser with convoluted vortex generator

A fluid dynamic pump, such as an ejector, has a common wall which separates a primary high energy fluid flow passage and a secondary low-energy fluid flow passage. The common wall includes a plurality of adjoining lobes extending in the direction of flow to the outlets of the passages at the downstream end of the common wall. A lobe on one side of the wall forms a corresponding trough on the other side. The common wall therefore has a wave-like shape at its downstream end. Primary and secondary fluid flow from the trough outlets on their respective sides of the common wall and are mixed together rapidly in a mixing region downstream of the outlets. A diffuser is located at the downstream end of the mixing region and enhances the pumping ability of the ejector. Secondary fluid is thereby drawn or pumped into the mixing region as a result of this transfer of energy from the primary stream to the secondary stream. Viscous losses are low during the process.

Fluid dynamic pump

An airfoil-shaped body has a relatively thin trailing edge with a series of alternating, adjoining, downstream extending troughs and ridges in its suction surface which form wave-like surface undulations terminating at the trailing edge. The ridges in the suction surface form corresponding troughs in the pressure surface near the trailing edge; and the troughs in the suction surface form corresponding ridges near the trailing edge of the pressure surface. The resulting airfoil-shaped body has a trailing edge with a wave-like shape. The trough and ridge construction delays or prevents two-dimensional boundary layer separation without creating an undesirable drag penalty.

Airfoil-shaped body

In a heat exchanger, a convoluted plate disposed in a fluid stream flowing in an axial direction generates adjacent counterrotating, large scale axial vortices downstream thereof adjacent a wall over which the fluid flows. The convoluted plate is constructed to produce minimum pressure losses, while the vortices increase the heat transfer rate between the fluid and the wall.

Heat transfer enhancing device

An airfoil has a plurality of spaced apart, U-shaped troughs in either or both its suction or pressure surface in the trailing edge region. Each trough extends in a direction generally parallel to the bulk fluid flow in its vicinity near the airfoil surface and has an outlet at the trailing edge. The troughs increase in depth from their inlets toward their outlets, the maximum depth being no more than half the trailing edge thickness. The troughs are spaced apart, sized and configured to flow full over their entire length and to cause fluid to flow into the space immediately behind the trailing edge, thereby reducing base drag.

Airfoil trailing edge

A projectile having a downstream extending surface of revolution which terminates as a blunt base has a plurality of circumferentially spaced apart U-shaped, downstream extending troughs in its surface. Each trough is essentially aligned with the direction of the bulk fluid flow adjacent the surface in the vicinity of the trough, and intersects the blunt base to form a trough outlet therein. The troughs are appropriately spaced apart, sized and configured to flow full over their entire length and to cause fluid to flow into the space immediately behind the blunt base, thereby reducing base drag on the projectile.

Projectile with reduced base drag

A body adapted to move downstream through a fluid has a downstream extending smooth surface terminating at a blunt base. A plurality of adjacent U-shaped, downstream extending troughs in the smooth surface intersect the blunt base to form trough outlets. The troughs are appropriately spaced apart, sized and configured to flow full over their entire length and cause fluid to flow into the space immediately behind the blunt base, thereby reducing base drag on the body.

Bodies with reduced base drag

A casing surrounding a fluid stream over which an unbounded fluid flows in a downstream direction has a plurality of alternating, adjoining troughs and ridges in its external surface, extending in the downstream direction to a thin trailing edge of the casing, which will thereby have a wave-like shape.

Bodies with reduced surface drag

A body adapted to move downstream through a fluid has a downstream extending smooth surface terminating at a blunt base. Extending transversely across the smooth surface and disposed upstream of the blunt base is a thin, downstream extending plate closely spaced from the smooth surface. At least the downstream end portion of the plate is convoluted such that its downstream end is wave shaped. The convolutions are designed to generate pairs of counterrotating vortices which delay boundary layer separation from the smooth surface and cause fluid to flow into the space immediately behind the blunt base, reducing base drag on the body. The device generates very little drag of its own.

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Simsbury, CT, United States of America

Robert W Paterson