US3741285A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Boundary layer control of flow separation and heat exchange
Assignee: KUETHE ARNOLD M
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Filing: 1970-10-12
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Granted: 1973-06-26
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Expires: 1990-10-12
Abstract
Abstract Boundary layer control for delay or prevention of flow separation and/or increase in rate of heat exchange between a surface and a fluid by an arrangement of surface elements which may take the form of either crests or discreet concave depressions in the surface, having effective depths or dimensions of less that that of the adjacent boundary layer thickness, to cause the formation of vortices with succeeded surface elements being positioned to cause vortex amplification, for effective boundary layer mixing with less drag, weight penalty, noise, and energy loss than that of conventional vane-type generators.
Inventors
- 👤 A Kuethe
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 16:50
CPC Classifications
F; F28; F28F; F28F13/00; F28F13/06; F28F13/12; B; B64; B64C; B64C21/00; B64C21/10; B64C23/00; B64C23/06; F01; F01D; F01D5/00; F01D5/12; F01D5/14; F01D5/141; F01D5/145; F28F1/00; F28F1/10; F28F1/12; F28F1/24; F28F1/32; F05; F05D; F05D2250/00; F05D2250/20; F05D2250/21; F05D2250/22; F05D2250/24; F05D2250/70; F05D2250/71; F05D2250/711; F05D2250/712; Y; Y02; Y02T; Y02T50/00; Y02T50/10; Y02T50/60
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
124 words
Apparatus for increasing the rate of heat exchange between two fluid mediums of different temperatures, comprising a plurality of transversely spaced apart fins defining longitudinal passages therebetween for the flow of one of said mediums, a plurality of tubes extending transversely through said fins and defining passageways therein for the flow of the other of said fluid mediums, means on said fins defining a plurality of elongated flow diverting elements having a transverse height less than the thickness of the adjacent boundary layer of said one fluid medium and inclined at an acute angle to the direction of flow of said one medium for forming in said boundary layer a plurality of streamwise vortices to increase the rate of heat exchange between said mediums.
Claim 2
Dependent Claim
124 words
Apparatus for increasing the rate of heat exchange between two fluid mediums of different temperatures, comprising a plurality of transversely spaced apart fins defining longitudinal passages therebetween for the flow of one of said mediums, a plurality of tubes extending transversely through said fins and defining passageways therein for the flow of the other of said fluid mediums, means on said fins defining a plurality of elongated flow diverting elements having a transverse height less than the thickness of the adjacent boundary layer of said one fluid medium and inclined at an acute angle to the direction of flow of said one medium for forming in said boundary layer a plurality of streamwise vortices to increase the rate of heat exchange between said mediums.
Claim 3
Dependent Claim
131 words
Apparatus for increasing the rate of heat exchange between two fluid mediums of different temperatures separated by impervious barrier means defining surfaces contiguous with each of said mediums, comprising means on one of said surfaces defining a plurality of elongated flow diverting elements which have amplitudes which are less than the thickness of the boundary layer in the adjacent one of said fluid mediums and which have lengths which are substantially greater than the boundary layer thickness extending in a direction generally transversely to, but inclined at an angle from 20* to 40* to, the direction of flow of said one fluid medium for forming in said boundary layer a corresponding plurality of streamwise vortices extending downstream adjacent said one surface to increase the rate of heat exchange between said mediums.
Claim 4
Dependent Claim
131 words
Apparatus for increasing the rate of heat exchange between two fluid mediums of different temperatures separated by impervious barrier means defining surfaces contiguous with each of said mediums, comprising means on one of said surfaces defining a plurality of elongated flow diverting elements which have amplitudes which are less than the thickness of the boundary layer in the adjacent one of said fluid mediums and which have lengths which are substantially greater than the boundary layer thickness extending in a direction generally transversely to, but inclined at an angle from 20* to 40* to, the direction of flow of said one fluid medium for forming in said boundary layer a corresponding plurality of streamwise vortices extending downstream adjacent said one surface to increase the rate of heat exchange between said mediums.
Claim 5
Dependent Claim
161 words
In a heat exchanger having means defining a series of spaced apart tubes through which a fluid flows to be cooled or heated and in which a plurality of fins are attached to the tubes to define air passages extending transversely of said tubes through which air flows, the improvement comprising means on said fins defining vortex inducing generators in the form of elongated flow diverting elements, said elements having a height extending partially into the boundary layer air adjacent the surface of said fins and extending in a direction transversely to, but inclined at acute angle to the direction of air flow for causing the formation of streamwise vortices in the air stream extending along the streamline of the flow between said tubes to improve the rate of heat exchange between the air moving through said passages and the fluid moving through said tubes and delaying or preventing a region of separated flow between the air stream through said passages.
Claim 6
Dependent Claim
161 words
In a heat exchanger having means defining a series of spaced apart tubes through which a fluid flows to be cooled or heated and in which a plurality of fins are attached to the tubes to define air passages extending transversely of said tubes through which air flows, the improvement comprising means on said fins defining vortex inducing generators in the form of elongated flow diverting elements, said elements having a height extending partially into the boundary layer air adjacent the surface of said fins and extending in a direction transversely to, but inclined at acute angle to the direction of air flow for causing the formation of streamwise vortices in the air stream extending along the streamline of the flow between said tubes to improve the rate of heat exchange between the air moving through said passages and the fluid moving through said tubes and delaying or preventing a region of separated flow between the air stream through said passages.
Claim 7
Dependent Claim
23 words
The apparatus of claim 1 in which said wave elements form a plurality of V-shaped crests having a semi-apex angle of from 20*-40*.
Claim 8
Dependent Claim
16 words
The apparatus of claim 1 in which said tubes have a fineness ratio greater than unity.
Claim 9
Dependent Claim
23 words
The apparatus of claim 1 in which said fins are formed of sheet metal and said elements are stamped into the sheet metal.
Claim 10
Dependent Claim
27 words
The apparatus of claim 2 in which said elements are arranged in a plurality of transversely-spaced V-shaped arrays having downstream surfaces defining troughs of a corresponding configuration.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-25 | 1976-12-25 | 1977-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-25 | 1980-12-25 | 1981-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-25 | 1984-12-25 | 1985-06-26 | $7700.00 | Window Closed / Lapsed |