US2322632A - Covering for airfoil surfaces - Google Patents
Covering for airfoil surfaces Download PDFInfo
- Publication number
- US2322632A US2322632A US318664A US31866440A US2322632A US 2322632 A US2322632 A US 2322632A US 318664 A US318664 A US 318664A US 31866440 A US31866440 A US 31866440A US 2322632 A US2322632 A US 2322632A
- Authority
- US
- United States
- Prior art keywords
- airfoil
- covering
- nap
- filaments
- airfoil surface
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B64—AIRCRAFT; AVIATION; COSMONAUTICS
- B64C—AEROPLANES; HELICOPTERS
- B64C21/00—Influencing air flow over aircraft surfaces by affecting boundary layer flow
- B64C21/10—Influencing air flow over aircraft surfaces by affecting boundary layer flow using other surface properties, e.g. roughness
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T50/00—Aeronautics or air transport
- Y02T50/10—Drag reduction
Definitions
- This invention relates to a covering for an airfoil surface, and aims to reduce skin friction and turbulence.
- My invention is applicable to all the surfaces of an airplane along which the air flows and is of especial value on the wing surfaces. It may also be applied to the surfaces of the propeller blades. It is of especial value in airplanes designed for very high speeds, and is, so far as I am aware, the only type of airfoil surface which will avoid turbulence at speeds above six-tenths of the velocity of sound.
- An airfoil covering embodying my invention consists of a tegument provided with a nap of closely spaced, normally upstanding, fine filaments which are flexible and slightly resilient so that, when the airfoil surface is in motion, the filaments of the nap are bent down by the air flow along the airfoil surface in the direction of the air flow. In this position, they effectively prevent turbulence at high speeds.
- the covering may consist of an ordinary fabric provided with a nap, such as velvet.
- Fig. 1 is a cross-section of an airfoil surface showing the position of the nap when the airfoil is stationary
- Fig. 2 is a similar view showing the position of the nap when the airfoil surface is moving rapidly through th air.
- A represents glass fibres of less than 0.004 inch in diameter and preferably about inch in length.
- B represents a tegument in which the inner ends of the filaments are held.
- the glass filaments A of the nap when in their normal or upstanding position when the airfoil is stationary are inclined rearwardly at an angle of about 45 to the airfoil surface.
- the filaments of the forward part of the surface are bent down more nearly in line with the surface while those at the rear part of the surface remain substantially in their normal position, both the depressed and upstanding fibres being inclined in the direction of the air flow along the surface.
- a covering for an airfoil surface comprising a nap of flexible glass filaments normally inclined outwardly relative to the airfoil surface in the direction of the airflow along said surface.
- a covering for an airfoil surface comprising a nap of glass filaments less than 0.004 inch in diameter normally inclined outwardly relative to the airfoil surface in the direction of the airfiow along said surface.
- a covering for an airfoil surface comprising a tegument and a multiplicity of fibres set in said tegument at an acute angle so that they extend upwardly therefrom in the direction of air flow along the surface, the fibres being sufficiently flexible to be bent down in the direction of air flow by flow of air along the surface.
Landscapes
- Engineering & Computer Science (AREA)
- Aviation & Aerospace Engineering (AREA)
- Laminated Bodies (AREA)
Description
June 22, 1943. w. HARPER, JR
COVERING FOR AIRFOIL SURFACES Filed Feb. 13, 1940 ,Illl lll'.
INVENTOR Wzz/A/y 4/45/29?) (/5? ATTORNEY Patented June 22, 1943 UNITED STATES PATENT OFFICE 3 Claims.
This invention relates to a covering for an airfoil surface, and aims to reduce skin friction and turbulence.
As a result of experiments and investigation I have discovered that the so-called skin friction of an airfoil surface, which is really the effect of turbulence between the boundary layer and the air beyond, may be reduced by providing the airfoil surface with a nap whose filaments may be bent down in the direction of air flow along the surface.
My invention is applicable to all the surfaces of an airplane along which the air flows and is of especial value on the wing surfaces. It may also be applied to the surfaces of the propeller blades. It is of especial value in airplanes designed for very high speeds, and is, so far as I am aware, the only type of airfoil surface which will avoid turbulence at speeds above six-tenths of the velocity of sound.
An airfoil covering embodying my invention consists of a tegument provided with a nap of closely spaced, normally upstanding, fine filaments which are flexible and slightly resilient so that, when the airfoil surface is in motion, the filaments of the nap are bent down by the air flow along the airfoil surface in the direction of the air flow. In this position, they effectively prevent turbulence at high speeds.
The covering may consist of an ordinary fabric provided with a nap, such as velvet.
An important feature of my invention consists in making the filaments of the nap of glass so that they are durable and not affected by moisture. In order to provide the requisite flexibility, I use glass filaments of less than 0.004 inch in diameter. This preferred form is illustrated in the accompanyiny drawing in which Fig. 1 is a cross-section of an airfoil surface showing the position of the nap when the airfoil is stationary, and Fig. 2 is a similar view showing the position of the nap when the airfoil surface is moving rapidly through th air.
In the drawing, A represents glass fibres of less than 0.004 inch in diameter and preferably about inch in length. B represents a tegument in which the inner ends of the filaments are held.
As appears from Fig. 1, the glass filaments A of the nap when in their normal or upstanding position when the airfoil is stationary are inclined rearwardly at an angle of about 45 to the airfoil surface. When the airfoil is moving rapid- 1y through the air, the filaments of the forward part of the surface are bent down more nearly in line with the surface while those at the rear part of the surface remain substantially in their normal position, both the depressed and upstanding fibres being inclined in the direction of the air flow along the surface.
What I claim is:
l. A covering for an airfoil surface, comprising a nap of flexible glass filaments normally inclined outwardly relative to the airfoil surface in the direction of the airflow along said surface.
2. A covering for an airfoil surface, comprising a nap of glass filaments less than 0.004 inch in diameter normally inclined outwardly relative to the airfoil surface in the direction of the airfiow along said surface.
3. A covering for an airfoil surface, comprising a tegument and a multiplicity of fibres set in said tegument at an acute angle so that they extend upwardly therefrom in the direction of air flow along the surface, the fibres being sufficiently flexible to be bent down in the direction of air flow by flow of air along the surface.
WILLIAM HARPER, J R.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US318664A US2322632A (en) | 1940-02-13 | 1940-02-13 | Covering for airfoil surfaces |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US318664A US2322632A (en) | 1940-02-13 | 1940-02-13 | Covering for airfoil surfaces |
Publications (1)
Publication Number | Publication Date |
---|---|
US2322632A true US2322632A (en) | 1943-06-22 |
Family
ID=23239100
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US318664A Expired - Lifetime US2322632A (en) | 1940-02-13 | 1940-02-13 | Covering for airfoil surfaces |
Country Status (1)
Country | Link |
---|---|
US (1) | US2322632A (en) |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2426334A (en) * | 1943-10-15 | 1947-08-26 | Jr Thomas A Banning | Wing for airplanes and the like |
EP0212167A2 (en) * | 1985-08-06 | 1987-03-04 | Messerschmitt-Bölkow-Blohm Gesellschaft mit beschränkter Haftung | Device to reduce friction drag |
US4650138A (en) * | 1985-09-30 | 1987-03-17 | Internorth, Inc. | Cascaded micro-groove aerodynamic drag reducer |
US4759516A (en) * | 1985-09-30 | 1988-07-26 | Ronald D. Grose | Cascaded turbulence generation inhibitor |
US4867503A (en) * | 1983-11-29 | 1989-09-19 | Rockwell-Golde Gmbh | Wind deflector for sliding roofs of automobiles |
WO1993025432A1 (en) * | 1992-06-05 | 1993-12-23 | Juristbyrån Indirekt Ab | Coating on marine constructions |
US5402964A (en) * | 1993-10-25 | 1995-04-04 | Wygnanski; Israel J. | Interference with vortex formation and control of fluid flow to reduce noise and change flow stability |
EP0659641A1 (en) * | 1993-12-15 | 1995-06-28 | Mitsubishi Jukogyo Kabushiki Kaisha | A fluxional force-generated sound reducing device |
US6789769B2 (en) * | 2001-11-24 | 2004-09-14 | Airbus Deutschland Gmbh | Flexible airflow separator to reduce aerodynamic noise generated by a leading edge slat of an aircraft wing |
US20050039661A1 (en) * | 2003-08-22 | 2005-02-24 | Avinoam Kornblit | Method and apparatus for controlling friction between a fluid and a body |
US7059662B1 (en) * | 2003-12-09 | 2006-06-13 | Drews Hilbert F P | Post pressurizing material treatment for bodies moving through fluid |
US7357442B1 (en) | 2004-12-06 | 2008-04-15 | Drews Hilbert F P | Post pressurizing material treatment for bodies moving through fluid |
US20080236473A1 (en) * | 2006-09-11 | 2008-10-02 | Avinoam Kornblit | Method and apparatus for controlling friction between a fluid and a body |
US7644977B2 (en) | 2004-12-06 | 2010-01-12 | Drews Hilbert F P | Post pressurizing material treatment for bodies moving through fluid |
US20220364582A1 (en) * | 2018-01-08 | 2022-11-17 | University Of Notre Dame | Fibers for reducing drag |
US11530016B2 (en) * | 2016-12-27 | 2022-12-20 | Innovalue B.V. | Coating for long term flow control around marine objects |
-
1940
- 1940-02-13 US US318664A patent/US2322632A/en not_active Expired - Lifetime
Cited By (19)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2426334A (en) * | 1943-10-15 | 1947-08-26 | Jr Thomas A Banning | Wing for airplanes and the like |
US4867503A (en) * | 1983-11-29 | 1989-09-19 | Rockwell-Golde Gmbh | Wind deflector for sliding roofs of automobiles |
EP0212167A2 (en) * | 1985-08-06 | 1987-03-04 | Messerschmitt-Bölkow-Blohm Gesellschaft mit beschränkter Haftung | Device to reduce friction drag |
EP0212167A3 (en) * | 1985-08-06 | 1987-11-19 | Messerschmitt-Bolkow-Blohm Gesellschaft Mit Beschrankter Haftung | Device to reduce friction drag |
US4650138A (en) * | 1985-09-30 | 1987-03-17 | Internorth, Inc. | Cascaded micro-groove aerodynamic drag reducer |
US4759516A (en) * | 1985-09-30 | 1988-07-26 | Ronald D. Grose | Cascaded turbulence generation inhibitor |
WO1993025432A1 (en) * | 1992-06-05 | 1993-12-23 | Juristbyrån Indirekt Ab | Coating on marine constructions |
US5402964A (en) * | 1993-10-25 | 1995-04-04 | Wygnanski; Israel J. | Interference with vortex formation and control of fluid flow to reduce noise and change flow stability |
EP0659641A1 (en) * | 1993-12-15 | 1995-06-28 | Mitsubishi Jukogyo Kabushiki Kaisha | A fluxional force-generated sound reducing device |
US6789769B2 (en) * | 2001-11-24 | 2004-09-14 | Airbus Deutschland Gmbh | Flexible airflow separator to reduce aerodynamic noise generated by a leading edge slat of an aircraft wing |
US20050039661A1 (en) * | 2003-08-22 | 2005-02-24 | Avinoam Kornblit | Method and apparatus for controlling friction between a fluid and a body |
US7156032B2 (en) * | 2003-08-22 | 2007-01-02 | Lucent Technologies Inc. | Method and apparatus for controlling friction between a fluid and a body |
US7059662B1 (en) * | 2003-12-09 | 2006-06-13 | Drews Hilbert F P | Post pressurizing material treatment for bodies moving through fluid |
US7357442B1 (en) | 2004-12-06 | 2008-04-15 | Drews Hilbert F P | Post pressurizing material treatment for bodies moving through fluid |
US7644977B2 (en) | 2004-12-06 | 2010-01-12 | Drews Hilbert F P | Post pressurizing material treatment for bodies moving through fluid |
US20080236473A1 (en) * | 2006-09-11 | 2008-10-02 | Avinoam Kornblit | Method and apparatus for controlling friction between a fluid and a body |
US7455021B2 (en) | 2006-09-11 | 2008-11-25 | Lucent Technologies Inc. | Method and apparatus for controlling friction between a fluid and a body |
US11530016B2 (en) * | 2016-12-27 | 2022-12-20 | Innovalue B.V. | Coating for long term flow control around marine objects |
US20220364582A1 (en) * | 2018-01-08 | 2022-11-17 | University Of Notre Dame | Fibers for reducing drag |
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