US3082827A - Marine propeller - Google Patents

Marine propeller Download PDF

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Publication number
US3082827A
US3082827A US189134A US18913462A US3082827A US 3082827 A US3082827 A US 3082827A US 189134 A US189134 A US 189134A US 18913462 A US18913462 A US 18913462A US 3082827 A US3082827 A US 3082827A
Authority
US
United States
Prior art keywords
blade
pitch
propeller
hub
trailing edge
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
Application number
US189134A
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English (en)
Inventor
Rosen George
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Raytheon Technologies Corp
Original Assignee
United Aircraft Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority to NL289030D priority Critical patent/NL289030A/xx
Priority to NL125791D priority patent/NL125791C/xx
Priority to BE629694D priority patent/BE629694A/xx
Priority to US189134A priority patent/US3082827A/en
Application filed by United Aircraft Corp filed Critical United Aircraft Corp
Priority to DE19631581130D priority patent/DE1581130B1/de
Priority to DK49363AA priority patent/DK111014B/da
Priority to CH131163A priority patent/CH415333A/de
Priority to GB7569/63A priority patent/GB965999A/en
Priority to FR927923A priority patent/FR1351125A/fr
Application granted granted Critical
Publication of US3082827A publication Critical patent/US3082827A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B64—AIRCRAFT; AVIATION; COSMONAUTICS
    • B64C—AEROPLANES; HELICOPTERS
    • B64C11/00—Propellers, e.g. of ducted type; Features common to propellers and rotors for rotorcraft
    • B64C11/16—Blades
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H1/00—Propulsive elements directly acting on water
    • B63H1/02—Propulsive elements directly acting on water of rotary type
    • B63H1/12—Propulsive elements directly acting on water of rotary type with rotation axis substantially in propulsive direction
    • B63H1/14—Propellers
    • B63H1/26—Blades
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
    • B63H—MARINE PROPULSION OR STEERING
    • B63H3/00—Propeller-blade pitch changing

Definitions

  • An object of this invention is a propeller construction providing the optimum hydrodynamic shape for supercavitating propellers over the complete operating speed range of the propelled vehicle.
  • a further object is a propeller construction matching a controllable pitch and a fixed pitch pair of blade elements to provide the optimum hydrodynamic shape for a supercavit-ating marine propeller blade.
  • a further object is a marine supercavitating propeller construction having a main blade portion pivotally mounted in a hub for pitch changing movement and a fixed auxiliary blade portion supported by said hub nesting with, and extending forward from the trailing edge of said main portion for less than half the chord of the main portion.
  • FIG. 1 is a side elevation of a propeller incorporating the invention
  • FIG. 2 is a view partly in section showing the relation of the main and auxiliary blades in "high pitch position
  • FIG. 3 is a view similar to FIG. 2 showing the blade in low pitch position
  • FIG. 4 is a section similar to FIG. 2 showing the blade in reverse pitch position
  • FIG. 5 is a side elevation similar to FIG. 1 showing a modified form of the adjustable blade
  • FIG. 6 is a view similar to FIG. 2 showing a section through the modified portion of the blade.
  • Controllable pitch does not, however, solve the propeller cavitation problem with its associated adverse effects on performance, noise and blade erosion.
  • the propeller With its added rot-ative speed, experiences cavitation sooner than any other component of the vehicle, and it has become evident that suppression of propeller cavitation becomes impossible at speeds above 4050 knots, even if the propulsion unit is lightly loaded. Consequently, there has been active interest in the application of supercavitating foils to marine propellers as a means of alleviating cavitational losses.
  • supercavitating marine propeller presents several difficult and conflicting design problems. These stem principally from the radical shape of the supercavitating foil.
  • the present invention is aimed at a practical solution to these design problems in a controllable pitch supercavitating marine propeller.
  • This objective is achieved by splitting the supercavitating blade into two elements as shown in the drawings.
  • Element 10 becomes the controllable pitch portion of the blade and element 12 is maintained as a fixed pitch portion.
  • FIG. 2 shows the two elements aligned for the design maximum speed condition where in conjunction with each other they form an optimum supercavitating blade section shape.
  • the element -10 nests with and overlaps the element 12 which is arranged to nest with the trailing portion of the element 10.
  • the trailing edge 14- of the composite blade is formed primarily of the blunt edge of the element 12 and to a minor extent by the relatively sharp trailing edge of the element 10.
  • the trailing edges of the two elements are substantially coextensive throughout the planfor-m of the element 10.
  • the element spaced from but comparatively adjacent to the pitch changing axis 18 of the movable element.
  • Element 12 is fixed on or secured to a hub 20 by any suitable means and may even be integral with the hub, if desired.
  • the movable portion 10 is rotatably mounted in the hub 20 for pitch changing movement about a pitch changing axis 18 in any suitable and Well known manner.
  • it is shown as supported in a journal 22 in the propeller hub and held therein by a flange 24.
  • this schematic showing is for purposes of illustration only and that any suitable well-known mounting may be used.
  • Any suitable and well-known mechanism may be used for changing the propeller pitch.
  • this mechanism is shown as a plunger 26 longitudinally movable along the axis 28 of rotation of the propeller hub 20.
  • a pin 38 depending from one side of the flange 24 is received in a transverse slot 32 in the plunger 26 and serves to transform longitudinal movements of the plunger 26 into pitch changing movements of the element 10.
  • the hub 20 is supported upon a shaft 34 which in turn is mounted in bearings, not shown, for rotatably supporting the propeller about the axis 28.
  • the propeller may be driven by an engine 36 drivingly connected with the propeller shaft 34 by gears 38 and 40.
  • the propeller pitch may be controlled by any suitable and well-known means such as a manual control or it may be controlled by a speed responsive governor 42 operatively connected with the plunger 26 by a rod 44.
  • the governor may be of any well-known construction and obtain its speed signal directly from the shaft 34 or from the engine 36.
  • FIG. 2 shows the elements 10, 12 nested in overlapping relation to form in effect the single supercavitating blade in the design maximum speed condition and having a cross-section of a typical supercavitating blade with its relatively sharp leading edge and the blunt trailing edge.
  • the design maximum speed position is the highest pitch position attainable in the propeller and represents the optimum angle of attack for the blade sections at the selected high vehicle speed and the corresponding rotating speed of the propeller which is selected to provide the most favorable advance ratio and cavitation index at this design condition.
  • the upper or camber side 53 of the element 12 is given a shape extending from the relatively sharp leading edge of the element 12 which will be generally convex and which, in conjunction with the complementary face side 52 of the element 10 (generally concave in shape), forms a curved divergent slot for maximum turning of the flow in order to achieve maximum lift.
  • the curvature of the two complementary surfaces 52 and 53 need not be identical, but will be selected to provide the most favorable flow conditions for the low pitch positions of the specific application, and with the sole limitation that this will not interfere with the attainment of the desired contour of the face side of the blade when in the design maximum speed position.
  • the element 12 being arranged at a favorable angle of attack because of the flow directing effect of the face surface 54 of the element 10, acts as a high lift device to increase the thrust and the performance of the propeller at the lower forward speeds of the vehicle.
  • the divergent slot acts in a manner similar to that in a slotted flap construction and assists in maintaining flow with a favorable pressure gradient over the camber face of the element 12 and assists in preventing separation of flow on its camber surface.
  • the governor will increase the propeller pitch on element 10 in order to maintain the desired engine speed, until the design vehicle maximum speed is obtained. The vehicle will thus be brought from its rest or slow speed condition to the design cruise condition without encountering adverse angles of attack on the blade sections with accompanying flow disturbance and loss in performance.
  • each blade comprising a main blade portion, having a sharp leading and a sharp trailing edge, pivotally mounted in said hub for pitch changing movements, a minor blade portion fixed on said hub and having a sharp leading edge and a blunt trailing edge and nesting with said main blade portion in the high pitch position to provide a composite blade having a sharp leading edge and a blunt trailing edge and providing separated blade portions with a slot between the portions in lower pitch positions.
  • a radially extending blade having a sharp leading edge and a blunt trailing edge, said blade formed of a radially pivoted section and a fixed section, said fixed section having a sharp leading edge and a blunt trailing edge forming substantially the entire trailing edge of said blade and extending less than half the chord Width of said blade from said blade trailing edge toward the pivotal axis of said radially pivoted section.
  • a supercavitating propeller having a blade with a design condition producing substantially stable cavitation over the chordwise length of the blade, means maintaining favorable lift/ drag relations at off-design conditions comprising means reducing the pitch of a portion of the blade including substantially the entire camber surface, and means maintaining a portion of the blade including the rear portion of the face of the blade in fixed position, to receive fluid directed by the remainder of the face of said blade, and form a diverging slot between the two blade portions.
  • a blade as claimed in claim 3 in which the two blade portions overlap and nest to form a single blade section in the high pitch position of the blade.
  • a hub In a supercavitating propeller, a hub, a plurality of blades radiating from said hub, each blade comprising a rear section formed integral with said hub, and a movable section extending forward of and overlapping said integral section and pivotally supported by said hub on an axis forward of said integral section.
  • a hub blades radiating from said hub, each blade designed to have a stable cavitating layer at design conditions on its camber surface, means to reduce the blade pitch to prevent serious flow disturbance at speeds less than the design speed and a high lift device associated with said blade comprising a fixed blade section fixed with respect to said hub and nesting with said blade at design conditions, and forming a diverging slot with the trailing portion of the face side of said blade at said reduced pitch.
  • a hub comprising a controlla-ble pitch portion and a fixed portion having a chord less than half the chord of the controllable portion and having a trailing edge substantially coextensive in planform with the trailing edge of the controllable portion and nesting with said controllable portion in the high pitch position to form essentially a unitary blade and separated from said controllable portion by a diverging slot at lower pitch positions, said fixed portion having a relatively sharp leading edge and a relatively thick trailing edge.
  • a hub comprising a main blade portion pivotally mounted in said hub adjacent the blade center line for pitch changing movements and a fixed auxiliary blade portion supported by said hub, nesting with the face side of, and extending forward from the trailing edge of, said main portion for less than half the chord of the main portion, to a position downstream of the pivotal of said main portion.
  • an auxiliary blade portion having a chord 30% to 40% of the chord of the main blade portion.
  • a marine propeller as claimed in claim 7 including means responsive to the speed of the propeller for controlling the pitch of the propeller.
  • a hub comprising an adjustable portion extending the full chord of the blade and a fixed portion supported by the hub and extending less than half of the chord of the blade from the trailing edge of the blade, on the face side, means for moving said adjustable portion in a pitch reducing direction relative to the hub and the fixed portion to reduce the pitch of the movable portion, and open up a divergent slot between said portions, said fixed portion having a sharp leading edge and a shape to present a blade section to flow directed by the face of said movable portion in its reduced pitch position to provide a high lift device.
  • a supercavitating propeller blade having a mov able portion extending the entire chord Width of the blade at the outer section but tapering inward to less than the entire chord Width of the blade at the inner section, a fixed portion having a camber side nesting with the face side of the trailing section of the movable portion and having a sharp leading edge and a blunt trailing edge extending the entire length of the blade trailing edge, said camber side forming a supercavitating blade section extension of said movable section in the inner section of the blade.
  • High lift mechanism for a supercavitating propeller comprising a blade having a movable portion forming substantially the entire camber face of the blade, a fixed portion nesting with the face of said movable portion and forming a portion of the trailing section of the face of the blade when the two portions are nested, and forming a high lift device for said blade when the movable portion is moved away from nesting position.
  • Means for improving the performance of an adjustable pitch, supercavitating propeller comprising a blade having a movable portion pivoted on a pitch changing axis for pitch changing movement and forming substantially the entire camber face of the blade, and a fixed portion nesting with the trailing section of the face side of said movable portion and forming a minor portion of the face of said blade, said movable portion trailing sectionmovable on its pitch changing axis, in a pitch reducing direction, away from said fixed portion, to provide a high lift structure with the fixed section having a shape forming a diverging slot and a high lift member with said movable section.
  • a hub an adjustable pitch supercavitating propeller blade pivotally supported by said hub and having a split trailing section, said split section comprising a flap section forming a portion of the face of said blade and fixed With respect to said hub and having a sharp leading edge and a blunt trailing edge and having a chord width less than half the blade chord width, the remainder of said blade pivoted to move toward and away from said flap section in pitch changing movements to open and close a diverging slot opening on the face side of said blade and discharging between the trailing edge of said blade and said flap section.
  • a propeller as claimed in claim 9 in which the maximum blade thickness of both the blade and the auxiliary blade portion is at their respective trailing edges.

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  • Engineering & Computer Science (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • Ocean & Marine Engineering (AREA)
  • Structures Of Non-Positive Displacement Pumps (AREA)
US189134A 1962-04-20 1962-04-20 Marine propeller Expired - Lifetime US3082827A (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
NL289030D NL289030A (xx) 1962-04-20
NL125791D NL125791C (xx) 1962-04-20
BE629694D BE629694A (xx) 1962-04-20
US189134A US3082827A (en) 1962-04-20 1962-04-20 Marine propeller
DE19631581130D DE1581130B1 (de) 1962-04-20 1963-01-31 Schiffspropeller mit vollkavitierendem Fluegelprofil
DK49363AA DK111014B (da) 1962-04-20 1963-02-01 Skibsskrue.
CH131163A CH415333A (de) 1962-04-20 1963-02-01 Schiffspropeller
GB7569/63A GB965999A (en) 1962-04-20 1963-02-26 Marine propeller
FR927923A FR1351125A (fr) 1962-04-20 1963-03-14 Hélice marine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US189134A US3082827A (en) 1962-04-20 1962-04-20 Marine propeller

Publications (1)

Publication Number Publication Date
US3082827A true US3082827A (en) 1963-03-26

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Application Number Title Priority Date Filing Date
US189134A Expired - Lifetime US3082827A (en) 1962-04-20 1962-04-20 Marine propeller

Country Status (7)

Country Link
US (1) US3082827A (xx)
BE (1) BE629694A (xx)
CH (1) CH415333A (xx)
DE (1) DE1581130B1 (xx)
DK (1) DK111014B (xx)
GB (1) GB965999A (xx)
NL (2) NL289030A (xx)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3333562A (en) * 1963-12-24 1967-08-01 Newport News S & D Co Ship structure and handling means for underwater mining
US3418960A (en) * 1965-05-14 1968-12-31 Defence Uk Vehicle wheels
US3693575A (en) * 1969-12-27 1972-09-26 Rudolf Mades Ship{3 s drive and method of operating the same
JPS50111795A (xx) * 1973-03-20 1975-09-02
US4371350A (en) * 1980-01-28 1983-02-01 Escher Wyss Gmbh Marine vessel with propeller
US5733156A (en) * 1994-12-21 1998-03-31 Honda Giken Kogyo Kabushiki Kaisha Variable propeller for boat
CN104340348A (zh) * 2013-07-31 2015-02-11 应用热流分析中心股份有限公司 复合式螺桨扇叶构造

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2550889A (en) * 2016-05-27 2017-12-06 Teignbridge Propellers International Ltd Adjustable pitch propeller

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1344496A (en) * 1917-10-06 1920-06-22 Albert L Flattum Aerial propeller
US2145805A (en) * 1936-08-13 1939-01-31 Allis Chalmers Mfg Co Propeller type hydraulic machine
US2982361A (en) * 1958-12-19 1961-05-02 United Aircraft Corp Variable camber blading

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1344496A (en) * 1917-10-06 1920-06-22 Albert L Flattum Aerial propeller
US2145805A (en) * 1936-08-13 1939-01-31 Allis Chalmers Mfg Co Propeller type hydraulic machine
US2982361A (en) * 1958-12-19 1961-05-02 United Aircraft Corp Variable camber blading

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3333562A (en) * 1963-12-24 1967-08-01 Newport News S & D Co Ship structure and handling means for underwater mining
US3418960A (en) * 1965-05-14 1968-12-31 Defence Uk Vehicle wheels
US3693575A (en) * 1969-12-27 1972-09-26 Rudolf Mades Ship{3 s drive and method of operating the same
JPS50111795A (xx) * 1973-03-20 1975-09-02
JPS5850920B2 (ja) * 1973-03-20 1983-11-12 エ− ビ− ヴオルヴオ ペンタ 舟艇プロペラ
US4371350A (en) * 1980-01-28 1983-02-01 Escher Wyss Gmbh Marine vessel with propeller
US5733156A (en) * 1994-12-21 1998-03-31 Honda Giken Kogyo Kabushiki Kaisha Variable propeller for boat
CN104340348A (zh) * 2013-07-31 2015-02-11 应用热流分析中心股份有限公司 复合式螺桨扇叶构造

Also Published As

Publication number Publication date
DK111014B (da) 1968-04-29
NL125791C (xx)
BE629694A (xx)
DE1581130B1 (de) 1970-09-24
CH415333A (de) 1966-06-15
GB965999A (en) 1964-08-06
NL289030A (xx)

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