US2978206A - Radial flow lift device - Google Patents

Description

Aprll 4, 1961 D. s. JOHNSON RADIAL FLow LIFT DEVICE ed Lf 11.11. v .a

April 4, 1961 D. s. JOHNSON 2,978,206

RADIAL FLOW LIFT DEVICE Filed Feb. 27, 1959 3 Sheets-Sheet 2 INVENTOR.

MMM ,5f Johns/azz TTFNEYS D. S. JOHNSON RADIAL FLOW LIFT DEVICE 4.April 4, 1961 3 Sheets-Sheet 3 Filed Feb. 27, 1959 RADIAL FLW LEFT 'DEVECE Donald S. Johnson, Dunn Loring, Va. (Box 644, Falls Church, Va.)

Filed Feb. 27, 1959, Ser. No. 795,944

Claims. (Cl. 244-23) is limited by certain operational features, i.e., the relative movement of the rotating air screw or propeller must not exceed Mach 1. As some of these lpropellers are rather long and rotate at fairly high velocities, the tips thereof have rather high relative velocities. When the helicopter is travelling horizontally, one-half Vof each rotation of the propeller has a component in the same direction as the helicopter Vis moving, and the other half of the rotation has a component in the reverse direction. In computing the relative air speed of the propeller, this component in the same direction of translation of the helicopter is added to rotational velocity of the propeller, so it becomes evident that it is necessaryV to maintain the rotational and/orthe translatory velocities within definite controlled limits to avoid any portion of the rotating propeller from exceeding Mach l. As the weight of the pay load and the rate of translatory speed is a function of the r.p.m. of the rotating propeller, it becomes fur; ther evident that the above limitation or relative speeds not exceeding Mach l places acorresponding limitation on the pay load and/ or the translatory speed.

It is an object of this invention, therefore, vto provide a novel form of lift device which has no propeller and, therefore, is not limited by the disadvantages thereofdescribed in the Vpreceding paragraph.

It is a further object of the invention to provide :a novel form of lift device which obtains its lift fromtne passage of a high velocity iiuid current over a generally parabolic surface of revolution.

It is a further object of the invention 'to provide a novel form of lift device which obtains its lift by virtue of the passage of a high velocity fluid current over a generally parabolic surface of revolution, including spaced thrust spoilers to produce an unbalanced lift on selected areas to provide a force having a horizontal component to obtain horizontal movement of the lift device.

lt is a further object of the invention toprovide a novel form of lift device, vwhich obtains its lift by virtue ofthe passage of a high velocity fluid current over a generally parabolic surface of revolution including adjustable vanes to counterbalance torque.

It is a further object of the invention to provide va novel form of lift device which obtains its lift by virtue of the passage of a high velocity air current over a generally parabolic surface of f revolution, and means to 'provide the air current including an engine driven impeller. v

It is a still further object of the invention to provide,

'in a novel #form o f liftdeviee which obtains its lift by virtue ofthe passage of a high velocity air current over `a Patented Apr.. 4, lgl

generally parabolic surface of revolution, an engine driven impeller to provide the air current and a plurality of thrust spoilers adjacent to the surface, and a single control member for the engine and for the thrust spoilers.

These and other objects will be apparent from the following description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a top plan view of the lift device;

Fig. 2 is a side elevational View with certain parts broken away for clarity;

Fig. 3 is an enlarged fragmentary vertical sectional view substantially on the line 3 3 of Fig. l;

Fig. 4 is an enlarged fragmentary horizontal sectional View of the control mechanism on the line 4--4 of Fig. 3;

Fig. 5 is a fragmentary sectional View of the control mechanism on the line 5 5 of Fig. 4;

Fig. 6 is an enlarged fragmentary vertical sectional View of the control mechanism on the line 6--5 of Fig. 5; n

Fig. 7 is an enlarged fragmentary horizontal'sectional view substantially on the line 7--7 of Fig. 2 showing the torque counterbalancing mechanism;

Fig. 8 is a fragmentary vertical sectional View on the line -8-8 of Fig. 7; and v Fig. 9 is a graph showing a method of developing the curvature for the airfoil surface.

ln the description which follows, the same element in the several figures is designated bythe same reference numeral. K

Referring more particularly to the structure shown in Fig. 3, the lift device includes a framing structure cornprising a smaller upper circular tubular member it), and a pair of concentric lower tubular members, comprising an inner tubular member l2 and an outer tubular member 14. The tubular members 12 and 14 lie in the same plane and are connected together by means of a plurality of diagonal horizontal struts lr6, as more clearly shown in Fig. l. The members lil, l2 and i4 are preferably tubular in form, in order to save weight, and are made of any suitable material, such as steel, aluminum,

n later in the specification.

.aluminum-magnesium alloys, etc.

interposed between the tubular members 10 and la, are a plurality of spaced stringers 18, the upper surfaces of which are curved for a purpose to be set forth hereinafter. -The upper and lower tubular members l0 and l2 are held in spaced relation by means of a plurality of spaced vertical struts Zit, The various members comprising the framework are interconnected by any well known means, such as, for instance, by welding, to form a rigid structure.

The tubular members lil and i4 are circular or ringshaped in form. The tubular member 12 is circular for the major part of its circumference, and, as shown in Fig. 4, includes a straight or chord portion 2d serving as a support for controlling members, to be described Supported from the tubular structure l2, by means of a plurality of upwardly inclined struts or supports Z, is a horizontally disposed engine supporting frame 26 to which is mounted an engine Sil.

The frame structure above described is covered with a skin 32 comprising the airfoil of the device. The airfoil generally approximates a parabolic surface of revolution having the focal point close to the peak of the parabola. rl`he upper surfaces of the stringers l are designed to follow the contour of the parabola, so that the skin 32, when extended over the stringere i8, assumes and retains the desired form. The skin 32. may be made of any desirable material commonly used in the construction of aircraft airfoils. in the example Shown,

10W weight. The skin may be secured to the frame 3 structure in any desired manner to obtain a rigid structure. Openings 34 are made in the stringers 18 to reduce weight. p Y

From the foregoing, it is seen from Figs. 2 and 3, that an umbrella-like structure `is provided. An opening 36 is provided in the skin, which opening is slightly smaller in diameter than the diameter of the tubular member 10. Mounted to rotate within the'said opening 36 is an engine driven impeller 38, connected to the engine shaft 40 to rotate therewith. The impeller includes a disk 42 having a diameter equal to the opening 36, and a curved surface conforming generally to the parabolic shape of the skin 32. Attached to the center portion of said disk 42, by means of a plurality in rivets 46, is an entrance cone 44. Extended from the outer end of the cone 44, and curving generally radially outwardly, are a plurality of impeller blades 48, clearly shown in Figs. 1 and 3. The impeller blades 48 extend at an angle to the radius, and, referring to Fig. l, rotate in a counterclockwise direction, as indicated by the arrow. A shroud 50 is attached to and cover the outer sides of the impeller blades to rotate therewith and provides, in conjunction with said impeller blades and with the disk 42, a plurality of passages through which air is directed in a generally radial direction and accelerated by the rotation of the impeller. Between the entrance cone 44 and the shroud 50 is the impeller inlet 52, and a discharge outlet 54 is provided at the outer ends of the vanes. With reference to Figs. 2 and 3, it will be noted that the extrados of the impeller disk 42 and the extrados of the skin 32 are designed to form an almost continuous surface, and that the impeller discharge 54 is related vto the skin 32 so as to direct the discharge from the impeller tangentially over the airfoil surface of the skin 32. The impeller is of the mixed flow type, in which the air enters in an axial direction and -is discharged in a radial direction.

Referring to Figs. l and 3, it will be noted that there is provided, adjacent'the lower or outer end of the airfoil surface, a plurality of spaced deilectors or thrust spoilers 56. Four of these thrust spoilers are shown, spaced 90 apart. The purpose of these thrust spoilers is to obtain horizontal traverse of the apparatus in any desired direction. Each of the spoilers comprises an elongated curved or arcuate surface 58, having a contour corresponding to the extrados of the skin adjacent thereto. The arcuate surface 58 is provided with a pair of end flanges 60, which are pivotally connected at points midway between the upper and lower edges of the curved surface to a pair of spaced upstanding supports 62, carried by the skin 32 and frame structure 14. The. supports 62 and end flanges 60 are pivotally connected, as shown at 64, to permit pivotal movement of the thrust spoiler as will be described in detail hereafter.

In order to counterbalance engine torque, which tends to produce a spin about the vertical axis of the impeller, there is provided a torque counterbalancing device designated in its entirety by the reference number 66. This torque counterbalancing means, more clearly shown in Figs. 2, 7 and 8, comprises a U-shaped frame member 68 mounted in a generally horizontal plane and welded on the inside of the tubular member 14. The bight of the U-shaped frame member 68 is provided with a plurality of spaced openings to receive shafts 70, which extend outwardly toward the tubular member 14. Pivotally attached to and suspended from each opfthe horizontally extending shafts 70 is a deilector vane 72, having attached to the upper part thereof a sleeve 74, which surrounds, in pivotal relation, a shaft 70. A spacing sleeve 76, between the pivotal sleeve 74 and the tubular member 14, prevents axial movement of the vane. With reference to Figs. 2 and 7, it will be noted that the vanes are pivotally mounted for movement below the umbrellalike structure formed by the airfoil and frame, and

that portions of the vanes 72 extend radially beyond the outer end of the airfoil, lying directly in the path of the air discharged from the channel formed by the arcuate surface 58 and the airfoil surface. The inner ends of the vanes are pivotally linterconnected by means of a connecting member 78, to obtain simultaneous movement of the vanes. From the foregoing, it is evident that the vanes are connected for simultaneous swinging movement in a vertical plane.

Below the umbrella-like structure forming the frame and airfoil, there is provided a pilots platform S0, which is connected to the lower inner tubular member 12 by means of a plurality of inclined struts 82, shown in Fig. 2. Extending from the pilots platform is a supporting tripod structure 86, provided with a landing pad J4 under each foot. The tripod structure provides a supporting means for the lift device when on the ground. An instrument panel 88 is attached to one or more of the struts 82 in close proximity to the pilots vision.

Closely adjacent the pilots platform, there is provided a depending control rod 90 mounted for swinging and rotational motion. The purpose of this control rod is to provide a unitary control for the engine and for the thrust spoilers, in order to maneuver the lift device. The engine is provided with a Carburettor 92 having the usual throttle valve, not shown.

The control rod 90 operates the engine throttle valve and the thrust spoilers 56 through a gimbal structure comprising a tubular shaft 96 (Figs. 4, 5 and 6) mounted for pivotal movement in a pair of pivotal supports 94 carried by the chord portion 24 of lower inner tubular frame member 12. The tubular shaft 96 includes a section 98 having an elongated slot 100 through which the control rod 90 extends. A sleeve 102 surrounds the control rod 90, the rod being free for rotation within said sleeve. Sleeve 102 is provided with an ear 104, through which extends a shaft 106 engaging opposite side walls of the slot to pivotally support the sleeve 102 for movement in a vertical plane. A lever 110, surrounding the control rod 90 and attached thereto by means of a set screw 112, rests on the upper end of sleeve 102. One end of tubular shaft 96 is provided with an upstanding arm 108 for connection with a pair of opposite thrust spoilers Iby means described hereinafter.

The upper end of control rod 90 receives a cap 114 which is attached thereto by means of a stud bolt 116 and nut 118. Welded to cap 114, on opposite sides, are a pair of plates 120, to which control links 122 are connected by means of pivotal connections 124. Other links 126 are pivotally connected at 128 to the outer end of upstanding arm 108.

From the foregoing description, it is apparent that the lgimbal structure provides a universal mounting for the control rod 90. Referring to Fig. 5, movement of the lower end of the control rod from left to right would produce a pivotal motion around the shaft 106 and a movement of the upper end of the control rod from right to left. Refering to Figs. 3 and 4, movement of the lower end of control rod 90 from left to right would produce a pivotal movement about the supports 94 and a movement of the upper end from right to left. The links 122 are connected to the upper and lower thrust spoilers 56 shown in Fig. 1, while the links 126 are connected to the right and left thrust spoilers. By virtue of these connections, opposed thrust spoilers are simultaneously and equally moved, but in opposite directions.

A link 130 connects lever 110 to lever 132 on the shaft of the throttle valve of carburetter 92, whereby rotation of the control rod 90 is effective to rotate the engine throttle valve to regulate the speed of the engine.

Referring to Fig. 2, the pilots platform 80 supports a pair of pivotally mounted pedals 134, which are connected by means of the cables 136 and 140, passing overV pulleys 138 and 142, to the lower part of the two outer Vdeiiector vanes 72 of the torque counterbalance 6,6, as more clearly shown in Figs. 7 and 8. By this structure, the operation of the pedals produces a swinging `movement of the outer vanes 72 about their pivotal connections 74.

The operation is as follows: Engine 30 produces rotation of the impeller 38, causing a flow of air through the rotating blades 4S. vIt will be observed that the impeller is of the mixed flow type, in which the air enters substantially axially, is deflected outwardly by means of the entrance cone 44, and enters the spaces between the blades 48 ina substantially radial direction. Theair, in passing through the impeller, is given a high velocity of flow, and discharges, by way of the impeller discharge 54, at a very high velocity in a direction substantially tagential to the airfoil skin 32. The discharge of the air may be radial, or may have a component in a peripheral direction, depending upon various factors such as the speed Aof, rotation of the impeller, and the rate of climb of the lift device. The reaction of the impeller blades on the air passing therethrough results in a torque about the vertical axis of the device, tending to produce a spin about this axis, as is common in helicopters. In order to counterbalance this spin, the deflector vanes 72 may be adjusted by means of the pedals 134 to provide a counterbalancing torque in the other direction. The high velocity air, discharging from the lower end of the skin 32, is deflected by the deflector vanes 72, producing an impulse in the direction desired. The pedals 134 may be actuated to adjust the deflector vanes 72 to orient the platform St) to enable the pilot to face any desired direction.

It is known in aerodynamics that the laminar ilow of a high velocity jet of air passing over a convexly curved surface, such as an airfoil, tends to pull away from the surface, resulting in a low pressure area between the air jet and the airfoil surface, producing an upward thrust or lift of said airfoil. Advantage is taken of this phenomenon by passing a high velocity jet of air over the convex surface of airfoil skin 32, producing an upward force on said surface. By varying the speed of the engine, the quantity and velocity of the air passng over the surface is also varied,` which provides a means to control the-upward lift of the lift device. Horizontal translation is effected by selectively adjusting the four thrust spoilers 56 by lateral maneuvering of the control rod 92 through the linkage described above Assuming that the curved surfaces 58 of the thrust spoilers 56 are in their neutral position as shown in Figs. land 2, that is, parallel to the contiguous surface 32, the thrust forces acting on the skin 32 are uniform, and the vertical axis of the lift device will assume a vertical position. Assume, for example, that it is desired to traverse the lift device horizontally, the control rod 92 is moved laterally in the proper direction, which movement swings the upper end of the rod in the opposite direction, and by means of the control links 126 and/or 122, produces a tilting of the opposed curved surface 5S connected to said links. Referring to Fig. 3, one curved surface 5S will be tilted to the position shown in broken lines, which will decrease the distance between the upper edge of said curved surface and the skin 32 and increase the distance between the lower edge and the skin, thereby providing a flow channel between the surface Sii and the adjacent skin 32 which increases in cross section from inlet to outlet. As shown by the broken arrows, a portion of the air passing over the skin 32 will be deflected away from the skin over the top of curved surface 58, which will result in a reduced lift over this portion of the airfoil surface 32. At the same time the curved surface 53 of the opposite thrust spoiler 56 will be tilted, by means of a control link 12d, through an equal angle, whereby the upper edge of the curved surface 58 Will be disposed farther from the adjacent skin 32, while at Athis point produces a reaction which is effective to cause a slightly greater lift on this side of the lift device.

From the foregoing, it is evident that the above-mentioned lateral movement of the control rod produces a decreased lift on one side of th airfoil surface 32 and an increased lift on the other side thereof, resulting'in a tilting of the upper end of the vertical axis. This tilting action resolves the upward thrust on the airfoil surface into two components: one a vertical thrust, producing a lift, and the other a horizontal thrust, producing horizontal translation. By proper lateral maneuvering of the control rod 90, the lift device may be moved in the desireddirection, and at any desired speed by rotation of the control rod. Stability against spin is assured by control through the pedals 134.

While in the example described above, the lift is obtained by passing a high velocity of air over the extrados of the airfoil surface, other fluids could also be used,

such as, for example, combustion products, steam, or

exhaust gases.

As indicated above, the surface 32 of the airfoil approximates a parabolic surface of revolution with a focal point close to the peak of the parabola. One of the means by which such a surface may be developed is shown in Fig. 9 in which a pair of base lines 144 and 143, at right angles, are laid out. The base line 144 is approxiamtely three times the length of base line 148. At the outer end of base line 144, a line 14S is drawn at an angle of 60 `:from the base line 144. At the upper end of base line 148 a line 146 is drawn parallel to line 144, and at an angle of 3 relative to the line 146 another line 147 is drawn. These lines 145 and 147 intersect at point 149. Line 145 between base line 144 and the point of intersection 149 is divided into l2 equal divisions numbered, l, 2, 3 l2, and similarly, line 147 is divided into l2 equal divisions between the base line 148 and the point of` intersection 149; The points l, l, 2, 2, 3, 3, ctc. ofthe lines 14S and 147 are interconnected by a series of straight lines, as shown and the points of intersection of lines l and 2, 2 and 3, 3 and 4, etc., are indicated by circles drawn around the points 150. A .smooth curve 152 is `drawn through the points 159, which represents a contour closely approaching a parabola. It is obvious that the contour may bedeveloped by other well known methods. Best results are-obtained when. the lower or discharge end of the airfoil surface 32 extends at an angle of 60 to the horizontal.

Although the lift device, in the preferred embodiment, has been shown as circular, it is evident that it may assume other forms, such as, for example, polygonal, elliptical, oval, etc.

Having fully described my invention it is to be understood that I do not wish to be limited to the details set forth in my invention to the full scope of the appended claims.

l claim:

l. A lift device comprising: an airfoil having a fixed convex surface with a central opening therein, an irnpeller comprising a disk having blades attached to a surface thereof, said disk having a convex surface and mounted for rotation in said central opening, whereby the disk forms a continuation of the convex contour of the airfoil and the blades discharge a gas at high velocity tangentially of said disk over the extrados of the airfoil; and power means to rotate said impeller.

2. A lift device as defined in claim l, in which the i-mpeller has an axial inlet and a radial outlet.

3. A lift device as defined in claim 2, in which the inlet is upwardly directed.

4. A lift device as defined in claim 2, in which th blades include shroulds to rotate therewith. 1

5. A lift device as deined in claim 2, including a cone in the impeller inlet to change the direction of iiow of incoming liuid from axial to radial.

6. A lift device as defined in claim 1, in which the airfoil has an extrados surface the cross section of which is generally the form of a paraboloid with the focal point close to the peak of the paraboloid.

7. A lift device as defined in claim 1, including a plurality of spaced, arcuate surfaces hingedly mounted adjacent the outer surface of the airfoil in spaced relation to the extrados of the airfoil surface; means to selectively actuate said surfaces to produce an unbalancing of the upward thrust and a consequent tilting of the vertical axis of the airfoil surface; and adjustable means, mounted to receive the effluent between said airfoil surface and an arcuate surface, to counterbalance the spin resulting from the torque applied to said uid delivery means.

8. A lift device as defined in claim 7, including a single control member, connected to the power means and the arcuate surfaces, t'o regulate the output of the power means and the position of the arcuate surfaces.

9. A lift device as defined in claim 1, including a plurality of spaced, arcuate surfaces, said arcuate surfaces having intrados and extrados contours corresponding to 8 the intrados and extrados contours of the -airfol adjacent the outer edge; and means for hingedly mounting said .arcuate surfaces on a horizontal axisY in spaced relation Vmediate the upstream and downstream edges, whereby the adjusting means moves the inlet and outlet edges of the arcuatersurfaces relative to the extrados surface of the airfoil to provide the different forms of flow channels.

References Cited in the tile of this patent UNITED STATES PATENTS 2,547,266 Hoglin Apri. 3, 1951 2,768,801 Bitner et al. Oct. 30, 1956 FOREIGN PATENTS 137,654 Sweden Oct. 14, 1952 691,627 France July 15, 1930

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