US1837901A - Arrangement for reducing losses of flow in conjunction with media flowing relatively to resting or moving walls - Google Patents

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1,837,901 JUNCTION WITH ALLS Dec. 22, 1931. H. FCTTINGER ET AL ARRANGEMENT FOR REDUCING LOSSES OF FLOW IN CON MEDIA FLOWING RELATIVELY TO RESTING OR MOVING W Filed Jan. 7, 1950 Patented has. 22, 1931 I PATENT oFF1ca FOEETINGER, OF BEBLIN-WILMERSDORF, GERMANY, AND KURT ram, 01

DANZIG-LANGFUHE, FREE STATE OF DANZIG- GEMEVT FOB.BEDU OIN G LOSSES FLOW IN CONJUNCTION WITH manna BLOWING i TIVELY TO RESTMG OR MOVING WALLS Application filed January 7, 1930, Serial No. 419,128, and in Germany January 8, 1929.

It is a known fact that with media flowing or streaming relativelytp resting or moving diminished in such cases.

We now have found, that these drawbacks, particularly the separation of the flow or stream from the wall, may be avoided, if

"short subdivided guiding surfaces arranged in steps like sails are provided beside a passing, uninterrupted, sharply bent wall causing abruptly enlarged stream lines under ordinary working conditions. Careful investigations have shown, that the disposition of such subdivided guiding surfaces arranged in steps renders it possible, to wholly or partly'obviate the drawbacks otherwise caused by the abrupt enlargement of the stream lines,

viz. the formation of eddies or cavitations.

This inventive idea may be applied not only to hollow bodies passed by fluids, such as suction pipes, quarter bends, runners and guide-wheels of turbo-machines, including propellers for water, gas' or steam, .ventilation heads or hoods on ships and other vehicles on land, in the airand in the water, river and pipe bends, river and pipe enlargements, all kinds of difi'users with straight or bent axis, e. g. difiusers for coal-dust firings, chimneys,

exhausters. Venturi tubes; but also to bodies I round which the media or fluids flow, such as for instance for reducing the deleterious flow pressures upon isolated buildings, e. g. ships super-structures, halls etc., as well as to ships bodies, aeroplane bearing surfaces, aeroplane bodles, motor cablns. airship bodies, ra1lway posed at or beside sharp bends, where under normal working conditions an abrupt enlargement of the stream lines would be caused near the walls. In connection herewith it is of advantage, that the distance between the parts of the subdivided guiding surface arranged in steps like sails and the wall diminishes in the direction of flow of the medium, in other words, that with a body, such as an aeroplane,

a motor car or a ship, passing through a subdivided guiding surface situated most in front has a greater distance from the neighbouring wall than that part of said guiging surface which is situated more be- 1n It is. known that the sails subdivided and arranged in steps in the usual manner rove to be advantageous if compared wit undivided sails. This perception was the reason for creating the well known split wings of aeroplane, where, to say so, one single uninterrupted, passing stream line body is separated or dissolved into several part wings medium such as air or water, that part of the following one another in the direction of stream and adjustable with respect to one another if desired. In contrary thereto, ac-

cording to the present invention the bent 1 wall passing from the front to the rearend of the body remains undivided, special subdivided guiding surfaces being arranged be- 7 side and near said wall.

.In the drawings a few examples of performance or forms of application of the obj ect of the invention have been illustrated, in which I Fig. 1 shows diagrammatically in section a wall surface withaccentuated or sharp curvatures, e. g. the one wall of a curved tube,

Fig. 2 a plan view thereto,

Fi 3 a sectionalview of a curved or bent tube eing simultaneously enlarged,

- Fig. 4 the diagrammatic profile section through a hollow aeroplane wing,

Fig. 5 the diagrammatic representation of a railway car in lateral view'and Fig. 6 a plan view thereto.

In Figs. 1. and 2 a continuous wall is shown, having two sharp or accentuated points of curvature of the characterized na= ture at B and G. Beside the points of curvature B and C the Short, sudbivided guiding .however, may

.parts.

surfaces D and E arranged in steps like sails have been disposed, which in the present example consist of two curved, partly overlapping surfaces arranged beside the wall A at a short distance from one another. The direction of flow or stream of the surrounding medium is indicated by the arrow F. The gap between the two surfaces D and E takes in this case a course under an angle of 90; the angle, however, may also be a different one.

The wall surface A may represent for instance one of the limiting walls of a curved tube or the like, which would then be faced by a second wall not shown. The wall A,

also represent anotherv resting wall, e. g. that of a building or the like, or else a wall moving against the medium, p the wall of a power driven vehicle or the In the example of Fig. 3, where a curved and simultaneously enlarged tube G is shown, subdivided guiding surfaces I, K, L arranged in steps like sails have been provided within the tube at the point of curvature H. In the example of execution shown the outer guiding surfaces I and L are subdivided into three parts, whereas the intermediate guiding surface K is only subdividedinto two The direction of flow is indicated by the arrow F.

In the example of Fig. 4 where the profile section through a hollow aeroplane wing M is shown, the subdivided guiding surfaces P and Q, respectively have been disposed beside the'curvatures N and O on the upper face of the aeroplane wing, the direction of the air flowing relatively thereto, being indicated by the arrow F In the example of Figs. 5 and 6 subdivided guiding surfaces T and U, extending along the whole height of the car-body V, have been disposed at the front corners R, as well as at the rear corners S. Correspondingly subdivided guiding surfaces may also be arran ed at the horizontal front and rear-edges of the car-body, i. e. subdivided guiding surfaces, the axis of which is likewise placed horizontally. The direction of motion is indicated by the arrow W. A corresponding arrangement is also possible with locomotives, power-driven vehicles and the like.

/ Having now particularly described and ascertained the nature of our said invention, what we claim is 1 1. A device for reducing the stream losses in conjunction with media streaming relatively to resting or moving walls, short guiding surfaces arranged opposite to sharply bent portions of said walls, said short guiding surfaces being subdivided like sails in such a manner that the indicated members of each subdivided guiding-surface will overlap one another for a short part only of their length and will be at a relatively short distance only from one another compared with their length. 1

2. A device for reducing the stream losses in conjunction with media streaming relatively to resting or moving walls, with a body around which a medium is flowing, undivided sharply bent walls on said body, short guiding surfaces arranged opposite to sharply bent portions of said walls, said short guiding surfaces being subdivided like sails in such a manner that the individual members of each subdivided guiding surface will be arranged in steps with respect to one another, overlapping one another for a short part only of their length and will be at a relatively short distance only from one another com pared with their length.

3. A device for reducing the stream losses in conjunction with media streaming relatively to resting or moving walls, short guiding surfaces arranged opposite to sharply bent portions of said walls, said short guiding surfaces being subdivided like sails in such a manner that the individual members of each subdivided guiding surface will oversails in such a manner that the individual members of each subdivided guiding surface will be arranged in steps with respect to one another, overlapping one another -for less than half their length only,and will be at a distance from one another which is not more than half their length. Y

5. A device for reducin the stream losses in conjunction with media streaming rela-' tively to resting or moving walls, short guiding surfaces arranged opposite to sharply bent portions of said walls, said short guiding surfaces. being subdivided like sails in such a manner that the indicated members of each subdivided guiding surface will overlap one another for a short part only of their length and will be at a relatively short distanceonly from one another compared with their length, that of said individual members which is the headmost against the direction of the streaming medium being arranged in the greatest distance from said sharply bent portion belonging thereto.

6. A device for reducing the stream losses in conjunction with media streaming relatively to resting or moving walls, with a body around which a medium is flowing, undivided, sharply bent walls on said body, short guiding surfaces arranged opposite to sharply bent portions of said walls, said short guiding surfaces being subdivided like sails in such a manner that the individual members of each subdivided guiding surface will be arranged in steps with respect to one another, overlapping one another for a short part only of theirlength, and will be at a relatively short distance only from one another compared with their length, that of said individual members which is the headmost against the direction of the streaming medium being arranged in the greatest distance from said sharply bent portion belonging thereto.

In testimony whereof we have hereunto set our hands.

DR. HERMANN FOTTINGER. KURT FREY.

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