US1637432A - Lighter-than-air aircraft - Google Patents

Description

' 1,637432 1927' B. N. WALLIS ET AL LIGHTERrTHAN-AIR AIRCRAFT Fiied' Dec. 17, 1925 1,637,432 PATENT OFFICE; J

Patented Aug. 2, 19 27. c

UNITED STATES BARNES NEVILLE WALLIS AND CHARLES, DENNI STO N BURNEY, OF WESTMINSTER, LONDON, ENGLAND, ASSIGNORS TO AIRSHIP GUARANTEE'COMPANY, LIMITED, OF

" LONDON, ENGLAND. I

LIGHTER-THAN- Application filed December 17, 1925, Serial No.

, This invention relatesto lighter-than-air In "H! as is the case when an "aircraft. i I i I I Much attention has, in recent years, been devotedto the problem of increasing the speed of air-ships, and, in'order that this may be economically accomplished, it is desirable, to introduce devices for reducing their headresistance. The principal method of obtaining improvement in the latter respect has been to make the hull of the airship of a so-called streamline shape, and considerable data are now available showing the general form thatshould be fol-' lowed in designing the lines of thebody orhullof the airship or aerostat. I i

For example, it is known that a body having a ratio oi? overall length to maximim diameter of 4 or 5 to l will oiier as low a resistance to propulsion through the air as anyship yet produced, provided the following proportions are generally fmain .tained; (a That the head or front portion should be approximately two diameters long, ,at which distance fronrthe nose the maximum diameter of the body should occur, and

should consist of a semiprolate ellipsoid that is to saythe vsolid formed by the rotation of a semiellipse about its major axis and '(b) that the tail or after portion should-be ape proximately 2% or diameters longrheasured from the place at which it joins the ,head portion. I

Such a form'ha'ving been obtained, it is found,however, that the shape appears "to be "too sensitive to external disturbances whenreproduced on a full sized ship.

It must beunderstood that at the present time it is customary to locate the mainloads of lighter-than-air aircraft such as the control,;passenger, andengine cars atgvarious points along or project beyond "or aerostat they form protuberances which interfere with the streamline flow around and along the hull or body, and thusset' up,discontinuousflow and turbulence. I I I This turbulence is most-serious when originated in the region-of thehead portion, i i the cars, or other causes of turbulence,are situated forward ofthe maximum diameter of the ship. i Further, it is found that the lower the re sistance of the bare hull or body, the'more serious dosuch disturbances become so that beneath the hull, and as they, the contour of the airship AIR AIRCRAFT.

in the past it may even have been preferable to construct a hull actually having a higher head resistance in itself, in order that the total resistance of the ship when fitted with cars might be, in the aggregate, less than that of asensitive shape when fitted with an identical arrangement of cars.

According to the present invention the front part of an airship, or other lighterthanair aircraft of torpedo-like configuration, is kept, up to the maximum diameter thereof, free or substantially free of external protuberances, such as cars, struts, wiring,'etc. To this end the main loads, such the observation, passenger, and engine cars are either wholly located within the outer cover of the airship or aerostat so that they do not protrude beyond the contour thereof or else they are locatedabaft the imaxzmum diameter of the ship, where the tubulence set up is not of a serious nature.

rllternatively, a combination of these two methods may be employed, so that the ship or aerostat iskept free or substantially free of protuberances up to a point abaft the maximum diameter thereof. a i

It has been found that by adopting such an arrangement of the main loads and/0r external protuberances the total resistance is Very considerably reduced; it may in certain cases be reduced by as much as 30%. -Fur thermore, this disposition of the main loads within the external streamline or contour, or abaft the maximum diameterfo'f the airship or aerostat, also enables the most approved streamline configuration to be adopted, while retaining the advantages of reduced head resistance, sensitiveness to con trol and navigability which result from the use of a fine streamline shape.

In the case of a rigid airship the main protuberances, such as the observation or control car and the passenger and engine cars, may be located within the contour or outer streamline of the ship, or certain of the main loads, such as the observation and passenger cars, may. be located within the outer streamline of the ship, while the engine cars may be located abaft the maximum diameter of the airship inthe Zone of negative pressure." The ship may be of streamline con'figurationand have a length to diameter ratio of 4 or 5 to 1 or as may be found desirable. The nose of the ship up to the first transverse frame may itsell be I a rigid airship constructed according to the present invention.

Figure 2 is a cross section of part of one side of the airship the section being taken in the way of the coaches. c

Figureis a part sectional plan view of Figure 1 showing the front portion of the airship up to the maximum diameter theren is the outer cover or enveloping surface of the airship. B. B are the longitudinal girders and B E the transverse frames. C is the mesh wiring which encloses the bags the latter being locatedas is custonr ary between each pair of transverse frames B B, the mesh wiring being preferably of the kind described in English Patent No 233,020 in order to allow tangential loading to be resorted to. D is the mesh wiring on the face of each of the transverse frames, and E is cord netting located transversely of the airship between each pair of gas bags, the

cord netting being connected to the frames by flexible steel cables E E F, F are the coaches which are preferably suspended from the framework of the airship and have their parts constructed and arranged in the manner described in our co-pending English application No." 238,981. It will be observed that the coaches are located entirely within the streamline or outer enveloping surface A of the airship. G. G are corridors located on each side of the airship and establishing communication between a compartment H at the nose of the airship and the passenger coaches. It will be observed that staircases I, I are carried by the suspended coaches F, F and that the corridors G. G on each side of the airshipgive access to thesaid staircases. The; corridors G, G are preferably also suspendedfrom the framework of the airship in the manner described in the specification of our English Patent No. 233,021. The corridors G, G by which access is obtained to the passenger coaches F,

F extend beyond the coaches (see Figure l) was to allow the crew to have access to all parts of the airship, and additional passages may alsobe provided in the interior of the transverse frames as described in our English patent specification No. 233,021. The compartment H' at the nose of the airship not only allows the passengers to enter and leavethe airship through a transversely disposed corridor 71, (see Figure 3) which esta lishes communication between the exterior and the corridors G, G, but is also employed as an observation and control car; obser 'ation posts being pro *ided, for exampic at the points if, 7L1. In the arrangement shown, the compartment H is located between an auxiliary frame H situated between the nose of the airship and the first main transverse frame B The maximum diameter of the airship occurs at the point X X, and it will be observed that the only protuberances beyond the streamline or outer I envelope of the, airship are the engine cars L, L and the usual control fins K, K, and that these are located beyond the maximum diameter thereof. Consequently, the airshipup to the, maximum diameter thereof is kept entirely free of the usual external protuberances, such as the control or observation station, the coaches for the passengers and crew, and the engine cars.

The transyerse and longitudinal frames may be constructed in the manner described in our English Patent No. 233,021. Furthermore, and in order to avoid distortion of the contour or external streamline due to flapping of the outer cover, which flapping as is well known, results usually from deterioration in the dope used to stiffen the cover taut also has the advantage of ventilating the airship v without necessitating the use of external protuberances, while the gas pressure of the internal gas bags may also be relieved by valves which do not protrude beyond the contour or external streamline of the airship. I

llhat we claim and desire to secure by Letters Patent of the United tates is An airship comprising a front portion consisting of a semi-prolate ellipsoid approximately2diameters long at which distance from the nose the maximum diameter of the airship occurs, and areal portion which is approximately 2 or 3 diameters longineasured fromthe place where it is joined tothe front portion, said front portion up to the maximum diameter of the airship being free or substantially free from external protuberances.

BARNES NEVILLE WALLIS. onanrns DENNISTON simmer.

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