US2984439A - Auxiliary container - Google Patents

Description

y 1961 w. s. FLETCHER 2,984,439

AUXILIARY CONTAINER Filed Feb. 8, 1956 3 Sheets-Sheet 1 Fit-- BY 5 %7% ATTORNEY y 6 1961 w. s. FLETCHER 2,984,439

AUXILIARY CONTAINER Filed Feb. 8, 1956 3 Sheets-Sheet 2 INVENTOR )fimaz 5. 667Cf/57? ATTORNEYS y 16, 1961 w. s. FLETCHER 2,984,439

AUXILIARY CONTAINER Filed Feb. 8, 1956 3 Sheets-Sheet 3 c INVENTOR %/wzzz 6: 59mm ATTORNEYS United States AUXILIARY CONTAINER 22 Claims. (Cl. 244-130) This invention relates to auxiliary containers and more particularly to containers of stream-line configuration for external attachment to high speed craft, notably aircraft, wherein a portion of the container in the vicinity of attachment to the craft body is provided with a convergentdivergent configuration to reduce the sharp drag rise normally occurring in the vicinity of such attachment during passage through the transonic speeds.

The configuration of the container of this invention is applicable to many uses of external auxiliary containers in any craft capable of attaining high speeds approaching and surpassing sonic speed. The containers may be fuel tanks, refueling units, transportable storage tanks, radar unit tanks and other streamlined containers, although specific reference and disclosure herein will be made to fuel tanks, of the type that are carried below or at the tip of aircraft wings.

The present invention incorporates the teachings of my invention in Streamlined Auxiliary Fuel Tanks, disclosed in United States Patent No. 2,596,139 which are the most satisfactory external high-speed containers yet devised. Prior to the development of my basic tank configuration of the aforementioned United States patent, the standard Air Force tank was of tear drop configuration. That old configuration produced many undesirable flight characteristics such as (a) disrupting wing tank aerodynamic characteristics which adversely affected wing and aircraft characteristics; (b) creation of severe problems of aileron buzz leading to faulty control and aircraft destruction; poor dropping characteristics whereby dropped tanks frequently collided with the aircraft; (d) penalizing of airspeeds; (2) reduction of cruising range; and other undesirable characteristics. The tank disclosed in United States Patent No. 2,596,139 represented a divergence from the line of thought of all others concerned with the external tank problems and was primarily successful because the airflow pattern over the tank at high speeds was correlated with the high speed airflow characteristics of the wing to which the tank Was attached at the attachment junction. By properly designing the fore and aft sections of the tank to obtain an optimum over-all Mach number coefficient for the tank and inserting an aerodynamically neutral center portion in the tank, the prior adverse interactions between the tank and wing were to all intents and purposes eliminated. A feature inherent in the provision of an aerodynamically neutral center portion was the extremely useful aspect of variations in length of the center portions to enable expansion of tank volume yet retaining the desirable relationship of the wingtank aerodynamic characteristics.

The foregoing factors are reiterated herein because of their importance in a successful high-speed tank configuration and because certain phases of this invention constitute improvements over the expansible nature of my prior tank. As the reduction from potbellied aerodynamic shapes to a neutral cylinder, in the vicinity of the airfoil (wing) made possible the approach to sonic and transonic speeds with tanks attached to wings, now the atent ice cavitation of the cross section of the tank in the vicinity of said airfoil (wing) makes possible entry into supersonic speeds by provision of an expansion space for shock Waves in airflow as aerodynamically required.

Furthermore the invention herein disclosed can be incorporated as an auxiliary unit or as a conversion unit that will enable transonic tanks, of which my prior patent is exemplary, to be changed to supersonic tanks by inserting a special center section. The tank of my prior patent, thus modified still retains its expansible nature by use of aerodynamically neutral mid portions between the supersonic section and the fore and aft sections.

A development by Richard T. Whitcomb at the Na tional Advisory Committee for Aeronautics, recently made publicly available, involves, among other things, the concept of narrowing an aircraft fuselage where it joins the wing to cut down the drag that occurs at supersonic speeds. This concept is termed Area Rule and has been successfully applied to two military aircraft. Concerning determination of Area-Rule concept aspects, reference can be made to N.A.C.A. Report No. 1273A Study of the Zero-Lift Drag Rise Characteristics of Wing- Body Combination Near the Speed of SoundRichard T. Whitcomb, 1956supersedes N.A.C.A. R.M. L52H08- August 1, 1952. Area Rule is a mathematical concept for calculation of cross sectional area changes in a basic airplane to reduce inter body interference on airflow. This cross-sectional area change is primarily realized in reduction of the fuselage area immediately adjacent the wing to fuselage joinder, and takes into account all of the fixed aircraft structure.

Although the invention disclosed in Patent No. 2,596,139 is basically essential in all details for tanks that will be subject to supersonic speeds, the present invention constitutes an improvement by incorporating cross-sectional area reduction in a container for attachment to the exterior of an aircraft preferably under the wing or at the wing tip. It is particularly applicable to auxiliary attachment of external jettisonable containers to a basic airplane which has been balanced by the Area Rule concept. The improved container is provided with streamlined nose and tail portions, the nose being basically formed from an ellipse or conoidal section and the tail being formed of a section of conoid plus a cone. Between the nose and tail portions the container may be provided with an aerodynamically neutral section of cir cular or oval cross-section except for that portion of the tank immediately adjacent the wing which, from front to rear, will have a slight convergent-divergent configuration providing a pinched or wasp-waist effect to reduce the sharp increase in drag occurring at transonic speeds from interbody interference. The Area Rule mathematical concept can be used to calculate the cross-sectional area reduction at the convergent-divergent portion.

This portion of the tank adjacent the wing which will be termed the transonic section, can have a cross-section that is substantially circular, ovaloid or lenticular, the exact configuration being governed by the specific aircraft installation, manufacturing and shipping considerations. In actual structure my improved tank can be made wholly integral; or with nose and tail portions separable from a mid-section that will include the transonic section; or with nose and tail portions separable from a midportion that can be assembled from various length neutral section(s) and an appropriate transonic section; or in other manners as will become apparent. Assembled sectional tanks can be integrally joined with externally smooth joints or the sections may be releasably joined in any suitable fashion, e.g., that illustrated and described in my United States Patent No. 2,686,609.

Accordingly, a primary object of my invention is to provide an auxiliary container, for attachment to a high speed body having an intermediate portion thereof provided with a longitudinal convergent-divergent configuration. A related object resides in providing an auxiliary container having a streamlined nose and tail portion with the portion therebetween including a longitudinal convergent-divergent configuration.

Still another object resides in providing an auxiliary container for attachment to the wing of an aircraft wherein the container nose and tail portions are streamlined, the portion therebetween has provision for attachment to the aircraft wing and the extent of container adjacent the wing is provided with a longitudinal convergent-divergent configuration.

A further object resides in providing a transonic tubular section, having a convergent-divergent configuration from adjacent one end to adjacent the other end, for use in at least a part of the mid-portion of an aircraft auxiliary container having separable streamlined nose and tail portions with provision for the mid-portion to be connected therebetween to form a closed container.

A still further object resides in providing an expansible, transonic, auxiliary container for aircraft having separable nose and tail portions and a mid-portion consisting of at least one tubular section having a convergent-divergent configuration and at least one aerodynamically neutral tubular section, the nose portion, mid-portion and tail portion being joined to provide a closed container.

Another object resides in providing a streamlined auxiliary aircraft container having a part of its mid-portion formed with a fore and aft convergent-divergent configuration the varying cross-sections of which can be circular, ovaloid, lenticular or any combination thereof.

Still another object resides in providing a streamlined, auxiliary aircraft container having nose and tail sections provided with streamlined contours, the nose being developed basically from an ellipse and the tail being developed basically as a truncated conoid terminating in a cone, and a mid-portion having at least two sections; the nose section, all sections of the mid-portion and the tail sections being joined to provide a closed container, and one of said mid-portion sections being of convergentdivergent configuration and at least one other mid-portion section having a constant, aerodynamically neutral crosssection whereby its length may be varied without greatly affecting the tank overall Mach number. In conjunction with this object the mid-portion can consist of two aerodynamically neutral sections, one between the transonic section and the nose section and the other between the transonic section and the tail section.

Further novel features and objects of this invention will become apparent from the following detailed description and the appended claims taken in conjunction with the accompanying drawings showing a preferred embodiment thereof, in which:

Figure 1 is an illustration of a basic streamlined auxiliary container having a configuration as disclosed and described in my United States Patent No. 2,596,139, the neutral mid-portion of which can be expanded to desirable lengths by insertion of one or more elongate drum sections;

Figure 2 illustrates a tank derived from the basic configuration shown in Figure 1 and in which the mid-portion includes two drum shaped aerodynamically neutral sections, that can be of various lengths, and a convergentdivergent transonic section;

Figure 3 is a section view taken on lines 3-3 of Figure 2 schematically illustrating a circular cross-section, of a coaxially symmetrical transonic tank section;

Figure 4 is a section view similar to Figure 3 schematically illustrating an oval cross-section of another embodiment of a transonic tank section;

Figure 5 is a section View similar to Figure 3 schematically illustrating a lenticular cross-section of a further embodiment of a transonic tank section;

Figure 6 is a section view similar to Figure 3 schematically illustrating an eccentrically olfset circular crosssection of a still further embodiment of a transonic tank section;

Figure 7 is a perspective view of a supersonic aircraft provided with wing tip tanks having a configuration with a transonic section similar to that of Figure 2 disposed adjacent the wing to tank interconnection;

Figure 8 illustrates a tank with a transonic portion on the side and to be attached to a wing substantially midway of the tank length;

Figure 9 illustrates the transonic portion shifted forward on the tank for installations where the wing tip attachment occurs at the forward end of the tank;

Figure 10 illustrates the transonic portion shifted to the rear of the tank for installations where the wing tip attachment occurs at the aft end of the tank;

Figure 11 is a schematic section view illustrating attachment of the transonic portion of a tank to the tip of a wing by means of an indented tip recess in the transonic section;

Figure 12 is a schematic section illustrating a flush attachment of the transonic portion of a tank to the tip of a wing with a filleted hanger as disclosed and described in United States Patent No. 699,908;

Figure 13 schematically illustrates a manner of hanging the tank with the transonic section located under the wing;

Figures 14 and 15 illustrate a pinched waist applied to the top quarter section of a tank on inner side, adjacent the wing tip, Figure 14 is illustrating a recessed Wing tip installation and Figure 15 illustrating a filleted flush wing tip installation; and

Figures 16 and 17 illustrate one means of generating an ellipsoidal conoidal nose section for a container by use of a section of a basic ellipse.

With reference to the drawings, there is shown in Figure 1 a basic container form 20, hereinafter termed a tank, constructed in accordance with the teachings in my United States Patent No. 2,596,139. Tank 20 has a conoidal nose portion 22 constructed from a semi-elliptical section of a basic ellipse having a minor axis in the vicinity of 27% or less of its major axis. Any elliptical section of such a basic ellipse, rotated about a line parallel to the major axis of the ellipse and intersecting the elliptical section will generate a conoid of semi-elliptical longitudinal contour. This is illustrated in Figures 16 and 17 (Sheet 3), wherein Figure 16 is half of an ellipse whose minor axis A is approximately 27 percent of the major axis 2B. A section E0 of such a basic ellipse can be rotated about an axis C, parallel to B to generate the conoidal form illustrated in Figure 17 that can be used under certain design conditions as the nose section on a high speed tank. By proper calibration a nose section of conoidal form can be constructed with circular, oval or lenticular cross-section in which no longitudinal semielliptical plan form will have a minor axis value exceeding 27% of the major axis value. Phantom lines 23, in Figure 1 illustrate an optional nose cone that may be used if desired, although it has little or no effect upon airflow. The tail section 24 of the basic tank is preferably conical with a forward portion of frusto conoidal form enabling a smooth transition from the intermediate part of the tank into the conical part. By providing the nose and tail sections with different optimum Mach number coefficients, as dictated by increasing velocity of the air passing lengthwise over the tank, an overall average Mach number coeflicient is attained for the tank which is an optimum value for the particular installation.

The basic tank 20 with nose 22 and tail 24 uses an aerodynamically neutral, drum-like, center section 26 of desired length to assure that airflow between tank and the adjoining wing is relatively undisturbed. The open end of the nose section 22 is shaped to match the end of and fair smoothly into the drum section 26 which a constant cross-section matching the open end of the nose section, throughout its length. The aft end of the longitudinal seam X on the bottom or side.

drum section 26 matches the forward open end of and fairs smoothly into the tail section 24. Drum section 26 of such prior art tanks can be made of one or more coaxially coextensive drum sections, the length of each of which can be varied to increase the neutral section for different wing chord lengths according to the specific spanwise location of a tank on a specific wing of a specific aircraft and to increase tank capacity. Note, the .drum section may be fabricated to include a portion of the transition into the nose or tail configuration but such shapes will tend to complicate manufacturing, storage and shipping considerations.

In Figure 2, a supersonic tank 30 uses a nose section 32 and tail section 34 from the basic tank 20'. Two aerodynamically neutral drum sections 36 and 37 are coextensively fastened, one to the nose 32 and one to the tail 34. Fastened between the two drum sections 36 and 37. is a transonic mid-section of longitudinally convergent-divergent configuration, completing the enclosed streamlined tank. Tank hangers 39, fuel and pressure fittings, and other auxiliary fittings are included in the transonic mid-section 38 to provide attachment to the wing of an aircraft, either at the tip or under the wing. The length of the convergent-divergent portion will be determined by installation on each specific aircraft model. It is desirable that the point of initial convergence be substantially at the most forward position where wing and tank are in close proximity. In wing tip installations, Figure 7, this location is substantially at the intersection of the leading edge of the wing with the tank body and in under wing installations this location is substantially vertically below the leading edge of the wing. The point of final divergence will be substantially at the most aft position where wing and tank are in close proximity. In wing tip installations this latter location is substantially at the intersection of the trailing edge of the wing with the tank body and in under wing installations this latter location is substantially vertically below the trailing edge of the wing. It is proposed to construct this convergent-divergent configuration in accord with the Area Rule mathematical concept and to thereby substantially reduce the sharp drag rise at the juncture of wing and tank as the airflow at the juncture passes the transonic speeds.

Figure 5, varied to provide convergence and divergence, will be the most desirable. However, the expense of manufacturing will probably dictate alternative configurations such as the circular configurations of Figures 3 or 6 which will provide the greatest strength to weight factor. The oval sections of Figures 4 and 13 are proposed primarily for under wing installations but the circular symmetrical, lenticular and eccentric configurations of Figures 3, 5 and 6 respectively could also be applicable to such underwing installations.

Narrow integral cylindrical portions 40 and 41 can be provided at each end of the transonic section 38 to enable a feasible structural joint for connection with adjoining tank sections, e.g., in the manner illustrated in my United States Patent No. 2,686,609 or in copending application Serial No. 459,232 filed September 30, 1954, now US. Patent No. 2,876,923 by P. W. McLane et al. for Tank Construction. In addition, the transonic section 38 may be made of several units separable at the midpoint and can include a releasable longitudinal seam joint to enable ease in sectional nesting for compact shipping and storage in disassembled condition. Transonic sections constructed in accordance with the cross-sectional forms of Figures 4, 5 and 6 will lend themselves more readily to a longitudinal releasable seam joint at positions marked X than will the coaxially symmetrical circular transonic section of Figure 3. The latter would require a specially contoured longitudinal seam. A tank with a transonic section as illustrated in Figure 4, when mounted underwing could have the With tranfionic sections as in Figures 5 and 6, the longitudinal installations, will be at top or installations will preferably be seam X, in underwing bottom and in wing tip outboard.

Figure 8 is somewhat similar to Figure 2, both illustrating a supersonic tank with the transonic section between two aerodynamically neutral drum sections however, the transonic section 42 in Figure 8 has a cross section similar to that of Figures 4, 5, l1, 12 or 13. In each instance any of the drum sections 36 and 37 or 36 and 37' can be interchanged with longer drurn sections to increase tank capacity and retain designed tank center of gravity. Alternatively the two drum sections 36 and 37 of Figure 2 and 36 and 37' of Figure 8, or a single drum section could be placed at one end of the transonic section 38 or 42 to shift the tank center of gravity as desired for specific aircraft installations.

As an alternative to obtaining tank configurations by assembled separate sections a tank may be fabricated as illustrated in Figure 9 where the mid portion 50 has a transonic convergent-divergent section 52 disposed forward on the tank and the forward end .54 of the midportion includes a part of the transition into an ellipsoidal nose shape. In this instance the aft end 56 of mid-portion 50 includes an integral aerodynamically neutral cylindrical part that can be varied in length (within design center of gravity limits) to provide added capacity. This style of tank is for a forward wing tip attachment installation.

In Figure 10 a tank is illustrated with provision for an aft wing tip attachment installation. Note the midportion 60 has its transonic section positioned aft and the aft end 62 includes a frusto-conoidal fairing that provides attachment for a tail conical section 64, while the forward part 66 of the mid-portion includes an aerodynamically neutral section for increased capacity. In such fixed mid-portion embodiments the specific tank length and capacity are essentially limited to center of gravity tolerance of the airplane involved because there is no provision for adding equal capacity drum sections at both front and rear of the transonic attachment position. Note, a drum section can be added only at the front of the mid-portion in the tank as illustrated.

Various satisfactory wing tip hangers are suitable for use in fastening the tank to the wing tip at the transonic section. Two such hanger embodiments are schematically illustrated in Figures 11 and 12. Figure 11 illustrates the use of a recessed well 70 provided in the midportion of a tank 72 and extending substantially the length of the transonic section 74. Well 70 includes tank hangers and fuel fittings, etc. that connect to quick disconnect fuel, pressure and other fittings: in an aircraft wing tip. The recess 70 is contoured to fit over the end of a wing tip 76, and therefore will be specifically shaped for substantially each aircraft model installation. The wing tip fit need not be snug, as adjustable braces are utilized to fit the tank to the well and can be arranged to fill any clearance.

An alternate mode of wing tip attachment, schematically illustrated in Figure 12, does not require a recess for the wing tip but enables use of the flush tip installation with hanger fillet between the wing and tank as disclosed in United States Patent No. 2,699,908.

Figure 13 illustrates one transonic cross-section configuration of a tank for an under wing installation. Note that tank 82 in this installation is arranged with transonic convergent-divergent portions 84 and 86 on each side of the tank to enable dissipation and reduction of the transonic shock wave emanating from the areas of the Wing 88 and tank 82 that are immediately proximate the wingtank attachment. As before noted, tanks with transonic sections as illustrated in Figures 3, 4, 5 and 6 can also be used in under wing installations to provide convergentdivergent portions on each side of the tank.

Figures 14 and 15 respectively illustrate wing tip installations of the recessed well and flush installation types somewhat similar to Figures 11 and 12, however, the transonic sections 90 and 90' have the convergent- divergent portions 92 and 92 confined to the top quarter section of the tank adjacent the wing tip 94 and 94, the lower quarter sections 96 and 96' adjacent the wing tip retained the cylindrical aerodynamically neutral configuration of the remainder of the mid-section.

From the foregoing description it is understood that this invention encompasses the use of a longitudinally convergent-divergent portion in an auxiliary container to enable reduction of drag forces developed as the container is moved through the transonic speed zone. As particularly applicable to aircraft the convergent-divergent portion of the container is specifically located proximate the attachment position, e.g. in wing tip installations the convergent-divergent portion extends throughout a major portion of the tip chord length. The transonic container section is adaptable for use in converting presently used high speed aircraft containers, such as fuel tanks, into a transonic container as hereinbefore described. The invention has been described as, and is preferably applied to the specific basic streamlined high speed container disclosed herein.

The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by United States Letters Patent is:

1. For use in combination with an aircraft member, a supersonic container of elongate form having a closed end streamlined nose portion, a closed end streamlined tail portion and an intermediate longitudinally convergent-divergent portion of a finite length, said latter portion having a smooth gradual cross sectional change substantially the entire extent of its length intermediate said nose and tail portions and means on said container enabling fastening of the container to said aircraft member with said convergent-divergent portion adjacent the member.

2. For use in combination with an aircraft airfoil member, a supersonic container of elongate form having closed end streamlined nose and tail sections and an elongate section intermediate the nose and tail sections having means attached thereto adapting the container to be fastened to the airfoil member, a portion of said intermediate section which will be disposed proximate the airfoil member having a longitudinal gradual convergentdiver-gent external configuration between its ends adapted to dissipate transonic shock waves occurring at transonic speeds in the vicinity of the airfoil-container junction when the container is secured on an airfoil member and thereby reduce transonic drag.

3. For use in combination with an aircraft airfoil member, a supersonic container of elongate form having closed end streamlined nose and tail sections and an intermediate section having means attached thereto and adapted to be fastened to the airfoil member, a first portion of the intermediate section, which is adapted to be disposed proximate said airfoil member, having a longitudinal gradual convergent-divergent external configuration throughout its length and other portions of said intermediate section disposed between said first portion and said nose and tail sections having a longitudinally aerodynamically neutral configuration.

4. In combination with an aircraft airfoil member, an external detachable supersonic container of elongate form having closed end streamlined nose and tail sec tions and an elongate section intermediate the nose and tail sections having means secured thereto enabling the container to be fastened to said airfoil member, a portion of said intermediate section which will be disposed proximate the airfoil member having a longitudinal gradual convergent-divergent external configuration between its ends adapted to dissipate transonic shock waves occurring at transonic speeds in the vicinity of the airfoilcontainer junction and thereby reduce transonic drag.

5. The combination as defined in claim 4, wherein said airfoil member is a wing, said intermediate section of said container has a longitudinally disposed recess in addition to said gradual convergent-divergent configuration shaped to receive the tip of said wing, said fastening means secured to said intermediate section are dis posed in said longitudinal recess, and said portion of said intermediate section extends at least equal to the distance from the leading to trailing edge of the wing tip to which the container is fastened.

6. The container as defined in claim 2 wherein said portion of said intermediate section has an oblong crosssectional configuration.

7. The container as defined in claim 2 wherein said portion of said intermediate section has a lenticular crosssectional configuration.

8. The container as defined in claim 2 wherein said portion of said intermediate section has a circular crosssectional configuration.

9. For use in combination with an aircraft airfoil member, a supersonic container of elongate form fabricated of independent sections comprising: a nose section formed as an ellipsoid; a conoidal tail section with a conical tip; a drum shaped center portion coextensively connecting said nose and tail sections consisting of an intermediate transonic section including a longitudinal smoothly changing and gradual convergent-divergent external configuration, at least one aerodynamically neutral section coextensively connected between said nose section and said transonic section and at least one aerodynamically neutral section coextensively connected between said tail section and said transonic section; and means on said transonic section adapting the container to be fastened to the airfoil member.

10. For use in combination with an aircraft airfoil member, a supersonic container of elongate form fabricated on independent sections comprising: a conoid nose section formed as an conoidal generated from an elliptical section of a basic ellipse whose minor axis is approximately 27 percent or less of its major axis; a tail section comprising a truncated conoid terminating in a cone; a drum shaped center portion coextensively connecting said nose and tail sections consisting of an intermediate transonic section including a longitudinal smoothly changing and gradual convergent-divergent external configuration, *at least one aerodynamically neutral section coextensively connected between said nose section and said transonic section and at least one aerodynamically neutral section coextensively connected between said tail section and said transonic section; and means on said transonic section adapting the container to be fastened to the airfoil member.

11. A streamlined container of sectional fabrication comprising: a nose section formed as an ellipsoid generated from an elliptical section of a basic ellipse whose minor axis is approximately 27 percent or less of its major axis; a. tail section comprising a conoid; and a drum shaped center portion of at least one section coextensively connecting said nose and tail sections, a portion of said center portion having a longitudinally smoothly and gradual convergent-divergent external configuration throughout its extent.

12. A container as defined in claim 11 wherein said at least one section is comprised of at least two independent units joined approximate the transition between convergence and divergence.

13. A plurality of independent sections secured together to provide a closed high-speed container for use 9 with a separate carrying member comprising: a high speed divergent nose section with a closed forward end; a convergent high speed tail section with a closed rear end; a tubular intermediate portion connecting said nose and tail sections and comprising at least one portion of aerodynamically neutral configuration and at least one portion of longitudinal smoothly and gradual convergent-divergent external configuration throughout its extent; and attachment means fixed to the convergent-divergent portion of said intermediate portion for fastening said container to the separate carrying member.

14. A plurality of independent sections secured together to provide a closed high speed container comprising: a high-speed divergent nose section with a closed forward end; a convergent high speed tail section with a closed rear end; a tubular intermediate portion connecting said nose and tail sections and comprising at least one independent section of aerodynamically neutral configuration, and at least one section including a longitudinally smoothly and gradual convergent-divergent external configuration throughout its extent with means at each of its ends to coextensively match and fair into the configuration of each adjoining section.

15. For use in a sectional high speed streamlined container having separable nose, tail and aerodynamically neutral center sections, a transonic center section for insertion between said nose and tail sections comprising: a tubular section including an intermediate portion wtih a longitudinally smoothly and gradual convergent-divergent external configuration throughout its extent with end portions adapted to coextensively match and fair with the other container sections.

16. A container transonic center section as defined in claim 15 wherein said intermediate portion has an oblong cross-sectional configuration.

17. A container transonic center section as defined in claim 15 wherein said intermediate portion has a lenticular cross-sectional configuration.

18. A container transonic center section 'as defined in claim 15 wherein said intermediate portion has a circular cross-sectional configuration.

19. A container transonic center section as defined in claim 15 comprising at least two independent units joined approximate the transition between convergence and divergence.

20. A streamlined container of elongate form having a streamlined nose and tail and a longitudinal gradual convergent-divergent portion intermediate said nose and tail, said convergent-divergent external configuration portion having a cross-sectional configuration throughout, a major peripheral portion of which is disposed the same distance from the longitudinal axis of the container at any point through the length of said portion.

21. A streamline container of elongate form for use with a high speed member having: a streamlined nose and tail section and a section intermediate said nose and tail sections, said intermediate section being provided with a longitudinally convergent divergent external configuration with a smooth and gradual cross-sectional change through such configuration, and means on said intermediate section adapting the container to be releasably fastened to the high speed member.

22. A supersonic container for use with a member capable of transonic speeds, said container having a successive divergent, parallel, gradually and smoothly convergent, gradually and smoothly divergent, parallel and convergent confining wall external configuration from one end to the other, and means enabling the container to be releasably fastened to the member capable of transonic speeds.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Aviation Week, vol. 63, No. 11, Sept. 12, 1955.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 2,984 ,439 May 16, 1961 Wendell s.- Fletcher It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent. should read as "corrected below.

Column 4, line 24, for "699,908" read 2,699,908 line 74, before "8" insert has column 8, line 44, for "on" read of same line 44, for "conoid" read conoidal same column 8, line 45, for "conoidal" read conoid column 9, line 7, and column 10, line 2, for "longitudinal", each occurrence, read longitudinally same column 10, line 3, after "divergent" insert external configuration line 4,

strike out "external configuration'h Signed and sealed this 17th day 01 October 1961.,

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. LADD Attesting Officer 9 Commissioner of Patents USCOMM-DC

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