US2466684A - Radiator core - Google Patents

Description

April 12, 1949. H. w. CASE RADIATOR CDRE Filed April 18, 1945 1M 'liN 10R. b29040 #461485 Patented Apr. 12,1949

UNITED STATES PATENT OFFICE 2,466,684 n RADIATOR CORE Harold W. Case, Dayton, Ohio Application April 18, 1945, Serial No. 589,005

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 2 Claims.

-'Ihe invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to radiator core tubes and particularly to the tubes of radiator cores through which the cooling medium travels at extremely high speed, as it does for instance in the radiators of high speed aircraft, the improvement in subject invention being particularly concerned with the mounting sleeves of such tubes.

In my prior Patent No. 2,325,036, of July 27, 1943, I show and describe a radiator core made up of Venturi-shaped tubes, the Venturi shape being such that if a section is taken through the core on a plane which passes through the axis of two adjacent tubes, the section formed by the lower surface of the upper tube and the upper surface of the lower tube will be substantially that .of a symmetrical airfoil. This section varies from a true symmetrical airfoil in that the chord line of the upper contour is separated slightly from the chord line of the lower contour.

The mounting sleeves of the tubes disclosed in the prior patent supra, however, were so made and formed as to leave relatively blunt ends front and back on the airfoil shape above mentioned, thereby retarding the entry and exit of the airflow through the core.

It is therefore an object of this invention to substantially follow the teaching in the prior patent, supra, insofar as the tubes are of such Venturi shape that the section formed by the lower surface of the upper tube and the upper surface of the lower tube follows the form .of a true symmetrical airfoil. In the section of the present invention the chord lines of the upper and lower contours are one and the same. It is also the object of this invention to so alter and improve the mounting sleeves that the said true symmetrical airfoil shapes come to substantially a sharp edge both front and back, to the end that there may be both a smoother entry and a smoother exit forthe cooling air passing through the radiator whereby the volume of air passing through the core in a given time will be increased.

More generally the object of my invention is to provide a radiator core tube which will ofler the smallest possible resistance to'the passage of air at a given speed, by so forming the tube that the air moving through the tube will be passing around a true symmetrical airfoil section which has characteristics proportionate to the speed for which the radiator is designed.

Still another object is to so fashion the mounthad to the drawing, wherein:

Fig. 1 is an axial section through one of my im proved radiator core tubes.

Fig. 2 is an end view of a section of a radiator incorporating a plurality of these tubes.

Fig. 3 is a cross-sectional elevation through a row of tubes taken on the line 3-3 of Fig. 2.

v Fig. 4 is a transverse section taken at 4-4 of Fig. 3.

Like reference characters refer to like parts Lhroughout the several views.

The axial cross section Fig. 1 shows a single tube l of Venturi shape, the throat of which,.in the instant case, is at l3, which may be somewhere near the midway point of its length. The cross section of the main portion of the tube shown is circular both outside and inside but of varying dimensions throughout the length, while the end sleeves 2 are hexagonal on the outside a and of uniform external dimensions throughout their length, the inside diameter being flared outwardly gradually merging from round to hexagonal as at IS, the internal and external hexagonal contours meeting in a sharp edge at the end of the tube as at H and I2 where the inner contour and the outer contour substantially coincide.

Fig. 2 shows the end view of asection of a radiator incorporating a plurality of these tub'es. After assembling the tubes together as shown in this figure, they are soldered at the ends in the same manner as conventional radiator core tubes; i. e., by dipping in molten solder while held in a clamp.

In Fig. 3 the cross-sectional elevation through a. row of tubes taken on the line 3-3 of Fig. 2, the section formed by the contours 8 and 9 represent: ing the lower and upper wetted air surfaces of the walls of two adjacent core tubes, such as land Ill, respectively, on said plane, will conform to the shape of a true symmetrical airfoil having extremities both front and back terminating in sharp edges as at H and [5. The thickest section of the airfoil is on line l3. The cooling air proceeds through the center of the tubes as shown by the arrows 3 and 4, while the fluid to be cooled is circulated around the core tubes in the spaces 5 between adjacent tubes. The line 6-1 represents the chord of the airfoil section which is described as being the lower and upper wetted air surfaces of the walls of core tubes I and I0, re-

spectively. If the upper contour 8 of the airfoil having the line -1 as its chord is rotated about the axis :r-v, which is substantially parallel to the chord but displaced therefrom on the convex side of the contour 8, the surface thus generated will have the form of a Venturi-shaped tube which constitutes the wall of radiator core tube I in Fig. 3. If the lower contour 9 of the airfoil having the same line 8-4 as its chord is rotated about the axis z'-y', the surface thus generated will constitute the wall or core tube in. The wetted" air contours 8 and 9 representing the lower and upper sections of core tubes l and I0, respectively, are symmetrical about their common chord 6-1. Consequently, the air which passes through the two tubes I and I 0 flows around a true symmetrical airfoil and the wind resistance of the two tubes is equivalent to that of a true symmetrical airfoil section.

In the single embodiment of my invention whichI have shown and described, I have suggested the use of round tubing with the ends brought to hexagonal shape, but it will be obvious that the ends could be square or triangular and that the tubing could be hexagonal, square or of other suitable cross section.

Moreover, in the embodiment selected for illustration, I have shown certain curves as at 8 and 9 of Fig. 3 to define the shape of the airfoil, but it will be obvious that the section of the airfoil which will offer minimum resistance in any particular case will depend upon the speed at which the radiator core is to be used.

Having thus described an embodiment of my invention, I claim:

1. A radiator core composed of a plurality of elements, each comprising a Venturi-shaped tube which flares from the throat outwardly toward the ends, mounting portions at the ends of the tubes being externally shaped to uniform prismatic contour throughout their length, theinside contour of the tubes being so shaped and flared that the inside and outside contours come into exact coincidence in a sharp edge at the end of the tube, so that when the tubesare laid with their mounting sleeves upon each other, the section formed by the lower inside contour of the upper tube and the upper inside contour of the lower tube, when viewed at a section formed by a plane passing through the axis of the two tubes, will have the form of a true airfoil section with symmetrical upper and lower contours meeting their common chord at the ends of the tubes.

2. A radiator core composed of a plurality of elements, each comprising a Venturi-shaped tube which flares from the throat outwardly toward the ends, mounting portions at the ends of the tubes being externally shaped to uniform prismatic contour throughout their length, the inside contour of the tubes being so shaped and flared that the inside and outside contours come into exact coincidence in a sharp edge at the end of the tube, so that when the mounting sleeves are held together at both ends oi the tubes, the cooling air which flows through the core tubes will flow around symmetrical airfoil sections which have their upper and lower contours meeting their common chords at the ends of the tubes.

HAROLD W. CASE.

REFERENCES CITED The following references are of record in the file of this patent:.

UNITED STATES PATENTS I Number Name Date 1,713,020 Browne May 14, 1929 1,995,768 Fesenmaier Mar. 26, 1935 2,325,036 Case July 27, 1943 FOREIGN PATENTS Number Country Date 28,811 Great Britain Dec. 30, 1902 27,657 Great Britain Nov. 28, 1910 346,172 France Sept. 12, 1904 168,191 Germany May 29, 1903

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