Bluff-shaped annular configuration for supersonic decelerator for reentry vehicle

Connors, J. F.

English

NASA Technical Reports Server

UNITED STATES PATENT OFFICE 
CERTIFICATE O F  CORRECTION 
P.a ten& N O ,  3,098,630 J u l y  2 3 ,  1563 
J a m e s  F. C o n n o r s  
It i s  hereby ce r t i f i ed  tha t  e r ror  appears i n  the above numbered pat- 
ent requiring c o r ~ e c t i o n  and tha t  the said Letters Patent should read a s  
corrected below. 
Column 1 ,  l i n e  2 1 ,  f o r  ' 5 n c l u d e s "  r e a d  -- i n c l u d e  --;  
l i n e  2 7 ,  f o r  " b u f f "  r e a d  -- b l u f f  --; l i n e  5 4 ,  f o r  " 'Another"  
r e a d  -- A  f u r t h e r  --; column 2 ,  l i n e  16, f o r  " p l a t e "  r e a d  
-- p l a t e s  --; l i n e  3 4 ,  f o r  " t h e " ,  s e c o n d  o c c u r r e n c e ,  ~ e a d  
-- a  - - ;  co lumn 3 ,  l i n e  4 2 ,  i n s e r t  t h e  f o l l o w i n g  a s  a  new 
p a r a g r a p h :  
O b v i o u s l y ,  many m o d i f i c a t i o n s  and  v a r i a t i o n s  
of t h e  p r e s e n t  i n v e n t i o n  a r e  p o s s i b l e  i n  t h e  
l i g h t  o f  t h e  a b o v e  t e a c h i n g s .  I t  i s ,  t h e r e f o r e ,  
t o  b e  u n d e r s t o o d  t h a t  w i t h i n  t h e  s c o p e  of t h e  
a p p e n d e d  c l a i m s  t h e  i n v e n t i o n  may b g  p r a c t i c e d  
o t h e r  khan a s  s p e c i f i c a l l y  d e s c r i b e d .  
co lumn 4 ,  l i n e  4 9 ,  f o r  " b u f f - s h a p e d "  r e a d  b ~ l u f f  - s h a p e d  --, 
S i g n e d  and s e a l e d  t h i s  1 1 t h  d a y  of  F e b r u a r y  1 9 6 4 .  
(SEAL) 
A t t e s t :  
ERNEST W.  SWIDER 
A t t e s t i n g  O f f i c e r  
EDWIN L. REYNOLDS 
A c t i n g  C o m m i s s i o n e r  of  P a t e n t s  
https://ntrs.nasa.gov/search.jsp?R=19700028623 2020-03-17T02:14:11+00:00Z
July 23, 1963 J. F. CONNORS 3,098,630 
ANNULAR SUPERSONIC DECELERATOR OR DROGUE 
Filed Dec. 20, 1960 2 Sheets-Sheet p 
INVENTOR 
JAMES F. CONNORS 
July 23, 1963 J. F. CONNORS 3,098,630 
ANNULAR SUPERSONIC DECELERATOR OR DROGUE 
Filed Dec. 20, 1960 2 Sheets-Sheet 2 
\ 
FIG.4 ( a )  
F I G .  5 
INVENTOR 
JAMES F. CONNORS 
ATTORNEY 
3,098,630 United States Patent Ofice July 23, 1963 
a 2 
3,098,630 FIG. 4 ( a )  is a schematic view of a payload with the 
A m L A B  SUPERSOWHC DECEILEMTOR annular decelmator adjacent to the payload prior to be- 
OW DROGUE ing released. 
James F. Glonnaors, North Olmsted, OBnho, assignor to the FIG. 4 ( b )  is the decelerator in a deployed position in 
United States of America as  represented by the 5 pelation to the payload. 
Administrator of the National Aeronautics and Space FIG. 5 shows a train o r  series of the annulas supersonic 
Adna~iniskaGoln decelerators deployed in relation to a payload. Filed Dec. 20, 1960, Ser. No. 77,252 
9 Claims. (@I. 244-113) Referring now to the drawings, wherein like reference 
(Granted under Title 35, U.S. Code (1952), sec. 266) characters designate like or corresponding parts throuzh- 
10 out the several views, there is shown in FIGS. 1 and 2 an 
The invention described herein may be manufactured annular supersonic decelerator 11 which is similar to an 
and used by or  for the Government of the United States umbrella-like structure having an aperture o r  open area 
of America for governmental purposes without the pay- therein. A plurality of compression rib members 12 are 
ment of any royalties thereon or therefor. pivotally connected to a center shaft 19 at a pivot point 
This invention pertains to a novel annular supersonic 15 29. The rib members 12 are additionally pivotally oon- 
decelerator. Today's high~specd aircraft and missiles nected to a plurality of plate 14 at a pivot point 318 or in 
demand the use of reliable and efficient supersonic re- some applications may be rigidly attached at point 18. 
covery and escape systems. Of prime importance is the l e  plates 14 serve to support the foldable cloth or 
safe reoovery of man-carrying vehicles and capsules a t  metallic fabric 13 which serves as the main resistance or 
all supersonic speeds. Other applications for stabilization 20 the drag-producing area. As can be see the fabric 13 
and deceleration devices would includes the return of forms a pattern oorresponding to the inclined surface of 
instrumented capsules throughout the entire reentry phase a hollow fmsto-cone. The inner circumference of the 
and the recovery of large expensive first-stage rocket fabric forms the boundary of an open area which is 
boosters. The two main criteria used to evaluate the substantially larger than the area of the shaft 99. As the 
aerodynamic perfornzance of such devices are stability 25 annular decelerator moves from a closed to the open 
and drag. In most instances, the bodies to be recovered position shown in FIGS. 1 and 2, a slidable sleeve 97 
are of buff high-drag shapes, which by themselves achieve moves along the shaft 99 causing strut memb~e~s 15 to 
high deceleration rates. The problem is to produce a react against the ribs 12, forcing the ribs to an open posi- 
concentrated drag at some particdlar point in the body tion. The strut members 15 are pivotally connected to 
to keep it from tumblinz and to maintain some predeter- 30 both the sleeve member 97 and ribs 12. A shock ab- 
mined attitude or orientation of the body during free sorber 16 is provided on the shaft 19 downstream from 
fall. In these cases the steadiness or stability of the aP- the sleeve member so as to  cushion the reaction force of 
plied drag force is most important. Obviously, this is of the sleeve 97 when the decelerator is actuated. A towline 
particular importancc with manned payloads. 22 connects the decelerator to the payload and can be 
For Mzch nlmbers less lhcn about 1.5 flexible ribbon- 35 rigidly attached to shaft 19 by conventional means such 
type parachutes appear capable of providing adequate as welding. 
stabilization and deceleration and may be superior to Referring now to FIG. 3 ( a ) ,  there is shown the pay- 
the inflatable balloon decelerator on the basis of Stowage, load 23 and the annular decelerator 11 attached thereto 
weight, and case of deployment. However, for Mach by the towline 22. In  this view the decelerator is in 
numbers greater than about 1.5, both conventional 40 the initial stage of being deployed prior to the towline 
parachutes and the inflatable bluff-shaped balloons en- becoming taut and opening the device. m e  shock wave 
counter increasingly severe shock-boundary-layer inter- 24 in front of the payload 23 is additionally shown. En 
actions resulting in large drag reductions due to conical FIG. 3 ( b ) ,  a decelerator is shown in its completely de- 
fiow separation along the towlines. The flexibility and ployed position. In this view the wake 25 resulting from 
nlultiplicity of towlines around the Outer periphery of 43 the payload 23 is shown as well as the shock wave 26 
conventional parachutes additionally make them rather produoed by drag effect of the decelerator 11. As can be 
unpredictable an'd susceptible to violent instabilities and seen, this scheme uliiizing the annular drag-producing 
gyrations. area keeps the shock wave 26 out away from the central 
An object of this invention is to provide a highly ef- towline 22 and its boundary layer. In this way full nor- 
ficient supersonic decelerator. 50 mal-shock pressure rise is achieved and the drag per unit 
Another object of this ivnention is to provide a super- fabric area is maximized. Thus, by eliminating the inter- 
sonic decelerator which avoids shock-boundary-layer in- action of the decelerator shock wave with towline bound- 
teraction. ary layer and the wake of the paylozd and its attendant 
Another objccl of this invention is to provide a super- separation and drag-reducing consequences, this annular 
sonic decelerator which has no flow separation at high 55 decelerator is superior to the parachutes and balloons. 
supersonic speeds. As seen in FIG. 4 ( a )  the decelerator can be stowed in 
Still another object of the invention is to provide a a flush position indicated by the dotted lines 24 and upon 
supersonic decelerator that has high stability and reliabil- being actuated would open, as showll in the f i ~ r e .  In 
ity. some applications, a solid annular decelerator might be 
Other objects and many attendant advantages of the 60 stowed in the position shown in the figure. 
~~~~h~~ 
present invention will be apparent from the following de- deployment of the decelerator would Shell inv01-i.e separa- 
tained description when taken together with the accom- tion of the annular decelerator froin the and de- panying drawings in which: ployment out downstream to a position shown in FIG. 
FIG' is a pictorial view G5 4 ( h )  to achieve the boundary-layer controf. 
of the annular supersonic decelerator. 
FIG. is a side view of the annular supersonic decelera- is to be noted that the decelerator is shown in FIG. 4  ( b )  
tor shown in FIG. 1. to be within the wake 25 of the payload 22 whereas in 
FIG. 3 ( a )  is a view of the annular supersonic FIG. ( b )  the decelerator was shown in a deployed ~ o s i -  
decelerator shown in relation to a representative pay- tion further downstream from the wake. Thus, it shouid 
load in the initial deployment stage. 70 be ascertained that the decelerator may be used at various 
FIG. 3 ( b )  is the supersonic annular decelerator in an lengths from the payload. 
extended deployment in relation to the paybad. FIG. 5 shows another embodiment wherein a train or 
3,098,650 
3 4 
series of annuli could be stowed concentrically and de- the incline surface of a frusto-cone, the smaller diameter 
ployed in a series, as shown therein. The actual umbrella of said material being substantially larger than the diam- 
mechanisms are not shown in FIGS. 4 ( a ) ,  4 ( b ) ,  and 5 eter of said shaft, providing thereby an open area when 
since these are merely schematic views and serve to show said ribs are in an extended position. 
the relative positioning of the decelerator. 6 4. The combination of a supersonic vehicle, a towline, 
It should be made clear that in any of the annular de- one end of said towline being attached to said vehicle and 
celerators various shapes and construction details can a decelerator attached to the opposite end of said towline, 
be employed. A frustoconical decelerator element is said decelerator comprising, a center shaft having a front 
illustrated herein because it is basically stable. However, end and an aft end and substantially the same diameter as 
in this given concept inflation devices could also be used 10 said towline, the front of said shaft serving as the con- 
to generate the annular shape. necting point to said towline, a plurality of ribs pivotally 
Additionally, it should be pointed out that since the connected to the aft end of said shaft, means for effecting 
basis of the invention is the use of a bluff-shaped annular radial extension of said ribs in a direction away from 
decelerator element, any type of annular element can be the front end of said shaft when said decelerator is de- 
utilized which provides an obstruction to the supersonic 15 ployed, a plurality of plates pivotally connected to the 
air flow. Maximum! bluffness or obstruction occurs by unsecured ends of said ribs, and a foldable material se- 
utilizing an annular plate element which, in its operating cured to said plates, said material having a pattern corre- 
position, is in perpendicular relationship to the air flow. sponding to the incline surface of a frusto-cone, the 
Amount of bluffness or obstruction is decreased by pro- smaller )diameter of said material being substantially larger 
viding an annular doughnut-shaped element and may be 20 than the diameter of said shaft and said towline, forming 
further decreased by providing an annular inclined sur- thereby an open area when said ribs are in an extended 
face such as, for example, the surface of n hollow frusto- position. 
cone. Also, the aforementioned element may be a solid 5 .  A supersonic decelerator, as in claim 3, and includ- 
member rather than the flexible umbrella-type s'hown ing resilient means for cushioning the reaction force of 
herein by way of a specific example. The support mem- 25 said sleeve when said decelerator is deployed. 
bers securing the bluff-shaped ele~ment to the towline or 6.  A supersonic decelerator comprising, a center shaft 
shaft member should be positioned downstream of the having a front end and an aft end, support means piv- 
element so that the shock wave from the bluff-shaped ele- otally connected to the aft end of said shaft, means for 
ment will not hpinge the support members at a point effecting radial extension of said support means in a direc- 
upstream of the element and further the internal open 30 tion away from the front end of said shaft when decel- 
area of the element should be sufliciently larger than the erator is deployed, land means attached to the unsecured 
shaft area so as to prevent impinging of the element shock ends of 'said support means for obstructing supersonic 
wave therein; thus preventing towline boundary layer flow, thereby effecting a shock wave, said obstructing 
separation and the resultant instability and loss of drag means having an inner oplen area substantially larger than 
force effectiveness. It is preferred that the towline be 35 the cross-section area of said shaft 'md said tourline where 
attaohed to the shaft near or downstream of the foremost by the shock wave is prevented from intersecting said shaft 
portion of the decelerator element and further that any and said towline thereby eliminating [boundary layer sep- 
area rise at the point d attachment be maintained at aration. 
a minimum so that the disturbance created by the attach- 7. The combination of a supersonic vehicle, a towline 
men will not e&t the drag of the decelerator. However, 40 attached at one end thereof to said vehicle, and a de- 
the form of attachment of the towline to bhe decelerator celerator, said decelerator comprising a bluff-shaped an- 
is unimportant. nular element, support means for supporting said ele- 
What is claimed: ment, said support means being positioned downstream of 
1. A supersonic decelerator comprising in combination: said element, and means for interconnecting said support 
a center shaft; sleeve means concentrically slidaible on 45 means and d d  towline, said element having an inner 
said s'haft; a plurality of support means pivotally con- diameter fmming the outer boundary of an aperture, the 
nected at one end to said shaft; a plurality of struts inter- area of wwhh is substantially larger than the interconnect- 
connecting said sleeve means and said support mbans; and ing m m  cross-@ctim area. 
means to provide a bluff-shaped annulus configuration, 8. The commbinati~n of chaim 7 wherein the buff-shaped 
said configuration means being supported by said support a d a r  elment is a holiow &usto-cone. 
means, the inner diameter of said configuration means 9. The combination of a supersonic vehicle, a towline 
forming the boundary of an open area which is substan- attached at one end thereof to said vehicle, and at least 
tially larger than the diameter of said shaft when said one decelerator, said decelerator comprising means for 
support means are in an extended position. obstructing a supersonic fluid stream, thereby effecting a 
2.  A supersonic decelerator comprising means for ob- 56 shock wave, said obstruction means having an open area, t 
structing a supersonic fluid stream, thereby effecting a means for supporting said obstruction means, said s u p  3 
shock wave, said obstruction means having an open area, port means being disposed downstream of said obstruction 
means for supporting said obstruction means, said sup-' means, ,and means for interconnecting said support means 
port means being disposed downstream of said obstruc- to said towline, said interconnecting means having a 
tion means, and means for interconnecting said support 60 cross-section area substantially smaller than said obstruc- 
means to a supersonic vehicle, said interconnecting means tion means open area. 
having a cross-section area substantially smaller than the 
open area associated with said obstruction means, thereby References Cited in the file of this patent 
preventing intersection of the shock wave with said inter- 
connecting means whereby interconnecting means bound- 65 UNITED STATES PATENTS 
ary layer separation is eliminated. 2,382,442 Rich et al. -------,------ Aug. 14, 1945 
3. A supersonic decelerator comprising a center shaft, 2,678,785 Gfiaham --------------- May 18, 1954 
a sleeve concentrically slidable on said shaft, a plurality 2,761,636 Finlay ------------------ Sept. 4, 1956 
of ribs pivotally connected at one end thereof to an end 2,946,543 Gordon et al. ----------- July 26, 1960 
of said shaft, a plurality of strut members pivotally inter- 70 2,960,291 Patterson -------------- Nov. 15, 1960 
connecting said ribs and said sleeve, a plurality of plates, 
said plates being pivotally connected to the unsecured OTHER REFERENCES 
ends of said ribs, and a foldable material secured to said Aviation Week, June 22, 1959, pp. 81-82. 
plates, said material having a pattern corresponding to Western Aviation, November 1959, pp. 6-7. 


Annular supersonic decelerator or drogue Patent

Abstract

Similar works

Full text

Available Versions

NASA Technical Reports Server