Injector manifold assembly for bipropellant rocket engines providing for fuel propellant to serve as coolan

Heidmann, M. F.

English

NASA Technical Reports Server

March 3, 1964 M. F. HEIDMANN 
INJECTOR FOR BIPROPELLANT ROCKET ENGINES 
Filed June 19, 1961 3 Sheets-Sheet 1 
INVENTOR. 
MARCUS F. HEIDMANN 
ATTORNEY 
https://ntrs.nasa.gov/search.jsp?R=19700029394 2020-03-17T02:14:49+00:00Z
M. F. HElDMANN 
INJECTOR FOR BIPROPELLANT ROCKET ENGINES 
Fi l ed  June 19, 1961 3 Sheets-Sheet 2 
@ HYDROGEN DISTRIBUTION ORIFICE 
LEGEND 0 FUEL INJECTOR ORIFICE 
OXIDANT INJECTOR ORIFICE 
F I G .  2 
18 
- 
F I G .  3 
18 
- 
F I G .  4 
INVENTOR. 
MARCUS F. HElDMANN 
ATTORNEY 
March 3, 1964 M. F. HEIDMANN 3,122,885 
INJECTOR FOR BIPROPELLANT ROCKET ENGINES 
Filed June 19, 1961 3 Sheets-Sheet 3 
FIGURE 5 
MARCUS F. HEIDMANN 
INVENTOR. 
&& 
ATTORNEYS 
3,122,885 Urllited States Patent Oace . ,,,, ,,,. , ,,
3,122,985 
INJECTOR FOR BBBI<OP@LLANT ROCKET 
ENG1NES 
Marcus B. IHeidanaran, Rocky River, Ohio, assignor to the 
Uuitcd Skates oS America as represented by the Ad- 
minis~atur  of the National L~esonautics and Space 
Admiaais&atiorn 
Filcd June 19, 1961, Ser. No. 128,282 
2 Claims. (CB. 60-35.6) 
(Grantcd under Title 35, U.S. C08e (1952), see. 266) 
The invention described herein may be manufactured 
and used by or for the Governrncnt of the Uniied States 
of hmcrica for governmental purposes wib\out the pay- 
ment oT any royalties thereon or therefor. 
P ibis invention relates generally lo a device for inject- 
ing propellants into a rocket thrust chamber and more 
parLici~larly to ail improved fucl and oxidant injector. 
1 he ~sope?lant injector is one of ilze major components, 
and at the came time one of the most vulnerable to mal- 
filnclion, of :he rocket engine, functioning to introduce 
and meter the flow of the propellants to the combustion 
chamber, vihilc at the same time it atomizes the propel- 
lants for ready combustion. It is extremely important that 
these functions be performed so that a correctly propor- 
tioned fu.1-oxidizer mixture atill result which can be 
readi!y vaporized and burned. The particular injector 
pattern efi~ployed, orifice size and arrangement, may of 
co:irse vary. The design criteria is that the injector must 
obtain as uniform and predictabie a mixture and mass dis- 
tribulon across the injector face plate as is possible, and 
that it combine lightweight conshruction with high per- 
iormance, simplicity 2nd re!iabiilty. 
A major failing of the prior art is the liability of the 
injector face plate to ablation and the difEculty of pro- 
viding for uniform cooling of the injector face so that a 
uniform siress distribution is obtained duriilg heatins and 
cooling of the injector. In  addition, the known prior art 
injectors in general fail to obiain a uniform pressure 
drop across the injection orifices of each propellant, which 
 mif form pressure drop is desirable as a characteristic in 
that such uniformity leads to a more predictable mass and 
mixture distribution across the injector face, thus obtein- 
ing uniformity in combustion. Lastly, it is diR~cult in the 
kilo.;gn prior art devices to readily seal joints between the 
oxidizer and fuel passages because of the physical con- 
siruciion and relationships obtairiing in such injectors. 
I t  is a g-neral object of the invention to provide im- 
proved means by which con~bustion liquids may be cle- 
li~icred to :I cornbnstior, chamber. 
It is a f ~ ~ r t h e r  genera1 object of the invention to provide 
an innproved method by which two combuslion liquids 
inay bc dclivcrcd to a combusiion chamber. 
It is a further object of the invention to provide a bi- 
propeilsnt injector assembly capablc of developing a pre- 
cieterni~ed stream patiern. 
It is n more specific object of the invention to provide 
an improved means of delivering combustion liquids to a 
con~bustion chamber so that one of the propellants acts 
as an  internal coolant for a colnponent of the chamber. 
hr is a further, more specific object of the inveniion to 
posiiion the propellant manifolds of a rocket engine so 
that the n~anifolds cornprise a poriion of the walls of the 
rocket motor while the fuel serves to cool the face of the 
injcctor. 
It  is an additicnal specific object of the invention to 
provide an injector assembly wherein a pcrtion of the 
oxidant system serves to reinforce the structural compo- 
nents of the device. 
According to the present invention the foregoing arrd 
other objects are obtained by providing a rocket motor 
with wh3t may best be described as a wafer-Iike iiijector 
assembly. This asserilbly has manifoIds for each of tile 
propellants, which manifolds are "in-line" and form a 
portion of the roclcct motor itself. The fuel manifold 
communicates with a coolant chamber provided betwcen 
6 this manifold and the injcctor face plate so that fuel in 
ptassing froin its manifold to the combustion chamber 
acts on the rear face of the injector face plate to cool the 
facc plate. This construction permits the propellant mani- 
folds to be maintained at near stagnation conditions, since 
10 they do not sene  2s coolant passages, which iil turn per- 
mit? the obtaining of unirornl orifice p:essure drop, meter- 
inr;, 11122s distribztion and controlled mixture distribution 
across the iajcctor fece. The oxidant propcllant is sup- 
plied lo the com5ustlon chamber thrcugh injection tubes 
15 which pass throcgh the fuel manifold and coolant cham- 
ber to the injector face in the combustisn chamber. This 
configuration aids materially in the structural strength of 
the assembly, thus permitting lightweight construction. 
Since tbcsc tubes are straight and relatively short they 
20 provide an ideal cntracce means to the combustion cham- 
ber, permiltin2 a uniform pressure drop and forming a 
jet of known characteristics due to the identical flow en- 
trances to all injection orifices. Hn addition, the joints 
occurring between the oxidizer and fue! passages are readi- 
25 ly sealed since they occur around small, stable tubes rather 
than the longer or linear joints which exist in concentric 
or parallel manifold designs of the prior art. An addi- 
tional feature of the invention is the "checkerboar$" ar- 
rangement of the propellant distribution orifices. This 
30 construction perinits the thrust lcvel to be varied, assum- 
ing other parameters are fixed, merely by encon~passing a 
larger or smaller seement of the repeating arrangement, 
and obtains a maxin~um interspersal of the propellants 
upon injection into the combustion chamber. 
35 Other objects and many attendant advantages of the 
present invention will be apparcnt from the following de- 
tailed descrivion when taken together with the accom- 
panying drawings in which: 
FIGURE 1 is a sectional side elevation of an idealized 
40 thrust chamber assembly, for orientation purposes only, 
and showing the general arrangement of the invention; 
FIGURE 2 is a front view, with the intervening plates 
rcmoved, of the cheokerboard arrangement of the inven- 
tion; 
FIGURE 3 is a sectional view of the wafer-like con- 
struction of FIGURE 2, with the plntcs in position, taken 
011 the lines 111-HII; 
FIGURE 4 is a sectional view at point "A" of FIG- 
URE I: along line PV-IV wit11 the intervening plates 
50 in position, and 
FIGURE 5 is a perspectLve view of the rocket motor 
with portions broken zway. 
Referring to FIGURE 1 for orientation, there is shown 
a rocket motor 11 comprising a combustion chambcr 
55 18 and noz~le  portion 19. A simp!ified injector as- 
sembly embodying the prhciples o i  the invention is 
designated generally by 28. The injector assembly 20 
conprises a c ~ ~ r v e d  injsctor face plate I6 disposed across 
the cross-scciional area of the chamber and having an 
oxidrnt injector orifice 24 ceniraliy formed therein and 
a plurality of fuel injector orifices 22 obliquely formed 
therein about the orifice 24. 
A coolant chamber 14n, which serves to coo! the in- 
jector face plate 16, is formed between a concave fuel 
65 distri'oution plate 15 and the rear face, of the injector 
face plate 16. Chamber Ida is in communication wilh 
the conibustion chamber 18 through the fusl injection 
orifices 22 in the injector face plate 14, and wi!h a fuel 
~nanifold 14 (defined by the distribution plate 15 and 
70 a concave separation plate 13) through the distribution 
orifice 23 in the distribution plate 15. The compara- 
3,120,886 
3 4 
tivcly snla11 vo!i;me of ihc coolant ci:an~bcr E$il in rela- 5. The fli~ori~lc injector tribes 28, besides li:c 1;Gn:ary 
tion to t!le rciativciy large volume oT the Cael manifold fnnciimil OF csrrying the Zitorlne, also h::vc an ii?;por- 
114, as seen in FIGURE I ,  obtains a sirbstantially stag- tanl sccondary Sunc!,ion as sirt~ciural n.:c:nbcl-s whicl~ 
nant condi:ion within the fuel manifold, as explained add sirength to thc wafer construstion, thcr-ly permit- 
in detail hereinafter. and a rclaiively rapid Aow of fuel ting a lighter consiructioil. In adtiillon, such consiruc- 
in and through tbe coolant chamber B4c, thus oplirilizing tin!; provides ideal cnirnnce passage to !he con~b~~st ion 
the operalion o? the coolant c!?amber. chainber 16 through the fl:iorine injaction oi-ilices 24 
An oxidant manicold 22 is delineated by a concave due to ihc possiisiliiy of ob!aining both ui;iierm prcssore 
cover p!atc 17 and the separation plate 15. The mani- and a jet oF Iijlowil charactcri:jlics becr:i!sc of ihe con- 
fold 12 is provided wiih an oxidant injzctor tubc 21 fig:!raliog ani: relaii~nship 01 the tubes to the nanilold 
which passes cen:rally through the fuel manifold S4, and coabus:ion chamber. 
fuel ciistrlbution plate 15, cooling chamber 14n and in- Hydrogen passes in a flow train from the hydrogen 
jector facc plate 16, cncling in ihe oxidant injection cri- nlanifold 14 through the distribution piate I 5  and enters 
ficc 24 at the combus:ion chan~ber. Since the only pos- coolant chambrr 14a (FIGURES 3, 4. and 5) betvieen thc 
slble source of !eakage betwcen the oxidant and fuel distribution plate and face p!ate 16. The bydrcge~l 
manifold is the oxidnnt injcclion P L " ~  21, with 11ie ex- l5 enters the coolant chamber 14n through the hydrogcn 
ception of :he periphery of the separation plate 13, it distribution orifice 33 (as best shown in FIGURES 4 and 
is obvious that the sealing of the two n~anifoids from 5) in the center of a square of fluorine tubes, i.e. the 
each other is readily acconplished by nlereIy insuring hydrogcn distribution point ''L4" of FIGURE 2. This 
the scal aror~nd the oxidant injector tube 21 mbcre it 20 arral~gcment is niost eficient in that it pcrnlii:; each hy- 
passes tiireugll thr separation plate 13, a relatively simple drogen distribution orifrce 23 to pariialiy sapply four 
operation considering the sniai! size and siabiliiy of the adjacent hydrogen injcc'tion oriijces 22 (as iiiiisiratcd 
poriion to be ~caIcc1. Also i; is o b ~ i o ~ s  [Elill tile o:d- by the flow arrows in the upper, right portion of FIG- 
dnni i:~jeaior iiibc 21 siructoraIly reiniorczs 1112 3 s ~ : ~ -  U2E 2) SO that a more riniioi'r;~ prcssiirc and m;:ss c!ir;- 
b!y wl-~ilc pcrmiiiing reaciy ascess of o:.ii?aj-i~ to the Iribution is obtained. The hq.drog.,n injection nri.fices 22 
conibr!stioii chamber 2nd providing a jet of !;ngw:z ciiar- 25 in tile injec!or face piate 16 are !ocated be:w:cn at!j;l- 
acteristics Grie (0 the ilyliforrn pressure ci1.o~ arid i:car cent fluorine tubcs 24 anci fiiicrinc injeclor or-ilices 24 as 
stagnation condiiio~s obtainiiag with the cons!.ror"lion. most c l e ~ l y  shown in FIGURES 2, 3 an<! 5. This per- 
This is due to [he i:lci that the fuel a;-,d oxidant arc mits each oxidant inj2c'rion orifice 23. to 132 impinged by 
under us,iform presscrc wii:lill :heir rcspc;~f\:e ma:?i- a pair of fuel injection orifices 22. Thns, each hydrcjgen 
folds, siilce there is no cooling of engirr2 p;ir!s at the 30 dktribuiion orifice 23 partialiy su~plies forr hj;cirogen 
manifold, and the fuel no: be subject lo Iicaiing, injection orificcs 22, while each of the hydrogcn injec- 
excessive expansion or currcnls and the Lln- tion orifices is symnietrically supplied from two diamet- 
stable reslllis thereof \&ile it is in the ~h~ rical!~ opposed directions. This construction greatly fa cil- 
in turn, has a direct coxmianication lvith the 35 itates providing an cven mixture of propellacts within the 
combustion chamber. combustion chamber and, obviously, a maximum degree 
~i~~ manifolds 12 and 14 s4,plied by ;he lines of uniformity of orifice pressure! drop, metering, mass dis- 
30, 31, respeci;ve~y, disposed throUgb :he cover hy, tribution and mixture dis'iribution. Thus it is apparent 
.from prcpe;12nt reservoirs (ilol shown:. ~ 1 -  that the described construction reinforces the conlposite 
t;loLrgh fuel injection orifices 21 are si,own as being qo struclure whilc nt thc same time it providcs manifo!ding 
formed obliquely for tile p,Jrposp, o~ obiaining a irip!2+nd flow paths which scrve to carry oni the novel method 
impinging it is obvious tllak the pa.+terll of uniformly ccoiing 'the injcctor plate anci prod!icing and 
could be varied to include any of well maintaining the desired pressure and injection character- 
icjectioc types such as doublet impinging, shower head, istics. 
etc., merely by rcorieniing the injection orifices. The design concept is not 1in:itcd to hydroger? ?.nd Aao- 
specific of the invention is illuslrated 45 rine as propeIlants of course, but may be adapted lo any 
in FIGURES 2-5. liquid or gascwlis biprcpeilant combinatioil. The 112echani- 
injector as exemplified by eIilbodiment of ca1 details such as orifice size, spacing, inj,zcior types. etc. 
the invention, and as nlost shovJn in FIGURES are subject to app!ication within wide limits to rn& the 
?, and 5 ,  js a wafer-iike construclion and co:imprises s~eciflc req:riremei>.ts of pro2eilant combinatio~~s. ize, 
a Ruorine manifold l2 formed by a cover (not weight, etc., without departing from the scope of the iil- 
shown, but illustraied by plate 17 in the orientation view ventioa. 
of FIGURE 1) and a separation plaie 23. Immediately It Is therefore seen that an injector assembly has bcen 
adjacent to the Buorine manifold 12 is a hydrogen mani- provided for use in a rocket motor which overcomes the prior art objections and defic3encies by providing such an fold 24, the scparzition piate 13 serviilg as the I o ~ e r  
the ard tile uppar 55 assembly with in-line manifolds, the inanifolds being an es- 
se~ztially integral portion of thc motor, bcing easily and head for the hydrogen manifold. A coolant chamber 
expeditiousIy sealed fro111 one another and being capable 14n, formed by a hydrogen distribution plate 15 and the 
of maintenance at near stagnation conditions. one oC the 
rear face of an injcctor face plate 16, is i:? communi- 
nilznifolds communicating with a combustion chamber 
cation wit11 the hydrogen manifold 84 by menns of i.1.y- 60 through an interrnediatc chamber which serves to cool 
drogeil distribution crifices 23 (see FIGURES 2,  4. the injector face, tile other manifold communicating \vi:h 
and 5).  the combustion chamber by means of sbost. stable "lube:; 
The fluorine enters the coitibusiion chamber IS  (FIG- opening directly into the con~bustion chainbcr. a!? oE the 
U E S  3 and 5 )  through fluorine injcctor tubes 21, which injection orifccs bearing a relatioilship o;lz 
tubes end ill injection orifices 24. Thcsc injector lubes 65 io another to derive eficient mixrure and disiri- 
21 are iil conimunication with the fluorine manifold 12 bution of proprllants. wafer design is strollG, 
and pass thrcug!~ the separation plate 13, hydroaen maci- light, and el'iicient as herein employed. The injector face 
fold 24, hydrogen distri%uticn plate 15, codant cham- itself, because of the cooling by one of thc propellants be1 140, and the injccior face plate 16. It should bc and thp dislribueion and of the proFlcB- 
noted that the rear face of the irijectw face pjate 15 70 lants is subject to fracture by stresses praduccd by 
is formed with bosses 25 which scrve to space the dis- pressure or nonrlniform heating, thus eliminating, substan- 
tribulion plate 15, sca!.ed thereon, from the injector faca tially, critical seals in the illjcction face plate. 
@ate, thus forming the coolant chamber 140. The ritla- The sfructure is easily adaptable to var.ioi~s i11,iector 
rlnc iiljector tubes 21 are nlost convecien:!y positioned patterns by merely reorienting the orifices but  without 
through ihesc bosses, as best silow11 in FIGURES 3 and 75 nlzjor strilctural change, and the lhru:it icvcls m i -  



Injector for bipropellant rocket engines Patent

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