Niemi, Richard O

English

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h --
,--
) MR No. E6B12
,,
.
NATIONAL
. . .
ADVISORY COMMITTEE FOR AERONAUTICS k+”
WAIM’IME IW!B(BRT
ORIGINALLY ISSUED
February 1946 as
Memorandum Report E 6B12
THE EFFECT OF ETHYLENE DIBROMIDE ON THE
KNOCK-LIMITED PERFORMANCE OF LEADED AND
NONLEADED S REFERENCE FUEL
\ By George R. Kinney and Richard O. Niemi
Aircraft Engine Research Laboratoq
Cleveland, Ohio
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WASHINGTON .-m,..%. .... ---- :’
I NACA WARTIME REPORTS are reprints of papers originally i;~~ed’;o’”’provide rapid distribution of
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E -183
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31176013636409
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—.
LABORATCMY
~j.r Technlcd. Service (hnmnd, Arq ~r
THE EEEFIOT03’ ETHYJiWO DIDEOM~IU OH
ZNOOK-LIMITED PERF3RKWCU! 03’LEADED
S’orcea
Am .
lmmiFfAlmsmmzEwEm
~ Georgo R. Kinnq and Richard O. IWcmi
INJ!2GDUCT10N
Previous investige.tionscf lead fouling havo indicated thct
some c.dv.mtngesmy result if tho concent.r::tionof ethylene dibrc-
mide in aviation fuel is increased abovo the 1-T concentration
Currently used. (1-T or 1 theory of ethylene dibromide is tho
chenico~ly correct emount required to ccanhinewith tho totrnothyl
le~d in r.fuel to convert all tho load to lead bro~ide.) Tho use
of fuel with the ethylene-dibromide content increased from 1 theory
to 1.5 theories h-s resulted in decroc.sodland fouling of the epnrk
plugs in r.lrcr.aftengines. !&o results of tests reported in rofe~
once 1 show thnt, when etl@ene dlbromido in oxcoss of the amount
thooreticclly required to combine with the lend in the fuel was added,
hot corrosion of the exhaust-valve crown ad materieJ deposits on
the piston and tho spark plugs were reduced.
Tests with m air-cooled, cin@e-cyllnder” engino (reference 1)
showed no reduction In the Ynockllmlted powor of an A&W2g,
Anondnent-2, fuel when the ethylene-dibromideconcentration was
Inorensed from 1 theory to 2 theorieo; hcwcver, during tests per-
formed at the I?ACACleveland laboratory on lead fouling of spnrk
plugs, the lmocklimitod power of m 0172engine decreneed when
ethylene dlbromide was added ta ncnleaded S referonco fuel.
These observations suggested the possibili~ that the effect
of ethylene dibromide on the knoclwlimited power of an engine might
depend upon the concentration of totraethyl lead in the fuel. Teets
—
2were therefore conducted”on a CBTl(~-4) en81ne to detemlne the
effect of ethylene dibrcmide on the lmock-llmlted perfoxmanoe of
S referenoe fuel, both nouleaded and leaded to 6 ml !EELper gallon.
The teats reported herein were made at the NACA Clevelemd labora-
tory a~i~ Ootober 1944 as part of an Investigation of md foul-
ing of spark plugs requested by the Air Teohnlcal Servloe @smand,
Army Alr Forces.
APE! AND ZESTS
The bock tests were conducted wltb a
The modlficat ions Involved only details of
lliary Systcmls.
modified F-4 engine.
some of the engine aux-
Air consumption was measured by a calibrated orifice, fuel
consumption was detezmlned by an autmat ic ttie-weight method, and
temperatures were m-sud by chromel-alumel thermocouples. An
alternating-current, InductIon-type dynamometer was used to measure
torque. Knook was detected by a magnetostriction+pe pickup unit
(attached to the cylinder) in combination with an ampllfier and a
oathode-ray oscilloscope. The hock Intensity selected to establish
the knock limits of the fuels was the Intensity that oaueed the
first perceptible Indloatlon on the oscilloscope; this Intensity
was below that for audible hock.
The knock tests were performed with the followlng F-4 operatIng
conditions maintained:
Engine speed, rpu. . . . . . . . . . . . . . . . . . . .. 1900*45
Ofnnpressionratio. . . . . . . . . . . . . . . . . . . . . . .7.0
Spark ad.vance,degrges B.T.C. . . . . . . . . . . . . . . . 45*1
Spark-plug gap, inohes . . . . . . . . . . . . . . . 0.015 to 0.025
Coolant temperature, OF.... . . . . . . . . . . . . ...375 *5
Inlet-alr tmperature, ?F. . . . . . . . . . . . . . . ...225 *5
Lubricating-oil temperature, OF. . . . . . . . . . . . . . . 165 *5
The humidity of the inlet air was not in exoess of 70 grains of
water per pound of dry air.
Khock-limited indicated mean effective pressure nas determined
over a range of fuel-air
6 ml TEL per gallon with
di.bromidein milliliters
and 5.34 (2-T). Similar
containing no tetnethyl
trations of O, 2.67, and
ratios for S reference fuel containing
the following ooncentratione of ethylene
per gallon: O, 2.67 (l-T), 4.01 (1.5-T),
tests were also run using S reference fuel
lead and with ethylene-dlbraide concen-
5.34 milliliters per gallau. Ccqarisons of
HA(2AMR NO. E8B12
knock-limited perfoman Oe were made
sum day. Correspaadingbracketing
3
only among fuels tested cm the
Btandard
. . . . . ... were.mm for the bock-test. d@.a @_&@@ !??I.
RESULTS AND DISCLESICX4
Bhock-limlted performance data obtained
referenoe-fuel ourves
qg*..lay.
oonditlona for leaded @ nonleaded S reference fuel containing
different ooncent=t Ions of ethylene dibrmide me presented in
figures 1, 2, and 3 and table I ewmmarizea the hook-limited per-
famance data ~esmted in these f igurea. The table gives, at
seveml fuel-air ratloe, the relative knock-limited powers of the
leaded fuel with the different amounta of ethylene dlbrcsnidewith
respect to the knock-limited power of the leaded fuel containing
1 theory of ethylene dlbrcmldo. !l!hotable also gives the relative
lmook-limlted powers of thu nonleaded fuel with tlw different
amounts of ethylene dibrccrld.ewith respect to the knook-limited
power of the ncnleaded fuel containing no ethylene dlbranide.
Figure l(m) shows that no appruolable difference in the knock-
llmltod power of S reference fusl containing 6 ml TEL per gallon
wns found when the ethylen+dibrcmnldecontent was decreased fra
1 theory to O theory; nor was thvre any appreciable difference
(see fig. l(b)) when the ethylene-dlbromide contant was Increaeed
frcm 1 theory to 1.5 theories. A deer-ee In knock-limited puwer,
shown In figure l(c), of approximately 8 ~rcent at lean fuel-air
mixtures and 6 percent at rich fuel-air mixtures occurred, however,
when the ethylene dibromide was Increased frm 1 theory to
2 theories.
The knook-llmited performance data showing the effect of
additions of 2.67 and 5.34 milliliters of ethylene dibrmide per
gallon (amounts equivalent to 1 and 2 theories, respectively, for
a tetraethyl lead oontent of 6 ml/gal) to the nonleaded fuel me
presented in figure 2. The knock-limited performance of nanleaded
S reference fuel was reduced by the additions of ethylene dibromide
except at very lean and very rich fuel-air mixtures where little
change wns detected. The reduction In the lmock-limited petiormanoe
of the fuel was greater with the larger addition of ethylene dibro-
mide, Changes in the knock-limited power of the nonleaded fuel for
differences of 2.67 milliliters psr gallon in ethylene-dibrmide
content were relatively small but were reproducible.
Figure 3 presents knock-limited performancee data obtained in
cheek tests; the data check the results shown in figures 1 and 2.
. .
4 HAC4 m No. E6B12
An Inomase In the ethylene-dlbramlde oontent fran O to
5.34 milliliters per gallon deoreaaed the Imock-llmlted power of
both the leaded and the nomleaded fuel approximately the same
amount (6 to 9 perosmt depending upon the fuel-air ratio) except
at very lean and very rich fuel-air mixtures where little ohange
in the Icnock-llmitedpower of the nonleaded fuel was detected. An
Increase In the ethylene-dibrcmlde content frcunO to 2.67 mini-
llters per gallan deoraaaed the knock-limited power of the non-
leaded fwl as high as 6 peroent depending upon the fuel-air ratio
(excupt at very lean end very rloh fuel-air mixtures where little
ohange In knock-limited -r was detected) but had no appreclablo
effect on the kncck-llmlted power of the leaded fuel. An Increase
from O to 4.01 mllllllters per gallon of ethylene dibrcmide also
hadno appreciable effeot on the knock--llmltedpower of the leaded
fuel.
SUMMARY CD’RESULTS
The results of tests made with amodlfled F-4 engine using F-4
operating conditions to determine the effeot of gthylene dibrcmdde
on the knock-limited performance of leaded and nonleaded S refer-
ence fuel m?e summarized below. The tests were made with slight
deviations from the strict F-4 Instrumentation and bock-rating
procedure. The knock Intensity seleoted to establish the tick
limits of the fuels was detem~ned by.an oscilloscope method and
was below that for audible hock.
1. An Inorease In the ethylsne-dibromide content from O to
5.34 milliliters per gallon (O-T to 2-T for 6 ml TEL/gal) decreased
the Imock-llmited power of S reference fuel, both nonleaded and
leaded to 6 ml TEL per gallon, approximately the same amount (6 to
9 percmnt depending upm the fuel-air ratio) except at very lean
and very rich fuel-air mixtures where little ohange in the knook-
llmlted power of the nonleaded fuel was deteoted.
2. An Inorease In the ethylene-dlbranidocontent from O to
2.67 milliliters per gallan (O-T to 1-T for 6 ml T!EL/gal)decreased
the bock-limited power of the nonleaded S reference fuel as muoh
as 6 permnt depsnd~ upon the fuel-air ratio (except at very
lean and very rich fuel-alr mixtures where little ohange In the
Isnock-llmltedpower was detected) but had no appreciable effect
on the lmock-llmited power of S reference fuel leaded to 6 ml TEL
per gallon.
NACA n Ho. E6B12 5
3. An Increaae from O to 4.01 milliliters per gallon of
othylono dibromide (O-T to 1.ST for 6 nil. TEL/gal) had no appr~
oiable.offecton -the.Immcklimltod poyer of S reference fuel le?.dod
to 6 rit ~ per ~lon.
Aircraft Xh@ne Eesenrch Labomto~,
Hatioti Advisory Committoe for Aeronaut1ce,
Oleveland, Ohio.
EE?Em90E
1. MulcPky, B. A., and Zlpkin, M. A.: Tho Effects of an Increase
in the Oonoentration of Ethylem Dibromlde in a Leaded B’uel
on Lead Deposition, Corrosion of Exhaust V=ilves,and ILcoc&
Limited Power. NAOA JIRRNo. E5EOb, 1945.
—. .
II’ACLE. N@. WB12
TABLE
IN
~O~-LIMITEO POMERUFACWR ENGINE UNDER
F-4 OIXRATING CONDITIONS
[Where two values are given in the table for the same
determination, the second value was obtained fran a
check run]
r s‘“ere=el
dlbrcmide In Relative powe~
S reference
fuel + 6 ml Fuel-air ratio
(ml gal) 0.062_ 0.070 0.090 0 l110
2.67 (l-T) 1.00 1.00 1.00 1.00
0 (O-T) 0.98 1.00 1.01 1.00
1.01
4.01 (1.5-T) 1.01 1.01 1.01 1.01
.99 1.00 .90 1.00
5.34 (2-T) 0.92 0.91 0.94 0.95
,95 .93
Nonleaded S reference fuel
Ethylene
dibromide In Relative powerb
no.nleadedS
referente Fuel-air ratio
(m~,ga~) ~G o o~o 0,,0 o,,;
fuel
? . . l
o 1.00 1.00 1.00 1.00
2.67 0.98 0.96 0.94 0.97
.96 .98
15.34
~
‘ 0.97
I
0.92
t
0.92 0.97
.94 .96
aimep (S + 6 ml TEL + teet concentration of ethylene dlbrcmide).
I.mep(S + 6 ml TEL + 2.67 ml ethylene dlbromide (l-T))
blmep (S + test concentration of ethylene dibrmide).
Imep (S)
National Advi80ry Ccunmittee
fOr AWOLLSUtiCB
NACA MR tiO. E6B12
P
NATIONAL ADVISOUY
COMMITTEE FOR AERONAUTICS
j
[
.,. .,
70
3
~ ~- -
---
60
6
7“ - -
-i- - -
-- --0
- --
--
+
4
~
~. ..0-- ‘-
so :
~--- ‘-o
TEL Ethylene-
40 content dibromlde(mi/gal ) concentration
6 0 mll al (O-T)
--- . P2.67 ml gal (l-T) (reference blend)
--;- - : 1-T (reference blend)
30 ]
260
.-+- - -. ~ -- --
/ r .-240
[
--
---
‘ -.
v
220 ~. “
/
am
/
/ /
,~ y //
180
140
140
.06 .06 .07 .m .09 .10 .11 .12 .13 .14
Fuel-air ratio
(a) Ethylene-dibromide concentrations, O and I theories.
Figure 1. - Effect of ethylene dibromide in S reference fuel leaded to 6 ml TEL per gallon on
knock-limited performance of a CFR engine. Engine speed, 1800 rpm; compression ratio, I’.o;
spark advance, 45° B.T.C.; coolant temperature, 375° F; inlet-air temperature, 225° F.
NACA MR tiOo E6B12
NATIONAL ADVISORY
COMMITTEE FOR AERONAUTICS lr’’~’l’’’’ol’’’l’’ol’’’’l’’’’l’”~
60
so
260 -
.- --
.
5
./-’
220 ,#--
[
/“
3xx
200 .
160
140 , , , , I , *,, ,, 1 ,, ,1 I ,11..
.05~ .06 .07 9.09 .10 11 X* ,- .
Ilj,,.,,,,,,
- -- . A“
. *- .14
Fuel-air ratio
(b) Ethyl ene-di.bromide concentrations, I and 1.5 theories.
Figure 1.
- Continued. Effect of ethylene dibromide in S reference fuel leaded tO 6 d TEL per
gallon on knock-limited performance of a CFR engine. Engine speed, 1800 rpm; compression ratio,
7.0; spark advance, 45° B.T.C.; coolant temperature, 375° F: inlet-air temperature, 225° F.
~-—. .— --
NACA MR No. E6B12
,..
c
*
e
E
NATIONAL ADVISORY
COWITTEE FOR AERONAUTICS
70
E I I I I I I I l-..-t+--t+-~ s ~ i
50 -. ~--. +-- . I I I I I I I
E b I Tim Fithylene-TV
40 . /1 I II l“Q I I content dlbromlde(ml/gal) concentrateion I
-- +-- 6 2.67 ml/gal (l-T) (reference blend)
6 5.34 ml/gal (2-T)
r --o-- l 1-T (reference blend) IL
so :
\
260t
c .-+-,--- -+-,------
240 <“
+. H
.
.-
]
+ ~ - v
/ ~-.
+. “
~--
- .-
+ .~- +
‘0
220
.’”
.
.
,*’ .
200 - / ),/ /
/ ?
/
/ /
1
14
.0s .06 .U7 .00 .06 .10 .11 .12 .13 .14
Fuel-alr ratio
(c) Ethylene-dibromide concentrations, I and 2 theories.
Figure 1.
- Concluded. Effect of ethylene dibromide in S reference fuel leaded to 6 ql TEL per
gallon on knock-limited performance of a CFR engine. Engine speed, 1800 rpm; compression ratio,
7.0; spark advance, 45° B.T.C.; coolant temperature, 375° F; inlet-air temperature, 225° F.
.NACA MR No. E6B12
.. . . .. . -,
NATIONAL ADVISORY
so
40 -
% ~
v
: v>. .
E thyIene-
,--~ ~
content dlbromlde
20 : (ml/gal) concentration
--4-- 0.5 1-T (reference blend)
--o -- 0 0 ml/gal (raference fuel)
4— o 2.67 ml/gal
L 5.34 ml/gal
~ ‘M:%=%%+]
--v--
(reference blend)
1s0
.A- ---- --’u----- ---
160 -
.
/“
/“
140
.-
,4‘
/
,0
4
/
120 /Y /8 // , ,ti*- / /
P
/
,/
.
> ‘-
4’
v .’
~ ‘\
80 .’ --- -- -.--O
c
an ,-- ——
.06 .06 .07 .02 .09 .10 .11 .12 .1s .14
Fuel-”airratio
Figure 2. - Effect of ethylene dibromide in nonleaded S referenoe fuel on knook-limited per-.
formance of a CFR engine. Engine speed, 1800 rpm; compression ratio, 7.0; spark advance,
450 BOT.C.; coolant temperature, 375° F; inlet-air temperature, 225° F.
NACA MR No. E6B12
c
g
e
“-NATIONAL ADVISORY
50 -
E
.Jl- ---- --e -
40
--- -a-- *
~. -- -J
[ -- .
--
Ja ~#- 4
% ~ “6
* --- -7 - v
.- -
“\
30 - —* 4
~-- j
N-“ v
TEL
:v-. . .
Ethylene-
content dlbromlde
20 - - -–
-. (ml/gal) concentration
---4-- 0.5 1-T (reference blend)
--cl-- 0 0 ml/gal (rs”ference fuel)
4— o 2.67 ml/gal
o 5.34 ml/gal
–-v--
[
“90$ S reference fuel +
10% M reference fuel 1
(reference blend)
180 -
160
120 -
.
p “ /
4’
“.—.
.05 .06 .07 .02 .09 .10 .11 .12 .N .14
Fuel-’air ratio
Figure 2. - Effect of ethylene dibromide in nonleaded S reference fuel on knock-limited per-,
formance of a CFR engine. Engine speed, 1800 rpm; compression ratio, 7.0; spark advance,
460 E.T.c.; coolant temperature, 375° F; inlet–air temperature, 226° F.
MACA MR HO. E6B12
.
260
240
220
2CQ
c
:
E
leo
NATIONAL ADVIS’ORY
r
COMMITTEE FOR AERONAUTICS
24o
Ethylene-
220 content Dlbromlde
(ml/gal ) concentration
(ml/gal)
-—+–- 6 2.67 (l-T) (reference blend:
200
(reference fuel)
.180
k-
/“
160
.
.
160
~+/
d
8
140
MO
100
.
.05 .06 .07 .06 .02 .10 .11 .12 .13 .14
Fuel-air ratio
Figure 3. - Check curves for data presented in figures 1 end 2.
1-
1
Illllliilllnlll!nu
3 1176013638409 _


The effect of ethylene dibromide on the knock-limited performance of leaded and nonleaded S reference fuel

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