MR No. E5F30

NATIONAL

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ADVISORY COMMITIEE FOR AERONAUTICS - _

WAIU’IME IuwolrrORIGINALLY ISSUED

June 1945 asMemorandum Report E5F30

EFFECT OF INTERNAL COOLANTS ON THE KNOCK-LIMITED

PERFORMANCE OF A LIQUID-COOLED MULTICYLINDER AIRCRAFT

ENGINE WITH A COMPRESSION RATIO OF 6.0

By R. Lee Nelson, Myron L. Harries, and Rinaldo J. Brun

Aircraft Engine Research LaboratoryCleveland, Ohio

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WASHINGTON

NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution ofadvance research results to an authorized group requiring them for the war effort. They were pre-viously held under a security status but are now unclassified. Some of these reports were not tech-nically e+ited. All have been reproduced without change in order to expedite general distribution.

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https://ntrs.nasa.gov/search.jsp?R=19930093190 2020-05-23T08:21:30+00:00Z

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NATIOMAL AImsoRY CxMm!Tm FaR

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for the “

El?TECT03’IRll!RNALCOCLKNTS ON THE KNOCK-L~ PERFORMMCEOF ‘

A.LIQUID-COOLED MULTICYLIKOER AIRCRAIT ENGINE “

WITH A 00M?RESSIOIVRATIO OR’6.0

~ R. Lee Nelson, Myron L. Harriesand Rlnaldo J.

suMimRY

An investigatIon was conducted to determine the effect ofInternal coolants on the knock-limited performance of a llquld-cooled multlcyllnder alrcrsft engine with a displacement of1710 cubic Inches and a compression ratio of 6,0. Rhock-limitedFerforruanceteeta were conducted at an engine speed of 3000 rpm,fuel-air ratios from 0.075 to 0.085, carburetor-air temperaturesof 1200 and 60° F, and with water and water-ethanol as Internalcoolants. Each Internal coolant was Injected In turn through thefuel-spray nozzle and through Intake-manifold spray jets. All testswere conducted with 28-R fuel.

The following results were obtained:

1. The maTtium knock-limited brake hor~power attained was2310 at a fuel-air ratio of 0.CJ79and a carburetor-air temperature ‘of 60° F with 663 pounds ~r hour of water-e~ol Introducedwiththe fui91through the fuel-spray nozzle. ,.

2. In general, at low internal-coolantflows.or a~ the high.. “ccarburetor-air temperature,water was more effective than wat”er-.ethanol In raising the hock-limited brake horsepower, As ttiinternal-coolantfluu wak Increased or.the carburetor-air temper-ature decreased, water-ethanol beqame more effec%ive thqn water... .. ..,

3. Fuel-nozzle”Injection of a given Internal coolmit at agiven carburetor-airtemperature.was general~mo?% effective In ‘“raising the knock-llmited bmake horsepower than ln~ection throughintake-manifoldpmay jets.

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2

4. Except atmanifold pressure

“ti m I& k5F30

sane of the lower Interual-coolant flows a hi@erwas required to obtain a given knock-limi’md brake

horsepower by means of internal-coolant lnJecthn * by means oflowering the carburetor-air temperature.

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At the request of the Air Technical Service Command, Army AirForces, tests are bei~ condn.ctedat the NACA laboratory in Clevelandto evaluate several methods of Increaelng the power output of a liquld-cooled multicylinder alrcreft engine. The effect of water Indectlonthrough 12 spray ~ets in the Intake manifolds on the lmock-limlted -perfo-ce was detezmrhed by tests repcrted in reference 1.

This report presents the results of teets conducted from Julyto Deceniber 1944 to determine the effacts of Iaternal coolants onthe lcnock-lYmitedperformance of test en@ne with a ccmpreesion ratio .of 6.0, The data were obtained from eight series of hock testsusing two internal coolants inJected by each of two methods at carburet~ -atr temperatures of 1200 and 600 F. !Ihpwater and a mixture consisthgof 50 percent water and 50 percent ethanol by volume wsme used asinternal coolants. Each internal cooiant was injected with the fuelthrough the fuel spray nozzle and also through 12 spray Jets mounted inthe intake -olden

APPA2A’IUS

Engine. - The tests were conducted on three V-type 12-cylinderliquid-cooled aircraft engi”nesof 1710..cublc-lnchdisplacement fittedwith pistons giving a compression ratio of 6.0. In order to decreasethe possibilities of pleton failure, the diemetral clearances betweenthe pistons and the cylinder WE&La were increased 0.008 inch over thestandard diametral clearances. lkiclicylinder had two spark plugs, onebetween the two exhaust valves and one between the two intake valves.The engines are equipped with single-speed, single-stage euperchargere

1with impeller diameters of 9- inchee and gear ratios of 9.6:1.

2

winetd.lation. - The engine-dynamomter installation wasthe came as that used for the tests of reference 1.. The externalcoolant was a mixture of 70 percent water and 30 percent ethylenegQcol by volume. The laboratory refrigerated-air system supplieddry caubustion air by first cooling atmospheric air and then heatingIt to the desired temperature. The engine was fitted with special

watem-Jacketed exhaust stacks having inside diameters of 1~ Inchee.16

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EAOA m No. E5E’30 3

This size represents a reduction in diameter of 1/4 inch below thediameter of the exhaust-val.ve-portoutlets and a reduotlon in.area of 27.4 peroent. The exhaust gases were oarrled a- througha 12-inoh-diametergallery within which exhaust-gas cooling wasacomuplished lW multiple sprays of water. Rremnare In”the gallerywhs held slightly below atmospheric by an exhauster fan. . .

Internal-coolant in~ection equipment. - TWO Zntezmal.-ooolant. —.— .— —lnJeothn systems were used. In one system tha Interns} ooolant wasIntroduced oontlnuouslywith the fuel through the fuel X nozzle,whfoh spr~ed the liquid lhto the ,superohergerinducer. Inte~lcoolant was”supplied to the fuel spray nozzle by a line from a tankwhere the Internal coolant was k&pt under pressure by compressed air,bternal-coolant fluw”rates were measured by a oallbrated rotameterin the line from the tank to the fuel nozzle.

In the second system, internal coolant was continuouslyinjected through 12 spray Jets inserted Into the Intake manifoldsthrough holes drilled in the top of the manifolds about 1 inch backfrom the faoes of the manifold mounting flanges. The spray jets were

5/32-inch-diameter stainless-steeltubing about 2* inohes long with

SIX holes, 0.025 Inch In diameter, arranged in two rows of threeholes each to spray Internal coolant directly into each intake port.The spray ~ets and their installationare shown In figures 1 and 2of reference 1. Internal coolant was supplied to the spray Jets byindividual llnes from a tank where it was kept under pressure bycompressed air. Internal-coolantflow rates were measured by cal-ibrated rotameters in the individual lines.

SQecial equlpment and instrumentation. - Vibration-type pickup.—— .—units we=used for knock det=ct=n. Xhock indication was by meansof an amplifier-oscilloscopecombination In whioh a commutator wasused to reduce background Interference.

Fuel-air mixture control”was facilitated by the use of an’ air..bleed valve oonnected across the air diaphragm in the metering sectionof the carburetor.

Carburetor-Inlet statio pressure was measured by a mercurymanunwter connected to a ~atic-@ressure tap. This tap was looated

on the cmibustlon-alr @aok”45m inches upstrbam from the ,oarburetor

face at a point where the cross-seotlonalarea of the stack was.12.5 square Inches. Carburetor ~tic-pressure drop was masurdby a meroury manomet6r connected to the pressure taps on thecarburetor.

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Carburetor-air tempe=lmres were measuredconstantan thermmouples connected in parallelsurvey the air stream immediately ahead of thetempemture data reported herein were obtained

by eight lron-and arranged tocarburetor. Mixture-with an unshielded

the&ooou@e insert~d to the center of the central manifold approx-

imately 9* Inches duunstream from the flange of the supercharger

outlet; therefore, when lnterr~l coolant %=s Injected throtjghsprayjets in the Intanw canifuida, mixture--ce~~p5:*aturemeasurements weremade upstream from the pctmcs of In.p.%ion. Another unshieldedthermocouple inserbed through tlw right rea~-manifold primer holewas used for checking mixture temperatures. Readings from thisthermocouple, whloh are not presented In this report, were approx-imately 10° F higher than those from the oentral-manifold thermo-couple.

TEST CONDITIONS AliDPROCEOURE

The two internal coolants used were tap water and a mixture,by volume, consisting of 50 percent water and 50 percent ethanol(ethyl alcohol denatured wlth5 percent methyl alcohol). Knocktests were conductedat fuel-air ratios from 0.075 to 0.065 with as-eat a r-e of internal-coolant flow as was possible under llmita-~ions Impos=d by auxiliary equipment at each of the followingblnations of conditions:

Series Carburetor-air Internal Means of lnternal-temperature coolant coolant injection

(OF)

1“ 120 Water-ethanol Fuel.nozzle2 60 ---do-------- Do.

com-

3 120 ---do-------- Intake-manifold spray Jets4 60 ---do-------- Do.5 120 Water Fuel nozzle6 60 ---do---- --- Do.7 120 ---do-------- Intake-manifold spray Jets8 60 ---do-------- Do.

For the tests of eer!es 6, the firet teets conducted In thleprogram, lmock polnte were obtained at five values of conetant man-ifold preesure. In this series internal-coolantflowwae graduallyinoreased to supprees knock ae the mmlfold pressure wae raieed tothe desired value. Mhen the deeired manifold preseure was obtained,internal-coolantflow wae decreaeed until knock was obeerved.

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!NACA M? ~0 . E5F30

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. lh the subsequent tests (eYery_serleb excepti6) knock oumca .were obtained at eaoh of several mnstant Internal-dob.bt, floksby mqintaln+ng tlwdeslred internal-coolantflow while we qwnlfoldpressure ma in,breaseduntil knock was.obeerved. This method wasused beoause It was found to offer simpler control feat~es thanthe first mstho~. “ . .

.

B all +ests the fuel-air mtio MS held within the.desiredrange by mnlpulatlon of the’alr-bleed valve oonnectjed-acrosstheCarburetor-alr diaphragm, T& dqta were taken at a medium knockintensity;.~t 1s, when the oscilloscope”lndloat6d-that -e to”five cyltnders were knocking. . . .

..

The following erglne’conditionswere mintalned during alltests:

Englnespeed, rpm. . . . ~. . . . . ;. . . . . . . . . 3000&ExtermQ coolant-out temperature, OF . . . . . . . . . . . 250 L5011-in temperature, oF : . . . . . . . . . . . . . . . ..170~5Spark advance, deg B.T.C. .Exhaust. . . . . . . . . . . , . . . ;. . . . . . . :. 34Intake . . . . . . . . . . . . . . ... . . . . . . . . . 28

All tests were conducted with 28-R fuel’. ‘

RESULTS AND DISCUSSION. .

Effect of fuel-air ratio and internal-coolantflow on-knq6k-limlted performan~

— - .—. ..—.—. - Flguz’es1 to 4 presfit-~=k-limlted engineperformance~a= %?the eight series of teets ehowlng directly theeffect of.fuel-alr ratio aridinternal-coolantfl~ on the knock-llmlted.performance. The knock curves obtained considt of ammberof knock points.suffldlent only to “determinethe correct values Qfthe dependent engtne variables at a fuel-air-ratio of.O.08. ‘Thedata.therefore do not.perm~t”drawi.ngknook curves of the propercnlrvaturs,

Khook.points were obtained Without interhal.oodants eaoh daythat..testsWRrS conducted. .“Figurd1 shows the variation fn resultsobtained.without In+iernalooolantsat oar’bu%etmr-alk”teniperaturesof 1200 and 60° F. only the average curves for results withoutinternal coolant are shown In the other”flgures. During the periodin which..tbsts were..-conduoted~theknock~~imited horsepowe&s”obtaln-able without Internal coolants gradually Increased. The reason forthis increase Is not knowh.

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6 NAOA m No. E5mo

The maximum brake horsepower attained in these tests was 2310at a fuel-air ratio of 0.079 and a Carburetor-alr tanperature of60° F with 663 pounds per hour of water-ethanol Introduced with thefuel through the fuel spray nozzle (serle”s2, fig. l(b)).

Comparison of internal coolants and methods of injeotion. -The lmock-limiteciperf-~=ti~f figures 1 to 4 are oross-

.—

plotted In figure 5 as functions of internal-coolantflow at a fuel-air ratio of 0.08 and are tabulated in table I to facilitatecomparisons of the effects of the two internal coolants, methods ofinJection, and oarburetor+lr temperatures. Figure 5 shows thatneither internal coolant was at all conditions more effective thanthe other in raising the hock-limited brake horsepower.

The following table shows the conditions at which eaoh internalcooht was more effective than the other:

Carburetor-air Meana of Internal-coolaxttempwature

(w)injeotlon flowra~r)

120 : Fuel nozzle 0-530530-ma@

120 Spray jets 0-710710-maxa

60 Fuel nozzle Entire range60 Spray”jets 0410

410-ma+

Superior Internalcoolant

- .——...— —

WaterWater-ethanol

WaterWater-ethancl

Do.Water

Water-ethanol

%x indioates the ~ximum internal-coolantflow used In each case.

Introduction of the internal coolant through the fuel nozzlegenerally Increased the knock-limited brake horsepower more than itsintroduction through the intake-manifold spray Jets. With the sameconditions of Internal-coolant injection, lowering the oarburetor-air temperature from 120° to 60° F raised the knock-limlted brakehorsepower In all oases.

on all curves of mixture temperature against internal-coolantflow (fig. 5) there is a point beyond whioh”an increase in internal-coolant flow does not serve to lower the measured mixture tempera-ture. TMs leveling of the curves is due to the fact that, asInternal-coolantflow is increased, an increasing amount of internalcoolant is osrried past the mlrture-temperature thermocouple beforevaporizing.

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NAOA m lvo. E5mo 7

ComplrIson bf methods”of ltirl~ mixture temperature. - lYg-ure 6 compares the effects on lmock~lititeilbrake horsepower andmanlfold pressure of lowering t~ mtxture”temperature by inte”rna~ooolante and by lowering the carburetor-air temperature. Curvee for “Internal-coolant lnJectim have been cross-plotted at a fuel-airratio of 0.0f3from figuree 1 to 4 and curves for varia~l.eoarburetor-air temperature f~]a unpublished data have been added for ccniparleon.The vertloal parts of the curvee’fortfiel-nozzle in$ection in fig-ure 6 result from the faqt that, when the $nternal-coolantflowsreached certain ,valuea,hcreases in Intbimal-coolantflow failed tolower the meaeured mixture temperatures. Exc$eptat the low mixturetemperatures, the knock-limited brake-horsep~r ourves for fuel-nozzle in~ec!tlon”lnf@ure 6 follow cloee~ the curves for variablecarburetor-air“temperat~. This agreement indicates that the effectof water or water-ethanol on hock-limited brake horsepower Ispri~lly one of coollng the mtxture.

Figure 7, cross-plotted from figure 6,.shows the relationbetween knock-limlted brake horsepower and nmnifold pressure withand without Internal coolants. ~ engine was maintained at theknock limit over.the power range In one case by varying thecarburetor-air temperature without Internal ooolants and, in theother caeee, by varying the Internal-coolantflow rates withconstant carburetor-airtemperature. Figdre 7 shows that exceptat some of the lower Internal-coolantflows a higher manifold pres-sure Is required to obtain a given bock-llmlted brake horsepowerby means of Internal-coolant inJectlon than by means of loweringthe carburetor-air tempemture.

Horsepower correction for puwer required to supply highcarburetor-inlet pressures. - Carburetor-inlet static pressuresgreater than eea-level wessure were required and were sumlled by&e laboratory refriger~ted-air eyetem ~or all tests In which the-manlfold pressuz% was higher than approximately 70 Inches of mercuryabeolute. The data for lmock-limited brake horsepower sham In .flgurea 1 to 7 hays not been aorrected for the power required tosupply carburetor-inlet statlo pressures greater tliansea level.

Calculations, presented in the appendix, have been mde todetermine the approximate puwer required to supply carburetor-inletstatic pressures higher than sea level used in each series of tests.The calculated powers have been subtracted frcmthe hook-ltiltedbrake-horsepower data of figure 5 and the resulting correc~ed curvesare pmnted in figure 8 together with the unconwcted curves .traoed from figure 5. From the curves of figure 8 it Is evident

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8 .N4CA MR No”. E5e30

that the correction ohangea only slightly the comparisons M theeffects of the two Internal.coolants, methods of InJection, andcarburetor-air tempezaturee.

SUMMARY

The followt~ resuits werethe effect u: internal coolants

OF RM3U’LTS

obtained from teats to determineon the hock-limited Performance of a

V-type 12-cylinder liquid-cooled alrcraft engine with-a 1710-cubic-inoh displacement and a compression ratio of 6.0:

1. The maxtmum knock -limitedbrake horsepower attained was2310 at a fuel-air ratio of 0.379 and a carburetor-alr temgsratureof 60° F with 663 pouuds per hoti of water-ethanol Introduced withthe fuel through the fuel-spray nozzle.

2. In generaI, at low internal-coolantflows or at the highcarburetor-air temperature, water was more effective than water-ethanol in raising the knock-limited brake horsepower. As theinternal-coolantflow was Inoreased or the carburetor-air temper-ature decreased, water-ethanol becaniemore effective than water.

3. Fuel-nozzle Inflectionof a given intezmal coolant at agiven carburetor-air temperature was generally more effective Inraising the knock-limlted brake horsepower tham Injection throu@intake-mantfold spray $ets. “

4. Except at some of the lower Internal-coolantflows a hi@ermanifold pressure was required to obtain a given knock-limited br&ehorsepower b$ means of internal-coolant Injection than by means ofloweri~ the carburetor-air temperature.

Aircraft Engine Research laboratory,”National Advisory Committee for Aeronautics,

Cleveland, Ohio, Juns 30, 1945.

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NAOA m HO. HF30” 9

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Amm’mIx -cALcuIATIoNoFm REQumED TosuPPLYcAmJRmm-.

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Carburetor-hl.et statlo pressures greater than sea level wereneoeaeary for all teats In whioh t@ manifold pressure was greaterthan approximately 70 Inohes of merourg absolute. Figure 9 ehomthe relation between manifold pressure and the required carburetor-inlet statlo pressure at wide-open throttle for each series ofteBtB. The power required to ~oduce these oemburetor-inlet pres-sures was supplied by the Mmrcitory refrl~erated+ir system. Muchof the knock liulitedbrake-horsepower data of flgures”l to 7 aretherefore higher than they would have been had the engine beenoharged with ”thepower required to supp~ high Oarturetor-inletpressures.

Calculations have beenmde to determine the approximateknock-limited brake horsepowers that would have been obtained ifthe engine had been equfpped to supply Its own high oarburetor-inlet pressures.

It was asbumed that:.

(a) The Inoreased carburetor-inletpressures were obtainedfrom an auxiliary-stage superchargerand the air leaving thissuperchargerwas oooled by an Intercooler so that the temperaturesat the carburetor inlet were held constant at 120° and 60° F.

(b) Themaximum intercooler effectivenesswas O.6.

(c) The temperatures of the Intercooler cooling air and theair at the entrame to the auxlli~-stage superchargerwere bothconstant at 95° and 35° F in order to obtain carburetor-inlettemperatures cd?120° and 60° F, respectively. Intercooler dragwaB nsgleotbd.

(d) Interoooler oooling-air fluw was varied by means of flapsin order to maintain oongtant carburetor-inlettemperatures withvariable temperature rise throu@ the auxilia~-stage supercharger.

(e) The ~ge-air pressure drop aoross the interoooler wasin all oaqes 1 inoh of wrc~o .

(f) The tilabatic efficlenoy of the auxiliary-st~e super-charger was 68 pbrcent.

(g) The meohanioal effioie~ of the auxiliary-stage super--r drive was 9S ~eroent.

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10 l“uusAMR No. IHl?qo

~.foll~~,eqmtlmns-then used to determine auxiliary-stage supercharger horsepowers:

[( 1,-~-~“7RT”P2)y-1

7 -1 1 q..)

hp=— — —.———:—.. .550 ~ad ~

wkere

w

?’

R

‘1

P2

Pl

qad

%

charge-al=. fiuu, 1%/wc

specific-heat ratio far air, 1.39,.

gas constanz,.53,’.5fb-lb/(lb)(oF)

auxtiliary-stagesu~9ncharger entrance tgmpelature, %

auxlllary-stag~ superchm’ger owclet prepmure, in. ~ absolute

[P2 = Carburmtorslnlet static pressure required, in. Hg

ab=~ltlla(from fig. 9) + intercooler pressure drop(1 I?i.m)j . .

atmospheric pressure, 29.92 In. I@ absolute,.

adiabatic efficiency, 68 percent..

mechan~cal efficiency of drive, 9“5percent . . .

The.hcrsepo%mre.obt@@ad from this equation were subtractedfrom the knock-limited brake-horsepower data of fl~re”5 and the “resulting corrected knock-llmlted brake-horsepower curves are.shcwhIn figure 8 toge%her with the unco~ected curves traced fromfigure5. . .. . “’. .. .

....” ,.”: . .. . . . .

~m. . “ . . .

1. Harries, ~ron L., Nelson, R. Lee, and Ilerguson~H~rd EO:mlMfect of Water InJecticm”on ~ck-Limited Per20rmnce ofa V-!QPS 12-Cylinder Liquid-Cooled Engine. NAM Meti+ repa~Sept. 9, 1944.

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km MR mom E5mo 11

-1 -~~mCK—LIMTEDH!RKnWMcE ‘

WIm AND WITHOUT INERNAL COOLANTS

[V-t~ 12-oylindEIrllquld-oool.edengine; engine speed, 3000 qm;compression matio, 6.0; fuel, 28-R; fuel-air ratio, 0.08]

TMeahs of Internal-Internal- coolantcoolant flowln~eotlon (lb~)

Incr6ase\

T,“&?%ld Incr-~pressure over(in. Hg manifoldabsolute).pressure

withoutinternalCoolfultercent

IW.

rInternalCoolerltBrakehorse-power

over bhpwithoutinternalCooleurt(percent)

.~I temperature,12(-— A.

T52.7 --------.

61.2 16.172.5 37.69.8 51.4 -52.7 --------.56.6 7.463.4 20.3

Ili75 --”-----.1450 23.4lmo 50.6I ‘t-ll ‘“1° I ::

lkEd5-19701175

-JizL-“----- -.

9.826.049.4.—

---------.40.454.063.8.—

--------.24.740.0

12901480LGAF-K-1755-—1175 -+%-t++

I nozzle 200400600

Intake- 0manifold 200spray 400Jets 600

Carburetor-al

Water- Fuel 0ethanol nozzle 200

400600

lixhake- 0=Ifold 200spray 400J-etB 600

Water Fuel 0nozzle 200

400

--t--

67.5 28.173.5 39.58.2 48.4

52.7 -------.I

63.0 19.670.1 33.0

+’ 45’2

1650181019251175146516451795 I 52.8

Itemnmture. 6(

1520180520302230——1520167018402020152017801950

----1-----.----63.1

18.7 71.233.5 79.1

. 46.9 86.8--------- 63.1

9.9 67.4

i---

21.0 73.832.9 80.2

-:------- 63.117.1 70.828.3 75.6

------- -,

12.825.4

_.QZ&--------!

6.817.027,1——

--------!12.019.8

I l===-F%- 2C)1O1520 ! 32”2 !%+’+++----------

LE?l_E- 1740I

14.5I

70.5 I 11.71840 21.0 74.4 17.91940 I 27.6 i 78.5 I 24.4

National AdvlBory Oommlttee for Aeronautloa

b

.●.

MACA UR MO, E5F30

22fM

(a) Carburetor-air teqmmtum, 120° F.

-1. - Khock-limlted data with a S0-50 mixture by Yolum of water-et-l Introduced withfuel through fuel nozzle. V-type IZ-cylinder llquid-ccmled engim; OWIIN, roped, J3000Jrp;mmpmmmion mtio, 6.0; fuel, 28-R.

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NACA MR Ho. E5F30

NATIONAL ADVISORY1, 1 r 11 , , , I I , I 1 , I 1, 1 , -I -

COMMITTEE FOR AERONAUTICS

24-C

o,.0

j.al 20C

:

Lae

$ *x

: 16C

$.z JU L1 /

12a“

:90 6* ~

.

.S

t!-80 -wv-.-! .

-70

4 -r+

-60

Internal-& coolant flow

(lb/hr ):G 2400,50 2O,oco

o 0

\; #

YZ _

2200 v 663 1a ,0000

1?D 2000—

; :.-lEJ

~ *s.

y9 -x~ . . . _ _ _ _ ~1 AC 7_

5~ L9co k x

0 al

z + E?

1600

125-21:1400 10,Oco

.07 .06 .09 .07 .0.5 .OqFuel-air rat 10

. -.,

(b) Carburetor-air temperature , &)” F.Figure 1. - Concluded.

MACA MR HO. E5F30

NATIONAL ADVISORY1

C0W17TEE FoR AERONMJTIcs

:9

t%’.

alhs.:

2.~

4%dGz~

c: 50.x +=

coolant flow

o

2000

L30

3916:~

4-C +

,+❑

:*

#lb-&l *

2x

m.07 .Oa .09 ,07 .M .09

Fuel-alr ratio

(a) CarburutOr+Ar toqa-atnre, 120° F.

Fi6um 2. - Knock-1imited data with a 50-50 mixture by volumethmqlb spiny jets in intake manifolda. v-type I.Z-cyllmrcompmm!ion ratio, 6.0; fuel, 28-R.

of vater-ethmol introducedliquict-ooaledengine; engine sped, 30c0 W;

NACA MR NO. E5

NATIONAL ADVISORYCWITTEE FOR AERONAUTICS

.wuld.cl

$’ g6.~1e-=: .-l

ZZ7$:

x’ Series 4 :0C4 c2 Internal- 0

-+ ~

coolant flew 4J

60: (lb/hr ) 2c

— 10:+

240

~po

2D200Q:iq

0

L

160

1400.07 .08 .09 .07 . OIJ .09

IF30

Fuel-air ratio(b) Carburetor-air temperature, 600 F.Figure 2. - Concluded.

liACA MR HO. E5F30

2

2

1

1

NATIONAL AOVISORYCOMMITTEE FOR AERONAUTICS

9

8

K.

+23

.s

6

.2

.07 .08 .09

12 I I I

.07 .06 .09Fuel-sir ratio

(a) Culmrd.or-air tempemtum, 120%.

?igum 3. - lhxk-limltd data with ~ter introduced with -l through fuel nozzle.V-typm 1.2-oyllmier liquid-cooled omgi.m; englrn npeed, 3000 rpm; compression ratio,6.0; fad, 28-R.. .. .. . .....

MACA MR No. E5F30

1

(bF1

, , 1,, r! , ,,, 1,,, ,,1I ,,NATIONAL AOVISORY

mll f

CWITTEE FOR AERONAUTICS

40

20

Variable (no internal coolant)

o

!200 lad

!000- 4- 16.(x o 4 \

% - 1-2>.-4 S% yp_- .

Y g-.goo: L ,-4 14.Qf9 4.

7 ~i

,600-

i f 126-17:

.07 .011 .09 .07 .im .09Fuel-air ratio

) Carburetor-air temperature, @o F.gure 3. - Concluded.

NACA MR No. E5F30

NATIONAL ADvISORY , , t , , r , I , , , , m 11, , f

COMMITTEE FOR AERONAUTICS

.,

*

J!.

m-Lgm. . t * *

1

1

1.07 . Og .09 .07 . oi3 .09

Fuel-air ratio

(a) Carburetor-alrtempantura, 120° Fe

Fi@re 4. - ~ock-llmltad data with water intrmluced through sprayjets in htaks manifolds.V-type 12-cyllnder liquid-cooled engine; englna speed, 3000 rpm; ccmpraeslon ratio, 6.0;

Ifuel, 28-R.

IIACA MR !to. E5F30

NATlONAL ADVISORYCOMMITTEE FOR AERONAUTICS

.;m

#● 90

.5.

alh3umw&

“ A •1

TJ

Fuel-air ratio(b) Carburetor-air temperature. 600 F.Figure k. - Concluded. -

MA,CA

M

, 16

14

10

.5

I MR No. E5F30

,000NATIONAL ADVISORY

COMMITTEE FOR AERONAUTICS

~

,000 .

,000 .

Series Internal coolant Meana of injection

—1 Water-ethanol Fuel nozzle----- 3 WatePethanol Intake-~anlfo16 spray jets

,000 —-— 5 Water Fuel nozzle---— 7 Wet ●r Intake-!rmnifold spray Jets

,000 ~

\lilo-

\2000

{ \/ / \

/

f / < -— . \14’o-

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.

a

I.- 1 1 L 1 1 1 1 I ,

1200

10300 2Q0 w 600 600 0 200 400 600 am

Internal-coolant flow, lb/hr

(8) Carhrator-air tamperataue,120° F.

?igal’e5. -Effect of internml-coolentflue on knock-limitedperformance. V-type 12-cyli!xlerll~uld-ccoledengb; engirn spad, W303 rpm; cmpreaalon ratio, 6.0; fuel, 28-R. Crosn plot at a fiel-alrmtio of 0.08.

MACa MR NO. E5F30

NATIONAL AOVISORY111> , 11 , I , r 11 # r,, 1 ,1 ,

COMMITTEE FOR AERONAUTICS

20,000 - — — — — — — — — — — — — — — — -

18,000 ,

~ {

5 16,000g-~

Ad

i

L~ u

!% alha

m~: L.-lc.am xE$

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o 200.400 6oa kooInternal-c~o~ant Oflow, Ibn&

600 goo

(b) Carbur:tm&:d:::perature, 601J F.FigOre 5.

NACA MR MO. E5F30

..

NATIONAL ADVISORY3

COMMITTEE FOR AE~N~Tlcs

/

go-r

Series Internal coolant Carburetor-airtem~t.re

None Variable---- 1 Water-ethanol 120—.— 5 Water 120

22Qq

1.s00

Ba*mZ 16:q+0

~1

1

1

120 160 200 240 ?60 ymMixture temperature, ‘F

FiSUI’O6. - Effect of mlxturati~raturecm knmk-llaitd perf ~w with ad without lntenialcoolantm. V-t~ lZ-cylin&r liQuicl-coolademgirn; engina qnwd, 30CX3~; ccqmaaion ratio, 6.0;fuel, 28-R; fuel-nozzle titerml-ooolant im@Otlm. Croee plot at a fuel+m mtio of 0.08.

NACA MR NO. E5F30

I, r l“’’I’’’’ 1’’’’ 1’’’’ 1’’’’ 1’””4\NATIONAL ADVISORY

–r-r 1v Ir,l 1111 1111 1

COMMITTEE FOR AERONAUTICS

.;

.5

.

:

wk:

$ 608CI:~

+

2U Serlea Internal coolant

40 .tem~g;;ture

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==--i-!L

None Variable.?400: —.— . Water-ethanol 60—-— z Water 60

2200 - 1

\\\

I\

2000 -\

\ \

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1400

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1.20 160Mlxtu$?tempera~~e, OF

2Eio 320

Figure 6. - Concluded.

MR ttO. E5F30NACA

,

1“’’l’’’’T’’’’l’T’l’’’’l’’’T’’’]NATIONAL ADVISORYCOAWITTEE FOR AERONAUTICS

I I I -1’1 I 1’/’1- I “1”””1 1“1 i I I 3I I I 1 I I I /1 I I I I I I I I 3

Wata~ethanol Fuel nozzleWater-ethanol Intake-manifold

eal

~2

&0~

2

u

16

1

.

1----- i Water-ethanol Intake-manifold ~

1

40 50 64 70 80 wInook-ltiited mnlfold pressure, in. Hg abc.

- 7. - Relation botv.en kmck-ltiit.ed brakm horaepowr and -fold -ssum with constantknock-intenoity rnlntaiIA by Yarlntion of intinml-coolnnt fla or by mriat ion of carburetor-●ir temperattuw. V-typa E?-oylimler liquid-cooled engine; engine speed, 5000 ZT’O;ocqresaicnmtio, 6.0; fuel, 28-R. cross plot at a i’uel+ir mtio of 0.06.

.—

NACA MR No. E5F

Unto -ret’ edNATIONAL ADVISORY

COMMITTEE FOR AERONAUTICS

m

1600

2000

1600

1600

aooo /

&D?.QiN~ /

5: 1200

iltmu0

21000

Internal coolant Mean6 of injection

Moo

/

.. —- 3 Water-ethanol Intake-man% fold spray Jets—-—

/5 Water Fuel nozzle

2000 ,___— Water Intake-manifold 9Drey jets

1800 -

1600

XIM

1200

1000 200 400 600 800 1000

Internal-coolant flow, lb/hr

(a) Cerburctor-eirtemperetura, 120° F.

30

FiBUIW 8. - Variation of corrected and uncorrected kncck-llmlted bralm hcraapcwer with interml-ccmlent flm. V-type 12-cyllnder llquld-cocled englm; engine speed, 3000 rpm; ccagrafmicn mtic,6.0; fuel, 28-R. Cross plct at a fuel-air mtio of 0.08.

HACA MR No. E5F30r r r r , , , , 1 1 , , , i

NATIONAL ADVISORY

z~ .COMMITTEE FOR AERONAUTICS

/

ZQm /

2!!hw2

-1

2DO0

11300/

& / SeriesP

Internal coolant Means of injection/

~ // Water-ethanol Fuel nozzle

0 .— ---: 1600 -zzQo / j Water-ethanol Intake-manifold spray Jets

—-— Water Fuel nozzle0 Water+ /

—.-— 6 Intake-menlfold spray Jets

g

2u

1400 -/ e

u- ~ d

.

/ >“.

~Corr?Cted

-Moo/

/

-16

2200

-1400 u~ a Led,.fl

2000“ / U Ca12m-

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/ 416c4J- /

126.54 :31, N , , , ,, , * ,,1 , 1 t1,1 111 11,I 111I 14I* ,,11 ,1,1 ,I1la 1 II1

0 200 400 .600Internal-coolant flow, lb~~

1000

(b) Carburetor-air temperature, 600 F.Figure g. - Concluded.

MACA MR No. E5

11 1 , , , , , , , , 1, w!NATIONAL ADVISORY

I 1t . ,

40COMMITTEE FOR AERONAUTICS

Sert es/

Serif 18

35 / ‘

1 5/ ‘

30

* !

40:

●

:

.5

ui

mmhE2

m

w

z40 :

f!2@

~

*

rE

3

Knock-limltad menlfold pressure, in. Hg abs.

~igure 9. - Raqulmd oarbumtor-inlet atatio pmsaum at -Ida+penthrottleaneifunotionknook-iimitad~fOld P89u19 . V-type lZ-cylixmlerliquid-oooled engim; engine opeed,3000 rpm; capremeica mtio, 6.0; -1, 28-R.

F30

or

—- ... -. 1

Illllllllllmflllllmlllll_~117601354 1967

,)

.