1、Designation: D909 14 Method 6012.6Federal TestMethod Standard No. 791bDesignation: 119/96Standard Test Method forSupercharge Rating of Spark-Ignition Aviation Gasoline1This standard is issued under the fixed designation D909; the number immediately following the designation indicates the year oforig
2、inal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department
3、of Defense.1. Scope*1.1 This laboratory test method covers the quantitativedetermination of supercharge ratings of spark-ignition aviationgasoline. The sample fuel is tested using a standardized singlecylinder, four-stroke cycle, indirect injected, liquid cooled,CFR engine run in accordance with a d
4、efined set of operatingconditions.1.2 The supercharge rating is calculated by linear interpo-lation of the knock limited power of the sample compared tothe knock limited power of bracketing reference fuel blends.1.3 The rating scale covers the range from 85 octanenumber to Isooctane + 6.0 mL TEL/U.S
5、. gal.1.4 The values of operating conditions are stated in SI unitsand are considered standard. The values in parentheses are thehistorical inch-pound units. The standardized CFR enginemeasurements and reference fuel concentrations continue to bein historical units.1.5 This standard does not purport
6、 to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in
7、Annex A1.2. Referenced Documents2.1 ASTM Standards:2D1193 Specification for Reagent WaterD2268 Test Method for Analysis of High-Purity n-Heptaneand Isooctane by Capillary Gas ChromatographyD3237 Test Method for Lead in Gasoline byAtomicAbsorp-tion SpectroscopyD3341 Test Method for Lead in GasolineIo
8、dine Mono-chloride MethodD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4175 Terminology Relating to Petroleum, PetroleumProducts, and LubricantsD5059 Test Methods for Lead in Gasoline by X-Ray Spec-troscopyE344 Terminology Relating to Thermometry and Hydrom-etryE456 Terminolo
9、gy Relating to Quality and Statistics2.2 CFR Engine Manuals:3CFR F-4 Form 846 Supercharge Method Aviation GasolineRating Unit Installation ManualCFR F-4 Form 893 Supercharge Method Aviation GasolineRating Unit Operation it is the softest knock that the operator can definitely andrepeatedly recognize
10、 by ear although it may not be audible onevery combustion cycle (intermittent knock). The variations inknock intensity can occasionally include loud knocks and verylight knocks. These variations can also change with mixtureratio; the steadiest knock typically occurring in the vicinity of0.09 fuel-ai
11、r ratio.3.1.11 power curve, nfor supercharge method knockrating, the characteristic power output, expressed as indicatedmean effective pressure, over a range of fuel-air ratios fromapproximately 0.08 to approximately 0.12, when a superchargetest engine is operated on isooctane plus 6 ml of tetraethy
12、lleadper U.S. gallon under standard conditions at a constant intakemanifold pressure of 40 in. of Hg (134.3 kPa) absolute.3.1.12 knock-limited power curve, nfor superchargemethod knock rating, the non-linear standard knock intensitycharacteristic of a primary reference fuel blend or a samplefuel, ex
13、pressed as indicated mean effective pressures, over therange of fuel-air ratios from approximately 0.08 to approxi-mately 0.12.3.1.13 reference fuel framework, nfor superchargemethod knock rating, the graphic representation of the knock-limited power curves for the specified primary reference fuelbl
14、ends of isooctane + n-heptane and isooctane + TEL (mL/U.S.gal) that defines the expected indicated mean effective pressureversus fuel-air ratio characteristics for supercharge test enginesoperating properly under standardized conditions.3.1.14 mean effective pressure, nfor internal-combustionengines
15、, the steady state pressure which, if applied to the pistonduring the expansion stroke is a function of the measuredpower.73.1.15 indicated mean effective pressure, n for spark-ignition engines, the measure of engine power developed in theengine cylinder or combustion chamber.3.1.16 brake mean effec
16、tive pressure, n for spark-ignitionengines, the measure of engine power at the output shaft astypically measured by an absorption dynamometer or brake.3.1.17 friction mean effective pressure, n for spark-ignition engines, the measure of the difference between IMEPand BMEP or power absorbed in mechan
17、ical friction and anyauxiliaries.3.1.18 repeatability conditions, nconditions where inde-pendent test results are obtained with the same method onidentical test items in the same laboratory by the same operatorusing the same equipment within short intervals of time. E4563.1.18.1 DiscussionIn the con
18、text of this method, a shorttime interval is understood to be the time for two back-to-backratings because of the length of time required for each rating.3.1.19 reproducibility conditions, nconditions where testresults are obtained with the same method on identical testitems in different laboratorie
19、s with different operators usingdifferent equipment. E4563.2 Abbreviations:3.2.1 ARVaccepted reference value3.2.2 ABDCafter bottom dead center3.2.3 ATDCafter top dead center3.2.4 BBDCbefore bottom dead center3.2.5 BMEPbreak mean effective pressure3.2.6 BTDCbefore top dead center3.2.7 C.R.compression
20、 ratio3.2.8 FMEPfriction mean effective pressure3.2.9 IATintake air temperature3.2.10 IMEPindicated mean effective pressure3.2.11 NEGNational Exchange Group3.2.12 O.N.octane number3.2.13 PNperformance number7See The Internal-Combustion Engine by Taylor and Taylor, InternationalTextbook Company, Scra
21、nton, PA.D909 1423.2.14 PRFprimary reference fuel3.2.15 RTDresistance thermometer device (TerminologyE344) platinum type3.2.16 TDCtop dead center3.2.17 TELtetraethyllead3.2.18 UVultra violet4. Summary of Test Method4.1 The supercharge method rating of a fuel is determinedby comparing the knock-limit
22、ed power of the sample to thosefor bracketing blends of reference fuels under standard oper-ating conditions. Testing is performed at fixed compressionratio by varying the intake manifold pressure and fuel flowrate, and measuring IMEP at a minimum of six points to definethe mixture response curves,
23、IMEP versus fuel-air ratio, for thesample and reference fuels. The knock-limited power for thesample is bracketed between those for two adjacent referencefuels, and the rating for the sample is calculated by interpola-tion of the IMEP at the fuel-air ratio which produces maximumpower (IMEP) for the
24、lower bracketing reference fuel.5. Significance and Use5.1 Supercharge method ratings can provide an indication ofthe rich-mixture antiknock performance of aviation gasoline inaviation piston engines.5.2 Supercharge method ratings are used by petroleumrefiners and marketers and in commerce as a prim
25、ary specifi-cation measurement to insure proper matching of fuel anti-knock quality and engine requirement.5.3 Supercharge method ratings may be used by aviationengine and aircraft manufacturers as a specification measure-ment related to matching of fuels and engines.6. Interferences6.1 PrecautionAv
26、oid exposure of sample fuels to sunlightor fluorescent lamp UV emissions to minimize induced chemi-cal reactions that can affect octane number ratings.86.1.1 Exposure of these fuels to UV wavelengths shorterthan 550 nm for a short period of time can significantly affectoctane number ratings.6.2 Elec
27、trical power subject to transient voltage or fre-quency surges or distortion can alter CFR engine operatingconditions or knock measuring instrumentation performanceand thus affect the supercharge rating obtained for samplefuels.7. Apparatus7.1 Engine Equipment9,10This test method uses a singlecylind
28、er, CFR engine that consists of standard components asfollows: crankcase, a cylinder/clamping sleeve, a thermalsiphon recirculating jacket coolant system, an intake air systemwith controlled temperature and pressure equipment, electricalcontrols, and a suitable exhaust pipe. The engine flywheel isco
29、nnected to a special electric dynamometer utilized to bothstart the engine and as a means to absorb power at constantspeed when combustion is occurring (engine firing). See Fig. 1and Table 1.7.1.1 The single cylinder test engine for the determinationof Supercharge rating is manufactured as a complet
30、e unit byWaukesha Engine, Dresser, Inc. The Waukesha Engine desig-nation for the apparatus required for this test method is ModelCFR F-4 Supercharge Method Octane Rating Unit. All therequired unit information can be found in the SuperchargeMethod Aviation Gasoline Rating Unit Installation Manual,CFR
31、 F-4 Form 846 and the Supercharge Method AviationGasoline Rating Unit Operation intake valve opening and exhaust valve closing.10.2.4.1 Intake valve opening shall occur at 15.0 6 2.5BTDC with closing at 50 ABDC on one revolution of thecrankshaft and flywheel.10.2.4.2 Exhaust valve opening shall occu
32、r 50 BBDC onthe second revolution of the crankshaft and flywheel, withclosing at 15.0 6 2.5 ATDC on the next revolution of thecrankshaft and flywheel.10.2.5 Valve LiftIntake and exhaust cam lobe contours,while different in shape, shall have a contour rise of 8.00 to8.25 mm (0.315 to 0.325 in) from t
33、he base circle to the top ofthe lobe.10.3 Assembly Settings and Operating Conditions:10.3.1 Spark Advance, constant, 45.10.3.2 Spark-Plug Gap, 0.51 6 0.13 mm (0.020 6 0.003in.).10.3.3 Ignition Settings:10.3.3.1 Breakerless ignition system basic setting for trans-ducer to rotor (vane) gap is 0.08 to
34、0.13 mm (0.003 to 0.005in.).10.3.4 Valve Clearances, 0.20 6 0.03 mm (0.008 6 0.001in.) for the intake, 0.25 6 0.03 mm (0.010 6 0.001 in.) for theexhaust, measured with the engine hot and running at equilib-rium under standard operating conditions on a reference fuel of100 octane number at the fuel-a
35、ir ratio for maximum powerand an absolute manifold pressure of 101.6 kPa (30 in. Hg).10.3.5 Oil Pressure, 0.41 6 0.03 MPa (60 6 5 psi) gage inthe oil gallery leading to the crankshaft bearings.10.3.6 Oil Temperature, 74 6 3C (165 6 5F) at theentrance to the oil gallery.10.3.6.1 Engine Crankcase Lubr
36、icating Oil Level:(1) Engine Stopped and ColdOil added to the crankcaseso that the level is near the top of the sight glass will typicallyprovide the controlling engine running and hot operating level.(2) Engine Running and HotOil level shall be approxi-mately mid-position in the crankcase oil sight
37、 glass.10.3.7 Coolant Temperature, 191 6 3C (375 6 5F) in thetop of the coolant return line from the condenser to thecylinder.10.3.8 Fuel Pump Pressure, 0.10 6 0.01 MPa (15 6 2 psi)in the gallery.10.3.9 Fuel Injector Opening Pressure, 8.2 6 0.69 MPa(1200 6 100 psi) for Bosch nozzle; 9.9 6 0.34 MPa(1
38、450 6 50 psi) for Ex-Cell-O nozzle.10.3.10 Fuel Injector TimingThe pump plunger mustclose the fuel-inlet port at 50 6 5 ATDC on the intake stroke.10.3.11 Air Pressure, 0.37 6 0.003 MPa (54.4 6 0.5 psi)absolute at the upstream flange tap of the air flow meter.10.3.12 Air Temperatures, 52 6 3C (125 6
39、5F) in thedownstream leg of the air-flow meter and 107 6 3C(225 6 5F) in the intake manifold surge tank.TABLE 1 General Rating Unit Characteristics and InformationCylinder 7.0 : 1 C.R. - FixedStandard Bore, in. 3.25Stroke, in. 4.5Displacement, cu in. 37.33Valve gear enclosedRocker arm bushing needle
40、Intake valve plain with rotatorExhaust valve sodium cooled with rotatorValve felts both valvesPiston aluminumCompression rings:Type keystoneNumber required 3Oil control rings:Type keystoneNumber required 2Crankcase CFR48Rotating balance weights CFR48, non-leadedversionCamshaft, deg overlap 30Ignitio
41、n capacitor dischargeSpark plugType AviationGasket solid CopperHumidity control compressed airFuel system manifold injectionPump timing inlet port closes at 50 5deg ATDC,intake strokeInjection pump:Plunger diameter, mm 8Lift at port closure, in. 0.100 to 0.116Injector Pintle typeInjector lineBore, i
42、n. 1/8Length, in. 20 2TABLE 2 Specifications for ASTM Knock Test Reference FuelsASTM Isooctane ASTM n-Heptane Test MethodIsooctane, % not less than 99.75 not greater than 0.10 ASTM D2268n-Heptane, % not greater than 0.10 not less than 99.75 ASTM D2268Lead Content,g/galnot greater than 0.002 not grea
43、ter than 0.002 IP 224/02TABLE 3 Blends of Isooctane+6.0 mL TEL per U.S. GallonmL Isooctane +6.0 mL TEL perU.S. gallonmL Isooctane mL TEL perU.S. gallon0 4800 0.00400 4400 0.501000 3800 1.251600 3200 2.002400 2400 3.003200 1600 4.004800 0 6.00D909 14510.3.13 Intake Air Humidity, 0.00997 kg of water/k
44、g (max)(70 grains of water/lb) of dry air.10.3.14 Standard Knock Intensity, light knock as determinedby ear. In determining the light knock point, it is advisable toadjust first to a fairly heavy knock by varying either themanifold pressure or the fuel flow, return to knock-freeoperation, and finall
45、y adjust to the light-knock conditions.Light knock intensity is a level definitely above the commonlydefined least audible “trace knock;” it is the least knock that theoperator can definitely and repeatedly recognize by ear.10.3.15 Satisfactory Engine ConditionThe engine shouldcease firing instantly
46、 when the ignition is turned off. If it doesnot, operating conditions are unsatisfactory. Examine theengine for defects, particularly for combustion chamber andspark plug deposits, and remedy such conditions before ratingfuels.10.3.16 Crankcase Internal PressureAs measured by agage or manometer conn
47、ected to an opening to the inside of thecrankcase through a snubber orifice to minimize pulsations, thepressure shall be less than zero (a vacuum) and is typicallyfrom 25 to 150 mm (1 to 6 in.) of water less than atmosphericpressure. Vacuum shall not exceed 255 mm (10 in.) of water.10.3.17 Exhaust B
48、ack PressureAs measured by a gage ormanometer connected to an opening in the exhaust surge tankor main exhaust stack through a snubber orifice to minimizepulsations, the static pressure should be as low as possible, butshall not create a vacuum nor exceed 255 mm (10 in.) of waterdifferential in exce
49、ss of atmospheric pressure.10.3.18 Exhaust and Crankcase Breather SystemResonanceThe exhaust and crankcase breather piping sys-tems shall have sufficient internal volume and length dimen-sions such that gas resonance does not result.10.3.19 Valve Stem LubricationPositive pressure lubrica-tion to the rocker arms is provided. Felt washers are used onthe valve stems. A valve and rocker arm cover ensures an oilmist around the valves.10.3.20 Cylinder Jacket Coolant Level:10.3.20.1 Engine Stopped and ColdTreated water/coolantadded to
