January 1945 as Memorandum Report E5A29 FOR TERNARY AND QUATERNARY BLENDS CONTAINING TXPTANE OR OTHER HIGH-ANTIKNOCK AVIATION-FUEL BLENDING AGENTS

Transcription

1 2 MRNo. E5A29 January 1945 as Memorandum Report E5A29 ESTIMATION OF F-3 AND F-4 KNOCK-LIMITED PERFORMANCE RATINGS FOR TERNARY AND QUATERNARY BLENDS CONTAINING TXPTANE OR OTHER HIGH-ANTIKNOCK AVIATION-FUEL BLENDING AGENTS By Hehry C. Barnett Aircraft Engine Research Laborato Cleveland, Ohio a NACA WARTIME REPORTS are reprints of papers originally issued to provide rapid distribution of advance research results to an authorized group requiring them for the war effort. They were previously held under a security status but are now unclassified. Some of these reports were not technically edited. All.have been reproduced without change in order to expedite general distribution. E -250

2 NACA MR No. E5A29 NATIONAL ADVTSORY COMMITTEE FOR AEROYAUTICS Amy Air Forces, Air Technical Service Command FOR TERBARY AND QUATEWmY BLEN3S COBTATMING TRIPTANE OR OTHER HIGH -ABTJXXOCX: AVIJ.TION-FUXL BLENDING- AGENTS By Henry C. Barnstt Charts are presented wh5.ch peymit the estimation of F-3 and F-4 knock-limited performance ratings for certain ternary and quaternary f ut.1 blends. Ratings for various ternary and quaternary blends estimated from these charts compare favorably wit'? experimental F-3 slnd F-4 ratings. Because of the unusual behavigr Of some of the nromatlc blends in the F-S engtne, the cnzrts for at'omatlcparaffinic blsnds are pro5ably less accurats than the charts for purely paraffinic blends. ImRODUCT ION AS part of a general program to evaluate the knock-limited performance of triptane and other nlgh-anti'mock components of aviation fuels, the Cleveland laboratory of the NACA conducted tests on the F-3 and the F-4 rating engines. The resuits of these tests have been raported in reference 1. The present report presents data of reference 1 in the fora of c3arts, which can be used to estimate the F-3 and the 3'-4 antiknock ratings for multicomponent blends of the various fuels tested. The F-4 data appearing on the charts in this report are based on the blending equation suggested in reference 2 for superchargedengine test data :

3 2 NACA MR N5. E5RZ9 c where b Pl, Pz9 Pg knock-limited indicated mean effective pressure of blend knock-limited indicated mean effective pressure of components 1, 2, 3,... N1, N2? Mg mass fractions of components 1, 2, 3,... in the blend I Equation (1) has been found to be satisfactory for blends in which all cdmponents are paraffinic and have equal concentrations of tetraethyl lead. The equation applies most generally when the test data are taken at high fuel-air ratios. With the exception, of data for one fuel in the present analysis, all of the F-4 knocklimited performance data are considered at a fuel-air ratio of The analysis of F--3 data presented herein is strictly empirical but bas been found to agree satisfactorily in most cases with the exyerimental data. The accuracy of the perforrnance charts presented was checked by testing prepared blends under F-3 and F-4 conditions and comparing the observed ratings with those predicted from the charts. TEST DATA The experimental results upon which this analysis is based are given in table I (reproduced from reference 1). No performance n w bers fn this table greater than 161 were used as w ill be indicated later. The performance numbers for the F-4 tests were estimated from a reference-fuel framework (reference 1.) consisting of imock-limitedperformance curves for $0 percent S-3 reference fuel plus 1G percent M-4 reference fuel and for S-3 reference fuel clear and with Cj.5J 1.25, 2, 4, and 6 ml TEL per gallon. The use of this method of rating instead of th.e usual procedure of direct matching was necessary because of the extensive nature of the program; complete mixture-response curves for 132 blends were obtained. For this reason the accuracy of the perfornance numbers shown in table I for F-4 ratings is largely dependent on the day-today reproducibility of the engine. The brief analysis of the results given in reference 1 indicates that this reproducibility is good at n

4 I high fuel-air ratios. Inamuch as the analysis in the present seport is concerned cnly dth at a ~iml-air rstio of 0.11, it is believed that the perfunmicc-nmbm ratings at this fuel-air ratio are reasonably accurate. Ali blends tested wer3 prepared on a voluxne bash- In order to m3ke the fiw.1 charts useful for the prediction of blends giving F-4 performance nmbers grt;ater than461 at a fuel-alr ra!;io' of 0.ll it was conaidered desircblo to extrapolate L bhs psrfomr-me curve to at Least a pcrfo-mmce nvnber of 200. This extrapolation ws made by plottirg the perfomaxe nmbers against kngck-limited "irl8ic%tecp man sffective pressure from the reference-fuel frtinewcjrk in referencs 1. (SG~ fig. 1.) Although there is a definite break in thia cune at n performance nwber of 130, the C'LLrve appesrs to be linear betvqen 130 and 161, On the assumption that th2s ligear rela-ition is true, a atraigktt line W w dram through the points at 130 and 161 and extended to a pqr- f'gmwme nmber of 200. The extr ation between 161. and 200 is ahom as a dasheo line in figme In reference 1 a dffferent mtthod of extrapolation was used performance numbers greater 1. bhan 161 (see fig. 1) ; consequentlg, the perfomance-number values above 161 in table I for F-4 ratings we not; the sane as tfiose used in prsparir-8 the psrformrznce charts ii-~ the present report. Ternary Blends As an exanlyle of the preparation of a performance chart, consider first that it is desired to know the F-3 and the F-4 perfomancq nvrnbers of all gossible ternary blends of hot-acid octane, an avirz'bfon alkylate, and a virgin bass stock. These %bee fuels were chosen because their blmding relations follow equation (1) A Pldt of composition against the reciprocal of the knock-united indicated mean effective pressure for binmy blends of-any two of these fuels will. result in a straight line. The threo binary CODbinations of these materials shown in figure 2.?he ordinate scale of this figure is a reciprocal scale used for conv-enfence in order that the indica3ed mean effective pressures c a be ~ plotted. directly. Test data for ffgure '2 were taken from table I. % I e3

5 4 NACA MR No. ESA29, In the next operation, lines of constant performance number are drawn on the plot (shown as,dashed lines, fig. 2). These lines are established by readin'g va?..ues of indicated mean effective pressure at equal incrornents of perforniance nuznber in figure 1. The data ' as shown in figure 2 are t,ke basic i.nloriition needed to establish F-4 rating lines on the final cmrt for multicomponent blends. 4# i For convenience in relat'lng composition and knock-limited performance of ternary fuel blencs all Terf'ouaince charts are prepared on triangular coordinate paper. A brief description of the use of triangular coordinate psper is given in the appendix. A more detailed description of triangular plots is given in reference 3. / The performance chart for the system of hot-acid octane, aviation alkylate, and vircin base stock is shown in figure 3. Lines of constant performance number in this figure were determined by noting the intersections of tke constant performance lines (fig. 2) with the blending, lines. For examgle, the 150-performance-nUmber line in figure 2 intersects the 737.ending line of hot-acid octane and aviation stlkylate at a composition of 52 percent hot-acid' octane and 68 pement alkylate and intersects the blending line of hot-acid octane and virgin base stock at a composition of 67 percent hot-acid octane and 33 percent virgin base stock. These two compositions were plotted on figure 3 and joined by a straight line. Any point on this line represents a blend of hot-acid octa.ne,, aikylate, and virgin base stock that will give a performance number of 150 in the F-4,engine at a fuel-air ratio of G.11. All other performance lines in figure 3 were established in the same manner; - It will be noted that the lines in figure 3 are p%e~u.el, which is true when the curves shown in figure 2 are the basis of data in this report and in referersces 4 and 5, St appears that most paraffinic fuels blend linearly at high fuel-air ratios. Even though certain constituents 'such as the aromatics or ethers did not blend linearly with paraffinic Base fuels, the prccedure just outlined for the preparation of performance-number charts is not altered. A nonlinear relation in a plot of the type shown in figure 2 results in a variation of slope with performance number on the final tri-, angular plot. (See appendix. The procedure used for determining the lines of constant F-3 performance for blends of the same fuels used in pr-eparing figure 3 \ \

6 -I_ ~ NACA br'no. E5A29 5 I P differs from that used for F-4 performance iqthat performanc- 0 numbers are plotted directly against composftioi-2 on linear coordinate paper and an estimated "best" curve is drawn through the data points to determine the binary blending relations shown in figure 4. There is nothing to justify the use of this empiriical method for dealing with F-3 ratings other th.an that the end result agrees reasonably well with-the expepimental results. One or two exceptions to this method will be pointed out later. The compositions at the intersections of a given constant performance line with the blending lines (fig. 4) were plotted on triaagular coordinate paper and joined by straight lines. The resulting F-3 performance lixies are shown in figure 5. The final chart (fig. 6) was obtained by superimposing figure 5 on figure 3. Performance charts for the following fuel constituents blended with aviation alkylate and virgin base stock (all blends leaded to 4 m3. TEZ/gal) were prepared in the sane manner and are presented in figure 7 : triptane, diisopropyl, neohexane, isopentane, benzene, cumene, mixed xylenes, toluene, and methyl tert-butyl ether. Charts I-- for hot-acid octane, triptane, diisopropyl, neohexane, isopentane, benzene, mixed xylenes, tol-uene, and methyl tert-butyl ether blended with aviation alkylate and one-pass catalytic stock are presented in figure 8. In figure 7(f) the lines showing F-4 performance numbers for cumene blends were determined by plotting peak knock-limited-power values rather than power values at a fuel-air ratio of 0.1l'. This deviation from the procedure used for all otherglots in figures 6, 7, and 8 was'necessitated by the fact that most of the mixtureresponse curves for the cumens blends tested (reference 1) intersected at fuel-air ratios between 9.10 and (See fig. 9.) The fuel-air ratio for peak knock-limited power varied between Q. 115 and G. 132 for the cumene blends used in preparing figum 7(f). No plot was prepargd for blends of cumene, aviation alkylate, and one-pass 'catalytic stock because rich-mixture peaks were not obtained for a suff,icient number of the binary blends of cumene and one-paps catalytic stock reported in reference 1, Lines of' F-3 performance for xylene blends were not plotted in figures 7(g) and 8(g) because the curve of composition against F-3 ratings for binary blends of xylene and aviation alkylate passed through a minimum. (See fig. 10,),

7 6 NACA MR Bo. E5A23 In general, data obtained on the F-3 engine fpr the aromatic blends could not be handled with complete satisfac,tion by the empirical procedure previousl-y explained, For this reason the accuracy of the lines of con&,ant F-3 perromance shown for the ammatic-faraffinic systems in figures 7 and 8 is questionable. Ri I Quaternary Bltinds The performsnce charts presented in figures 6, 7, and 8 are of inteyest primarily from considerations of maximum knock-liml.ted perf orrnance attainable with various combinations of f ne1 blending'agents and current Sase stocks. The producers of a;-iation fuel, however, are interested in the maximum knock-free power attainable with a finished blend that meets physical-property specifications for aviation fuels. In the pyescnt analysis an attempt has been made to sliow how performance biiarts can be prepared for ternary blends in which each of the components has beon isopentanized to a Reid vapor pressure of 7 pounds per squara inch, Tlye addition of isopentane to &Just the vapor pressure of the components in a system such as that shown in figme 7(a) will necessariljr affect the maximum knock-free power attainable because 02 the perfcrmance rating of isopentane relative to the ratings of the other cmgoneszts in the system. (See table 11.) In figme 7(a), for example, a blend of 58.5 percent triptar,e, 30.5 percent alkylate, and 11 percent virgin base stock has a lean-rich performanceinumber rating of 1,35/200 an& a Reid vapor pressure of approximately 3.5 pountls per square inch (estimated from table 11). In order to obtain the same porfomance (135/200) with a blend of triptane, alkylate, and virgin base stoclc that has been isopentanized to a Reid vapor pressure of. 7 pounds per square inch (lu,aximwn from specification), a blend of 55 percent tri>tane, 17 percent alkylate, 7 percent virgin base stock, an6 21 2ercent isopentane could be used. The addition of' isopentane has thus effectively 8ecreased the quantity of triptane needed to obtain the 135/200 performance rating. The reason is that isopentane has better performance characteristics than the alkylate or the virgin base stock used as well as a higher Beid vapor pressure than the other three constituents in the blend. (See table 11.1 It must be emphnsizeci that thu preceding example is merely given as a sample consideration of a fuel characteristic other than knock, which must be considered for a finished fuel blsnd. This example is not intended to imply that the preparatipn of fuel blends as presented in the present report with Reid vapor pressures adjusted to

8 meet specifications will nesesaarily produce blends that will mect all 2ertin:xL specifications. Several perfomance charts for quaternary blends containing isopentaiie verd preparsd. for comparison with tile charts described befcrs for ternary blends. In each of the quaternary systems the vapor pressre was-adjusted to 7 2ounds per square inch. Three assumptions uere made in tha preparation OP these charts: (1) The, roi.ation between composition (volume basis) and Reid vapor pessre for binary b?sncls of isopentana with another paraffinic fuel is linear. (2) The reletion between composition and ths reciprocal of the F,-4 (rich) knock-iim,.tsd indicated mean effective pressure for binary 'blends of isopentam with another. paraffiriic fuel is linear. { 5 ) The relation be.'~we~n corndosition and the F-3 performance number for binsry blends of isopentane with another pareffinic fuel is lincar. / \ h On the basis of the available data, assumption (3) appears to bo valid for only a few cases. For this reason the F-3 performance lines on the charts for quaternary blend8 may be in error. As an example of tlie prepzration of tho performance chart for a quaternary system, assume that it is desired to isopentanize the blends represented by figure 7(a). Ths first step in this problem is to determine the amount of isopentane to be addad to each of the pure components (fig. 7(a)) to obtain a Reid. vapor pressure of 7 pounds per square inch and to determino tke resultant F-3 and F-4 performance-number ratings Tor these blends. This infomation was obtained from the foregoing assumption8 and the data in table I1 and is presented in thc following table: 76% tri;?tane + 24% isopentane + 4 ml TEL/ga 1 8% alkylate + 15'tisopentane + 4 ml TEL/gal 92;o virgin base + 8$ isopentsne + 4 ml TEL//gal F-3 perform- F-4 indiance number cated mean effective pres sure (lb/sq in. ) c

9 a RAGA MR No. E5A29 The triangular chart shown in ftgure ll(a) was obtained by treating these three blends (all of which have Reid vapor pressures of 7 lb/sq in.) as separate component@ by the procedure used in preparing figure 7(a). Any point on figure ll(a) represents the F-3 and the F-4 performance number of a quatsrnary blend. The actual quantity of each compment in the blend, however, cannot be readily determined from the chart bscause tho percentages given onthe altitudes of the trlanglc show only the anounts of the binary blends at the vertexes. For this reason, the grid of the chart was so adjusted, as shown in figure ll(b) I that the quantity of any one of the four corqonents in the blend could bo read directly from the chart. The concentration of isopeutane in the blends is shown by the red lines. As an example of the method of detemining the composition.offuel in figure ll(b) suppose that it Ps desired to prepare a blend of triptane, aviation alkylate, virgin base stock, and isopentane having a lean-rich rating of 130/18O, The concentrations of triptane, alkylate, and virgin base stock in the blend having the desired rating csn be read directly from the altltudas of the triangle in the manner used in previous charts. These concentrations are 48, 19, and 13 percent, resgectivuly. The concentration of isopentane can be determined either by subtracting the sum of the percentages of the other componunts from 100 or by noting the position of the blend on the chart relative to the red line (20 percent isopentane). ri d Performance charts for the following quaternary systems have been prepared and are presented in figure 12. Triptane - hot-acid octane - aviation alkylate - isopentane Triptane - diisopropyl - aviation alkylate - isopentane Triptane - diisopropyl - hot-acid octane -- isopentane Diisopropyl - hot-acid octane - aviutioa alkylate - isopentane The vapor pressure determined for the diisopropyl used in figure 12 was 7.4 pounds per square inch. (Ste table 11.) In the preparation of figure 12, however, a vapor pressure of 7 pounds per square inch was assumed for diisopropyl. ACCURACY OF PERFORMANCE CHARTS The accuracy of the charts was determined by selecting ternary or quaternary blends from the various charts and testing these blends by the standard F-3 and 2'-4 procedures. Inasmuch as the 8

10 I NACA I'vlR No. E5A29 - B I F-4 ratinds shom on the chrts were estimated at 8 fnel-air ratio of 0-11, the check ratings were detwmined atithis same fuel-air ratio. The clieck blends tested ere shown with tht?ir ratings in table 111. These blends am also shown on the various charts by the s*pboi.s. The fuel num5ers shown ad,jacent to each of the symbols on t'ne charts correspond to the fuel nunbers given in this table. All the data in table 111 are presented. in f-igure 13 to show the relation between estimatcd and observed pel-fomance nmbers. For the 25 blends shotcm in figure 13 the avmage deviation from the match line was 3.1 performnncf~: numbers for the F-3 ratings and 1.5 for the F-4 ratings. 1 In consideration of tho accurricy of the charts it mdst be emphasized that the prcvious3.y mentioned discr3panciss noted in the F-3 ratings of binary blsnds containing aromatics are responsible for sone of the large deviations in tab For this rmson the F-3 performance lines for tsc aranatic eystems ahom in figmes 7 and 8 must be used with considerabl.6 caution. I 'B DISCUSSIO3? OF?ERFOBU..NCE CHARTS I The data in figures 7 and 8 can'be used for certain general comparisono of p..zraffins, arouiatics, and ethers. In figure 7(a) Tor exauple, at, the point representing a blend of 80 percent aviation alkylate, 20 percent virgh base stock, and 4 ml YET, per gallon the lean-rich rating is 110/i22. Moving on a straight line from this point toward the triptane vertex until 2c) percent triptane bas been added, the rating becoaes l18/14!5. The addition of 20 percent triptane to the base blenc? has thus increased the lean rating of the base blend by 8 performance num5ers and the rich Pating by 25. On the other hand, if in figure 7(e) 20 percent benzene is added to the saae base blend used in the foregoing example, then the rating changes from 110/122 to 106/146. The addition of 2'3 percent benzene has decreasei the lean rating by 4 performnce numbers-, wkereas the rich rating has been increased by 24. From this comparison it follows that in the illustrative example the aromatic (benzene) and the garaffin (triptane) are equally effective for increasing the F 4 (rich) performance but that triptane is more effective than benzene for iqroving lean performance..

11 8. 10 NACA MR No. E5A29 When any two of the charts in figure 7 or 8 aye compared, 'the nearer a given constant perforinance line is to the base of the triangle, the better the performance of the fuel represelited by the top vertex of the triangle. For example, in figure 7(a) the line representing an F-4 performance nuinber of' 200 is xuch nearer the base of the triangle than the same line in figure 7(b). Triptane plus 4 ml YET, per gallon has therefore a higher rating than diiso-, propyl plus 4 ml TEL per gallon. Observations similar to those made in the foregoing discussion can be made for the charts in figures 11 and 12. In the case of these figures, however, the effect of a single component cannot be isolated from the other components because the concentration of isopentane varies with that of any other component in the system. SUMMARY OF Charts are presented which permit the estimatlon of F-3 and F-4 knock-1.imited pex+f' ormance ratings for certain ternary and quaternary fuel blends.' Ratings for various ternary and quaternary blends estimated from these charts com9ax-e favorably with experimental F-3 and F-4 ratings. Because of the unusual behavior of some of the aromatic blends in the F-3 engine, the charts for aromaticparaffinic blends are probably less accurate than, the charts for purely paraffinic blends.! 4 Aircraft Engine Research Laboratory, National Advisory Committee for Aeronautics, Cleveland, Ohio, January 29, 1944.,. I

12 NACA MR Bo. E5A23 11 APPRI'JDXX - THE USE CF TRTKNC*UL:G COORDINATE PAPFR TLe use of triangular coorhinztz paper to represent cmpositim f3r 8 throe-cmponent system will be greatly sjmplified if it is rexembersd that f x any pint ir, an equilateral triangle the stun of tht? perpendicukrs frmi tkat point to esch of the sides is equal to the IzltittCie of th2 trianklc. Fcy example, in the followifig diagrm OP t OPJ = Bb. R, b Y If each of the vertexes of tho triangle rcpresent 100 $ercent of one of the? tkiiee constitxnts, then the percentage: of compment in lolecd 0 is 9M; the percentsge of the component B is OP, and thc p;rcont%ge of c3mponent C is OK. A Thc equatim of a straight line 3n trimgvlar coordinate payer is of the fori where a, b, c ccnstajit s 2 = bn1 -t c N ~ i N3 N1, Nzt TJg conccntratisn 9f c~rn~mcnta 1, 2? end 3 LE ternary Blend Any equatim relstting kncck-liaitzd perforaxme and blend carnpsiti~n that can be redace& ts thjs form cxl he reprepented by a straight

13 12 NACA MR No. E5A29 * line of constant perfr;m,ance on triangvlar coordinate paper. Equation (1) presented in the text of this report can be reduced to thi8 form by multiplying through by any one of the performance values p1, P2 or f?3* t -. / RQERENCES 1. Imrring, Harry S, Barnett, Henry C., and Genco, Russell S.: F-3 and F-4 Engine Tests of Several High-Antiknock CoraFonents of Aviation Fuel. NACA MR No. E4K27, Sanders, Newell D.: A Method of Estimating the Knock Rating of Bydrocarbon FvLel Blonds. NACA ARR TJo. 5321, Sherwood, Thomas K., and Reed, Charles E.: Applied Mathematics in Chemical Engineering McGraw-Hill Book Co., Inc., 1939, pp Sanders, Bewell D., Hensley, Reece V., and Breitvioser, Roland: Experimental Studies of the Knock-Limited Blending Characteristics of Aviation Fuels. I -* Preliminary Tests in an Air- Cooled Cylinder. PTACA ARR No. E4128, Sanders, Newell I>, Wear, Jerrold D., and Stricker, Edward G.: Knock-Limited Blending Characteristics of Fuel Com2onents in a Pratt & Whitney R-2800 Cylinder. I - Triptane, Hot-Acid Octanes, Isopentane Diisopropyl, Neohex.ane, and Xylidines (Avahible TTACA MR No. E4JO1, Axmy Air Forces, Oct. 1, as NACA TN fijo. 1374, 1947.)

14 WACA MR IlOe E5A29 13 h Fuel Fuel compositiona F-3 [by ~olume] ratings F-4 rating& Fuel-air ratio A-355 VBS A-118 SO$ alkylate + 50% VUS _---_ A-356 Alkylate A % one-pass stock + 70% VSS -_ A $ one-pass stock + 50% VBS I A % one-pass stock + ZC$ VBS A $ one-pass stock alkylate -_ A-117 5@$ one-pass stock c 50$ alkylate _-_--_ io A-121 SO$ one-pass stock + 20% alkylate A-410 A-136 One-pass stock triptane f 8& VRS - - -, I ) %aeh fuel contains approximately 4 ml TEL/ al. bbased on a fixed reference-fuel framework?reference 1). NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

15 14. WACA MR NO* E5A29 TABLE I - PERFOXWLNCE RATINGS ORTAINED IN F-3 AND P-4 ENGINES - Contlnued A-277 A-278 A-279 A A-398 A-389 A-400 A-405 A-406 A-407 A-40E A-401 A-402 A-40: -- A- 04 A-39:?.cvk trlptane + BO$ one-pass stock' e 96 30% triptane t 20% one-pass stock' --: e rri pt ane Fuel compos it i ona [by vol urnj 50% triptane + 4C$ one-pass stock' 20% diisopropyl + 80% *JES 40% dilsopropy: + 60$ VNS SO$ dlisopropyl + 40% VBS 80% dilsopropyl + 20% VBS 20% dllsopropyl + 8@ alkylate 40% diisopropyl + 60$ alkylate 20% diisopropyl + 8& one-pas8 Stock: _ Y % dllsopropyl + 60% one-pass stock EO$ dilsopropyl + 40$ one-pass stock I 0.24 aeach fuel contalns approxlrncltely 4 rnl?el/gal. bbased on a fixed refcrence-fuel framework (reference 1). I % dilsopropyl + 40% alkylate Dlisopropyl e _ G O iae '5F F-4 ratlnrsb Fue 1 - ai r rat i o ' ::: I ::: _ F If co _ _ le8 21? EO

16 WACA MR NO. E5A29 15 TABLE 1 - PERFORMANCE RATINGS OBTAINED IN F-S AND F-4 ENGINES - Continued Fuel A-411 A-413 A-414 A-415 A-416 F-4 rating& Fuel compos it iona F Pg. VOI umej ratings vel-air ratio I I @ neohexane + 8C$ VBS O$ neohexane + 60$ VBS O$ neohexana + 40$ VBS neohexane + 20% VRS '@ neohexwe + 8% alkylato % neohexane + 60% alkylate h-417 b A-418 A-420 A-421 A-422 A-423 A-394 A-123 A- 124 A-134 A-375 A-376 A-388 io$ neohexane + ZG$ alkylate ' ?O$ neohexorie + 8@ one-pass stock * kc$ neohexane + E@ one-pass stock SO$ neohexane + 40$ one-p&s.- stock I Oi:: 1 0;;; $ neohexane + 20$ one-pass stock Neohexanef ;% isopentane WS lsopentane f 6O$ MS $ isopentane + 4O$ VBS Q$ isopentane f 8C$ alkylate Q$ isopentane + SO$ alkylate O$ lsopentane + EO$ one-pass stock % isopentane + 60% one-pass stock aeach fuel contains approximately 4 ml TEL/ al. %sed on a fixed reference-fuel framawork $reference 1). NATIONAL ADVISORY COMMITTEE fvalues for knock-limited imep were averaged from two curves. FOR AERONAUTICS

17 16 WACA MR NO* E5A29 TABLE I - PERFORMANCE RATINGS OBTAIBED IN F-3 AND F-4 ENGINES - Continued Fue 1 A- 139 A-140 A- 141 A-367 A A-370 A-371 A-372 A-373 A-374 A-330 Fuel compositiona F- 3 py volume ratings 1?% hot-acid octane t 813$ VBS &@ hot-acld octane t 605 VBS % hot-acld octane t 40$ VDs a@ hot-actd octane + SO$ alkylate C% hot-arid octane +SO$ alkylate % hot-acid octane + 40% alkylate 80% hot-acld octane + 2% alkylate - Of hot-acid octane + 8D$ one-pass stock 4& hot-acid octane + 60% one-pass stock 6C% hot-acid octane + 40$ one-pass stack 8Q% not-azid octane + 20% one-oass stocir Hot-acid octa?ef F-4 ratingab Fuel-air ratio A S _ EO I c A-257 A-258 A-259 A-260 A-261 A-262 A-262 A-264 t aeach fuel contains approximately 4 ml TEL/p,al. bbased on a fixed reference-fuel framework (reference L). fvaluea for knock-limited lmep were averaged from two curves. NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS P

18 NACA MR Hoe E5A29 17 TABLE I - PERFORMANCE RATINGS OBTAINED XN F-3 AND F-4 ENGINES - Continued fie1 Fuel compositiona F-3 - F-4 ratingsb ky volume ratings Fuel-air ratio t A % mixed xylenes one-pass Stock' A % mixed xylenes + 4C$ one-pass stockc A % mixed xylenes + 8& one-pass stock" L A-246 A % cumene + 4% VBs O$ cumrne t Z W ~ VBS A $ cumene t 8096 alkylate A-249 4& cumene + 60$ alkylate A-253 6C$ CUTene + 4C& dlkghte A % cumene i 205 alkylate A : cumene + 80$ one-pass stock _ A $ cumene i SO$ one-pass stwk A $ cumene + 4@ one-pass stock A-255 0% cumene -+ 20$ one-pass stock A-240 Cumenee aeach fuel contains approximately 4 a1 TEL/gal. bbased on a fixed reference-fuel framework (referencs 1). CKnock-limited performance of the engine wlth one-pass catalytic stock was low on the d~y these fuels were tested. evalues for knock-limited inep were averaged from three curves. 88 NATIOHAL ADVISORY COMMITTZ FOR AERONAUTICS

19 18 WACA MR NO. E5A29 TABLE I - F EBWRWCE HATINGS OBTAINED IN E -3 AND F-4 ENGINES - Continued, I-: F-4 ratings Fuel Fuel compositlona F-3 by volctms rot ings Fucl-air ration 3 A ;% benzene +SO$ VBS A % benzene f 6C$ VBS A $ benzene + 4@ VBS l l A $ benzene f 20$ VBS A-358 A % benzene + SO$ alkylate G$% benzene C SO$ alkylate C$ benzene ~40% alkylate % benzene + 20% alkylate C A-362 A-363 A-364 A-365 A-340 2% benzene f 8@ one-pass stock $ benzene + SO$ one-pass stock G % benzene + 4& one-pass stock benzene f 2 6 one-pass stock --_ Benzenef C$ toluene + 80% VBS \ A A-322 A-323 A-324 4% toluene + E& VBS we toluene + 40$ VBS % toluene + 2O$ vas aeach fuel contains approximately 4 ml TEL/gal. bbaaed on a f lxed reference-fuel framerork (reference 1) I fvalues for knock-limited imep Were averaged from two curves. - 0;:; 1 I ;: 1 0;;s: NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

20 NACA MR NO* E TABLE I - PERFORMANCE RATINGS OBTAINED IN F-3 Ada F-4 ENGINES - Concluded %ch fuel contrlns approximately 4 ml TEL/gal. brased on a fixed reference-fuel framework (reference 1). NATIONAL ADVISORY COMMITTEE fvaluas for knock-llmited Imep were averaged from two curves. FOR AERONAUTICS

21 0) -_I_- 20 Blending agent -c_--.i_- Rcid vapor pres sure (YU/SC~ in,) F-3 -IC_- b c Isopeiitarie Ne oh exme lirgin base stock Alkylate Benzew 'k-iptans 10-c -acid octane Toliicne Mixed xylenes Cumene 23.6 G.' '7 1.I-. 3 r-.3 ' " > ' " '7 >2co >20a 19'7 >2@0 >200 :-zoo I ".-.--U ^ a Perfomance numbers am f o pure ~ blending agent conta,in%ng 4 y d ~ ml/gal. bperforn?ance nuibers aver 161 are extrapolated (Pig!. 1). Xatings are for a fuel-ai:- ratio o.f 9*11. CExtrapolated from ex-periciental data for blonds containing ~ip to 60 porcen-t isapentane. dkssmed to be the same as the reting for unleaded benzene. Na t i ond Advi s my Comi t tee for Acr onautic s

22 22 TMT2E TI1 - F-3 AlVD F-4 PEP,FORWCE RRTIlJGS OF TEflBLEY U?D QUA?EBMURY F'XX BLEND3 [TIE fqllowing akbreviations w e used throughout the table: T~%S f~r. virgin 'case stcck; slkylatc fcr aviatlon dkylate; one-pass m?ck,ftr me-iiaso, eatal-yt-i.c stcck; and MTB ether fw raethyl -- ter-t-bi I_!tyl ether.] f> 1.1. i:i 1.2; 12s.i. 5:? ;; triptam + 14% VES + '74y9 alkyl 3. t e "Eadh fuel cmt:;ins approximately TI%/@. '~--4 ratings made at) a fuel-air rati2 of National kdvisory Ccmittee fcr Aermautics.

23 _I_. TABLE TI1 - F-3 AJ!JC F-4 PEWOR?!MTE RATIIJGS OF TEXI'TARY Flybre Fuel I I I I PAW QUATERIVRY F'JEL BLENDS - Ccntinued - Performance numker.9-, Fuel com2asition" (-by vclurns) - -Imated 111 A !50 k-s A * A % k A A lis6 A ^ -- - Nat f cnsl Adv i s x y C c?mi t t ee for iie r onszt i c s

24 L7 112 r- 12 (a) ---r- &vat prnarj- blends ^--

25 NA CA MR NO. E5A29 rl 1 % 0 c X

26 NACA MR No. E5A29 -acid octane and T I ONAL ADVISORY Percentage Composition (by vplumel Figure 2. - Knock-limited performance determined by the F-4 rating method for binary blends of hot-acid octane, an aviation alkylate, and a virgin base stock. All blends contain 4 ml TEL per gallon.

27 NACA MR NO* E5A29

28 NACA MR NO. E5A Percentage composition (by volume) * Figure 4, - Knock-limited performance determined by the F-3 rating method for binary blends of hot-acid octane, an aviation alkylate, and a virgin base stock. All blends contain 4 ml TEL per gallon.

29 NACA MR we. E5A29 rl 6

30 NACA MR No. E5A29

31 NACA MR NO* E5A29!2!2 $5 CC & ch 0 23-M I 1 Eb.

32 NACA MR NO. E5A29 fm 1 1 EE 0 m

33 WACA MR NO. E5A29 w

34 - VI V I- >=I aa OZ VI0 -a >w 06 a a A 0 a& z O W I- w I-I- 6l- Z- 2 I 0 V

35 WACA MR No. E5A29 c - rn V I- >3 KU 02 v)o -a >W oa < a -10 ak z o w -W b-b- Uft- z V

36 NACA MR NO* E5A29 r 4 P

37 HACh MR NO. E5A29 u) V

38 NACA MR NO. E5A29 rl a rl rl d m 4J m 4. a- 1 VIC a4 C+J (uc I40 PO 9 R

39 WACA HR NO. E5A29 rl E f d+ A E 0, X

40 NACA MR NO. E5A29 I I: I O f.rl

41 UACA MR NO. E5A29,

42 NACA MR No. E5A29

43 NACA MR NO* E5A29 el E

44 NACA MR NO. E5A29 r

45 M fm II EE 4

46 HACA MR NO. ESA29 3 I E I

47 NACA MR NO. SA29 z, d 6

48 -1 rl 4-l 0 k 0 0 d c1 2 k d 7 r-i aj 7 Oh m a 4-l c, m

49 NACA MR No. E5A29 c. 14 c fa) Blends with a virgin base stock. Figure 9. - Knock-limited performance of binary blends of cumene with an avlatlon alkylate. a vlrgin base stock, and one-pass catalytlc stock as determined In an F-4 rating engine.

50 WACA WR NO,: ESA1Q e io.xi,a2.13.a4.a5 Fuel-air ratio (b) Blends with an aviation alkylate. Figure 9. - Continued.

51 (r I )r c 0

52

53 . C 0-4 WACA WR NO. E5A29 BB PP ss CC n C c

54 NACA MR NO. E5A29 CI r: d 0 fn 0 I- >I3 ma OZ Cns >w aa a az 20 ak z ow -W ttat t- I 0 % CI s 3 a (d

55 NACA MR NO, E5A29 A

56 NACA MR WO. E5A29 c L

57 NACA MR NO. E5A29. c 4 L P

58 NACA MR NO. E5A29.) 0 k 2 rnh

59 s NATIONAL ADV I SORY COMMITTEE FOR AERONAUTICS 3 w * FY Estimated performance numb r