3180:
838:
2637:
2702:
1405:
637:
68:. Ratios lower than stoichiometric (where the fuel is in excess) are considered "rich". Rich mixtures are less efficient, but may produce more power and burn cooler. Ratios higher than stoichiometric (where the air is in excess) are considered "lean". Lean mixtures are more efficient but may cause higher temperatures, which can lead to the formation of
3175:{\displaystyle {\begin{aligned}\mathrm {Mass\%\ O_{2}\ in\ propane\ combustion\ gas} &\approx -0.1433(\mathrm {\%\ excess\ O_{2}} )^{2}+0.214(\mathrm {\%\ excess\ O_{2}} )\\\mathrm {Volume\%\ O_{2}\ in\ propane\ combustion\ gas} &\approx -0.1208(\mathrm {\%\ excess\ O_{2}} )^{2}+0.186(\mathrm {\%\ excess\ O_{2}} )\end{aligned}}}
1539:
46:),The air–fuel ratio determines whether a mixture is combustible at all, how much energy is being released, and how much unwanted pollutants are produced in the reaction. Typically a range of fuel to air ratios exists, outside of which ignition will not occur. These are known as the lower and upper explosive limits.
1212:
833:{\displaystyle \phi ={\frac {\mbox{fuel-to-oxidizer ratio}}{({\mbox{fuel-to-oxidizer ratio}})_{\text{st}}}}={\frac {m_{\text{fuel}}/m_{\text{ox}}}{\left(m_{\text{fuel}}/m_{\text{ox}}\right)_{\text{st}}}}={\frac {n_{\text{fuel}}/n_{\text{ox}}}{\left(n_{\text{fuel}}/n_{\text{ox}}\right)_{\text{st}}}}}
202:
or pinging), specifically a "pre-detonation" event in the context of a spark-ignition engine model. Such detonation can cause serious engine damage as the uncontrolled burning of the fuel-air mix can create very high pressures in the cylinder. As a consequence, stoichiometric mixtures are only used
328:
In the typical air to natural gas combustion burner, a double-cross limit strategy is employed to ensure ratio control. (This method was used in World War II). The strategy involves adding the opposite flow feedback into the limiting control of the respective gas (air or fuel). This assures ratio
307:
or other feedback loops to control fuel to air ratio (lambda control), compensate automatically for this change in the fuel's stoichiometric rate by measuring the exhaust gas composition and controlling fuel volume. Vehicles without such controls (such as most motorcycles until recently, and cars
1934:
Another advantage of using the equivalence ratio is that ratios greater than one always mean there is more fuel in the fuel–oxidizer mixture than required for complete combustion (stoichiometric reaction), irrespective of the fuel and oxidizer being used—while ratios less than one represent a
197:
A perfectly stoichiometric mixture burns very hot and can damage engine components if the engine is placed under high load at this fuel–air mixture. Due to the high temperatures at this mixture, the detonation of the fuel-air mix while approaching or shortly after maximum cylinder pressure is
1734:
1059:
1929:
2255:
2656:, the more common terms are percent excess combustion air and percent stoichiometric air. For example, excess combustion air of 15 percent means that 15 percent more than the required stoichiometric air (or 115 percent of stoichiometric air) is being used.
1411:
171:
In theory, a stoichiometric mixture has just enough air to completely burn the available fuel. In practice, this is never quite achieved, due primarily to the very short time available in an internal combustion engine for each combustion cycle.
355:
of air and the mass of fuel in the fuel–air mix at any given moment. The mass is the mass of all constituents that compose the fuel and air, whether combustible or not. For example, a calculation of the mass of natural gas—which often contains
854:
The advantage of using equivalence ratio over fuel–oxidizer ratio is that it takes into account (and is therefore independent of) both mass and molar values for the fuel and the oxidizer. Consider, for example, a mixture of one mole of
1167:
Clearly the two values are not equal. To compare it with the equivalence ratio, we need to determine the fuel–oxidizer ratio of ethane and oxygen mixture. For this we need to consider the stoichiometric reaction of ethane and oxygen,
1400:{\displaystyle ({\text{fuel-to-oxidizer ratio based on mass}})_{\text{st}}=\left({\frac {m_{{\ce {C2H6}}}}{m_{{\ce {O2}}}}}\right)_{\text{st}}={\frac {1\times (2\times 12+6\times 1)}{3.5\times (2\times 16)}}={\frac {30}{112}}=0.268}
299:. These compounds all alter the stoichiometric ratio, with most of the additives pushing the ratio downward (oxygenators bring extra oxygen to the combustion event in liquid form that is released at the time of combustions; for
2548:
599:
2626:
127:
The original narrow-band oxygen sensors became factory installed standard in the late 1970s and early 1980s. In recent years a newer and much more accurate wide-band sensor, though more expensive, has become available.
1162:
1550:
902:
2137:
1745:
182:(100 revolutions per second, or 10 milliseconds per revolution of the crankshaft. For a four-stroke engine this would mean 5 milliseconds for each piston stroke, and 20 milliseconds to complete one 720 degree
489:
2707:
203:
under light to low-moderate load conditions. For acceleration and high-load conditions, a richer mixture (lower air–fuel ratio) is used to produce cooler combustion products (thereby utilizing
3298:
53:
or industrial furnace, the air–fuel ratio is an important measure for anti-pollution and performance-tuning reasons. If exactly enough air is provided to completely burn all of the fuel (
1972:
2465:
1534:{\displaystyle ({\text{fuel-to-oxidizer ratio based on number of moles}})_{\text{st}}=\left({\frac {n_{{\ce {C2H6}}}}{n_{{\ce {O2}}}}}\right)_{\text{st}}={\frac {1}{3.5}}=0.286}
1935:
deficiency of fuel or equivalently excess oxidizer in the mixture. This is not the case if one uses fuel–oxidizer ratio, which takes different values for different mixtures.
2125:
604:
Because the composition of common fuels varies seasonally, and because many modern vehicles can handle different fuels when tuning, it makes more sense to talk about
186:). This is the time that elapses from the spark plug firing until 90% of the fuel–air mix is combusted, typically some 80 degrees of crankshaft rotation later.
611:
Most practical AFR devices actually measure the amount of residual oxygen (for lean mixes) or unburnt hydrocarbons (for rich mixtures) in the exhaust gas.
420:
The air-fuel ratio of 12:1 is considered as the maximum output ratio, whereas the air-fuel ratio of 16:1 is considered as the maximum fuel economy ratio.
2484:
548:
2560:
1729:{\displaystyle \phi ={\frac {m_{{\ce {C2H6}}}/m_{{\ce {O2}}}}{\left(m_{{\ce {C2H6}}}/m_{{\ce {O2}}}\right)_{\text{st}}}}={\frac {0.938}{0.268}}=3.5}
308:
predating the mid-1980s) may have difficulties running certain fuel blends (especially winter fuels used in some areas) and may require different
2667:
may be used to measure the percent oxygen in the combustion gas, from which the percent excess oxygen can be calculated from stoichiometry and a
1054:{\displaystyle {\frac {m_{{\ce {C2H6}}}}{m_{{\ce {O2}}}}}={\frac {1\times (2\times 12+6\times 1)}{1\times (2\times 16)}}={\frac {30}{32}}=0.9375}
1924:{\displaystyle \phi ={\frac {n_{{\ce {C2H6}}}/n_{{\ce {O2}}}}{\left(n_{{\ce {C2H6}}}/n_{{\ce {O2}}}\right)_{\text{st}}}}={\frac {1}{0.286}}=3.5}
1070:
3492:
2250:{\displaystyle s=\mathrm {AFR} _{\mathrm {stoich} }={\frac {W_{\mathrm {O} }\times v_{\mathrm {O} }}{W_{\mathrm {F} }\times v_{\mathrm {F} }}}}
3450:
3393:
163: in) diameters, as other types of car 'gauges'. These usually have 10 or 20 LEDs. Analogue 'needle' style gauges are also available.
631:(phi), of a system is defined as the ratio of the fuel-to-oxidizer ratio to the stoichiometric fuel-to-oxidizer ratio. Mathematically,
3443:
3281:
3249:
227:
fuel, the stoichiometric air–fuel mixture is about 14.7:1 i.e. for every one gram of fuel, 14.7 grams of air are required. For pure
445:
3267:
413:
In naturally aspirated engines powered by octane, maximum power is frequently reached at AFRs ranging from 12.5 to 13.3:1 or
348:
is the predominant word that appears in training texts, operation manuals, and maintenance manuals in the aviation world.
538:
from an AFR, divide AFR by the stoichiometric AFR for that fuel. This last equation is often used as the definition of
3487:
3482:
3191:
135:
and some have more. Also common, narrow band meters in round housings with the standard mounting 52 and 67 mm (
436:
101:
50:
39:
1944:
3201:
2664:
337:
There are other terms commonly used when discussing the mixture of air and fuel in internal combustion engines.
317:
2308:
1938:
The fuel–air equivalence ratio is related to the air–fuel equivalence ratio (defined previously) as follows:
284:
223:
mixture for a gasoline engine is the ideal ratio of air to fuel that burns all fuel with no excess air. For
3345:
3241:
2302:
are the fuel and oxygen stoichiometric coefficients, respectively. The stoichiometric mixture fraction is
178:
3370:
3273:
3458:
132:
204:
187:
2659:
A combustion control point can be defined by specifying the percent excess air (or oxygen) in the
175:
Most of the combustion process is completed in approximately 2 milliseconds at an engine speed of
2645:
3404:
392:—includes the mass of the carbon dioxide, nitrogen and all alkanes in determining the value of
3277:
3245:
2696:
between 15.58 and 20.3), the relationship between percent excess air and percent oxygen is:
1998:
3497:
3351:. U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy. November 2007
3313:
3206:
1989:
1983:
1064:
and the fuel-oxidizer ratio of this mixture based on the number of moles of fuel and air is
3299:"Soot inception limits in laminar diffusion flames with application to oxy-fuel combustion"
2660:
279:). In reality, most fuels consist of a combination of heptane, octane, a handful of other
199:
3437:
3317:
357:
220:
81:
69:
55:
43:
3476:
3216:
1988:
The relative amounts of oxygen enrichment and fuel dilution can be quantified by the
313:
312:
jets (or otherwise have the fueling ratios altered) to compensate. Vehicles that use
304:
208:
117:
3433:
2668:
2636:
303:-laden fuel, a stoichiometric ratio can be as low as 14.1:1). Vehicles that use an
3330:
84:
due to different altitude or intake air temperature, possible dilution by ambient
2543:{\displaystyle Z_{\text{st}}={\frac {\lambda }{1+\lambda }}={\frac {1}{1+\phi }}}
851:
represents a number of moles, subscript st stands for stoichiometric conditions.
594:{\displaystyle \lambda ={\frac {\mathrm {AFR} }{\mathrm {AFR} _{\text{stoich}}}}}
2653:
2649:
896:). The fuel–oxidizer ratio of this mixture based on the mass of fuel and air is
432:
191:
85:
2621:{\displaystyle \mathrm {AFR} ={\frac {Y_{\mathrm {O,0} }}{Y_{\mathrm {F,0} }}}}
3332:
Introduction to Fuel and Energy: 1) MOLES, MASS, CONCENTRATION AND DEFINITIONS
3211:
3196:
309:
283:, plus additives including detergents, and possibly oxygenators such as MTBE (
276:
183:
35:
38:
process. The combustion may take place in a controlled manner such as in an
264:
260:
73:
1157:{\displaystyle {\frac {n_{{\ce {C2H6}}}}{n_{{\ce {O2}}}}}={\frac {1}{1}}=1}
507:(lambda), is the ratio of actual AFR to stoichiometry for a given mixture.
3401:
Mechanical and
Aerospace Engineering 406 - Energy Conservation in Industry
373:
296:
224:
389:
292:
280:
272:
881:
856:
403:
228:
77:
2663:, or by specifying the percent oxygen in the combustion product. An
1544:
Thus we can determine the equivalence ratio of the given mixture as
534:
by the stoichiometric AFR for that fuel. Alternatively, to recover
267:– given perfect (ideal) "test" fuel (gasoline consisting of solely
80:
content of combustion air should be specified because of different
2692:) combustion between stoichiometric and 30 percent excess air (AFR
2635:
194:
passing through them are the result of nearly perfect combustion.
3346:"Energy Tips – Process Heating – Check Burner Air to Fuel Ratios"
300:
31:
42:
or industrial furnace, or may result in an explosion (e.g., a
27:
2274:
represent the fuel and oxidizer mass fractions at the inlet,
3236:
Hillier, V.A.W.; Pittuck, F.W. (1966). "Sub-section 3.2".
484:{\displaystyle \mathrm {FAR} ={\frac {1}{\mathrm {AFR} }}}
1883:
1856:
1843:
1814:
1787:
1774:
1688:
1661:
1648:
1619:
1592:
1579:
1494:
1472:
1459:
1295:
1273:
1260:
1127:
1105:
1092:
959:
937:
924:
3394:"The Importance of Excess Air in the Combustion Process"
406:
the stoichiometric mixture is approximately 15.1:1, or
659:
649:
2705:
2563:
2487:
2311:
2140:
2001:
1947:
1748:
1553:
1414:
1215:
1073:
905:
640:
551:
448:
511: = 1.0 is at stoichiometry, rich mixtures
72:. Some engines are designed with features to allow
3174:
2620:
2542:
2470:The stoichiometric mixture fraction is related to
2459:
2249:
2119:
1966:
1923:
1728:
1533:
1399:
1156:
1053:
832:
593:
483:
3403:. North Carolina State University. Archived from
3217:Stoichiometric air-to-fuel ratio of common fuels
259:Any mixture greater than 14.7:1 is considered a
2671:for fuel combustion. For example, for propane (
1420:fuel-to-oxidizer ratio based on number of moles
76:. For precise air–fuel ratio calculations, the
439:, and refers to the ratio of fuel to the air.
3371:"Stoichiometric combustion and excess of air"
435:industry as well as in government studies of
8:
3297:Kumfer, B.; Skeen, S.; Axelbaum, R. (2008).
3266:Çengel, Yunus A.; Boles, Michael A. (2006).
131:Most stand-alone narrow-band meters have 10
1967:{\displaystyle \phi ={\frac {1}{\lambda }}}
3158:
3126:
3111:
3100:
3068:
2967:
2938:
2924:
2892:
2877:
2866:
2834:
2733:
2710:
2706:
2704:
2603:
2602:
2585:
2584:
2578:
2564:
2562:
2522:
2501:
2492:
2486:
2440:
2439:
2425:
2424:
2404:
2403:
2390:
2389:
2375:
2374:
2354:
2353:
2346:
2334:
2317:
2316:
2310:
2237:
2236:
2222:
2221:
2208:
2207:
2193:
2192:
2185:
2160:
2159:
2148:
2139:
2097:
2096:
2076:
2075:
2053:
2052:
2038:
2037:
2023:
2022:
2012:
2000:
1954:
1946:
1905:
1894:
1882:
1877:
1872:
1871:
1862:
1855:
1850:
1842:
1837:
1832:
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1793:
1786:
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1773:
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1598:
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1573:
1568:
1567:
1560:
1552:
1515:
1506:
1493:
1488:
1483:
1482:
1471:
1466:
1458:
1453:
1448:
1447:
1441:
1427:
1418:
1413:
1381:
1316:
1307:
1294:
1289:
1284:
1283:
1272:
1267:
1259:
1254:
1249:
1248:
1242:
1228:
1219:
1214:
1138:
1126:
1121:
1116:
1115:
1104:
1099:
1091:
1086:
1081:
1080:
1074:
1072:
1035:
970:
958:
953:
948:
947:
936:
931:
923:
918:
913:
912:
906:
904:
822:
811:
802:
796:
779:
770:
764:
757:
746:
735:
726:
720:
703:
694:
688:
681:
669:
658:
647:
639:
583:
572:
560:
558:
550:
468:
463:
449:
447:
198:possible under high load (referred to as
3238:Fundamentals of Motor Vehicle Technology
351:Air–fuel ratio is the ratio between the
3269:Thermodynamics: An Engineering Approach
3228:
2460:{\displaystyle Z_{\mathrm {st} }=\left}
2288:are the species molecular weights, and
526:and AFR. To calculate AFR from a given
522:There is a direct relationship between
515: < 1.0, and lean mixtures
316:can monitor the air–fuel ratio with an
329:control within an acceptable margin.
88:, or enrichment by oxygen additions.
7:
1221:fuel-to-oxidizer ratio based on mass
207:), and so avoid overheating of the
116:, it reads the voltage output of an
190:are designed to work best when the
3318:10.1016/j.combustflame.2008.03.008
3155:
3148:
3145:
3142:
3139:
3136:
3133:
3127:
3097:
3090:
3087:
3084:
3081:
3078:
3075:
3069:
3048:
3045:
3042:
3036:
3033:
3030:
3027:
3024:
3021:
3018:
3015:
3012:
3009:
3003:
3000:
2997:
2994:
2991:
2988:
2985:
2979:
2976:
2964:
2957:
2954:
2951:
2948:
2945:
2942:
2939:
2921:
2914:
2911:
2908:
2905:
2902:
2899:
2893:
2863:
2856:
2853:
2850:
2847:
2844:
2841:
2835:
2814:
2811:
2808:
2802:
2799:
2796:
2793:
2790:
2787:
2784:
2781:
2778:
2775:
2769:
2766:
2763:
2760:
2757:
2754:
2751:
2745:
2742:
2730:
2723:
2720:
2717:
2714:
2711:
2604:
2586:
2571:
2568:
2565:
2441:
2426:
2405:
2391:
2376:
2355:
2321:
2318:
2238:
2223:
2209:
2194:
2176:
2173:
2170:
2167:
2164:
2161:
2155:
2152:
2149:
2098:
2077:
2054:
2039:
2024:
579:
576:
573:
567:
564:
561:
475:
472:
469:
456:
453:
450:
100:monitors the air–fuel ratio of an
14:
231:fuel, the oxidation reaction is:
3457:(February 2002). Archived from
3455:Aircraft Maintenance Technology
3451:"Mixed Up About Fuel Mixtures?"
211:, and thus prevent detonation.
30:to a solid, liquid, or gaseous
3165:
3123:
3108:
3065:
2931:
2889:
2874:
2831:
1424:
1415:
1372:
1360:
1349:
1325:
1225:
1216:
1026:
1014:
1003:
979:
666:
655:
60:), the ratio is known as the
1:
3493:Engine fuel system technology
2632:Percent excess combustion air
2652:steam generators, and large
615:Fuel–air equivalence ratio (
503:Air–fuel equivalence ratio,
495:Air–fuel equivalence ratio (
263:; any less than 14.7:1 is a
3192:Adiabatic flame temperature
167:Internal combustion engines
16:Mass ratio of air to a fuel
3514:
1981:
625:fuel–air equivalence ratio
437:internal combustion engine
102:internal combustion engine
51:internal combustion engine
40:internal combustion engine
3373:. The Engineering ToolBox
215:Engine management systems
3444:Engine Combustion primer
3442:University of Plymouth:
3272:(5th ed.). Boston:
608:values rather than AFR.
530:, multiply the measured
431:is commonly used in the
120:, sometimes also called
2478:(phi) by the equations
2120:{\displaystyle Z=\left}
64:, often abbreviated to
26:) is the mass ratio of
3242:Hutchinson Educational
3176:
2641:
2622:
2544:
2461:
2251:
2121:
1968:
1925:
1730:
1535:
1401:
1158:
1055:
834:
661:fuel-to-oxidizer ratio
651:fuel-to-oxidizer ratio
595:
485:
324:Other types of engines
179:revolutions per minute
62:stoichiometric mixture
3392:Eckerlin, Herbert M.
3335:, accessed 2011-05-25
3177:
2639:
2623:
2545:
2462:
2252:
2122:
1982:Further information:
1969:
1926:
1739:or, equivalently, as
1731:
1536:
1402:
1159:
1056:
847:represents the mass,
835:
596:
519: > 1.0.
486:
424:Fuel–air ratio (FAR)
92:Air-fuel ratio meters
3306:Combustion and Flame
3264:See Example 15.3 in
3202:Air–fuel ratio meter
2703:
2665:air–fuel ratio meter
2561:
2485:
2309:
2138:
1999:
1945:
1746:
1551:
1412:
1213:
1071:
903:
638:
549:
446:
318:air–fuel ratio meter
188:Catalytic converters
106:air–fuel ratio gauge
98:air-fuel ratio meter
3438:catalytic converter
2640:Ideal stoichiometry
1885:
1858:
1845:
1816:
1789:
1776:
1690:
1663:
1650:
1621:
1594:
1581:
1496:
1474:
1461:
1297:
1275:
1262:
1129:
1107:
1094:
961:
939:
926:
417:of 0.850 to 0.901.
205:evaporative cooling
3488:Engineering ratios
3483:Chemical reactions
3172:
3170:
2654:gas-fired turbines
2642:
2618:
2540:
2457:
2247:
2117:
1964:
1921:
1873:
1846:
1833:
1804:
1777:
1764:
1726:
1678:
1651:
1638:
1609:
1582:
1569:
1531:
1484:
1462:
1449:
1397:
1285:
1263:
1250:
1154:
1117:
1095:
1082:
1051:
949:
927:
914:
880:) and one mole of
830:
663:
653:
591:
481:
124:or lambda sensor.
3449:Kamm, Richard W.
3153:
3132:
3095:
3074:
3041:
3008:
2984:
2975:
2962:
2919:
2898:
2861:
2840:
2807:
2774:
2750:
2741:
2728:
2616:
2538:
2517:
2495:
2451:
2448:
2245:
2111:
1962:
1913:
1900:
1897:
1876:
1849:
1836:
1807:
1780:
1767:
1718:
1705:
1702:
1681:
1654:
1641:
1612:
1585:
1572:
1523:
1509:
1500:
1487:
1465:
1452:
1430:
1421:
1389:
1376:
1310:
1301:
1288:
1266:
1253:
1231:
1222:
1146:
1133:
1120:
1098:
1085:
1043:
1030:
965:
952:
930:
917:
828:
825:
814:
799:
782:
767:
752:
749:
738:
723:
706:
691:
676:
672:
662:
652:
589:
586:
479:
410:of 1.00 exactly.
3505:
3469:
3467:
3466:
3420:
3419:
3417:
3415:
3410:on 27 March 2014
3409:
3398:
3389:
3383:
3382:
3380:
3378:
3367:
3361:
3360:
3358:
3356:
3350:
3342:
3336:
3328:
3322:
3321:
3303:
3294:
3288:
3287:
3262:
3256:
3255:
3233:
3207:Mass flow sensor
3181:
3179:
3178:
3173:
3171:
3164:
3163:
3162:
3151:
3130:
3116:
3115:
3106:
3105:
3104:
3093:
3072:
3051:
3039:
3006:
2982:
2973:
2972:
2971:
2960:
2930:
2929:
2928:
2917:
2896:
2882:
2881:
2872:
2871:
2870:
2859:
2838:
2817:
2805:
2772:
2748:
2739:
2738:
2737:
2726:
2691:
2690:
2689:
2681:
2680:
2627:
2625:
2624:
2619:
2617:
2615:
2614:
2613:
2597:
2596:
2595:
2579:
2574:
2549:
2547:
2546:
2541:
2539:
2537:
2523:
2518:
2516:
2502:
2497:
2496:
2493:
2466:
2464:
2463:
2458:
2456:
2452:
2450:
2449:
2447:
2446:
2445:
2444:
2431:
2430:
2429:
2416:
2415:
2414:
2397:
2396:
2395:
2394:
2381:
2380:
2379:
2366:
2365:
2364:
2347:
2335:
2326:
2325:
2324:
2256:
2254:
2253:
2248:
2246:
2244:
2243:
2242:
2241:
2228:
2227:
2226:
2215:
2214:
2213:
2212:
2199:
2198:
2197:
2186:
2181:
2180:
2179:
2158:
2126:
2124:
2123:
2118:
2116:
2112:
2110:
2109:
2108:
2107:
2088:
2087:
2086:
2066:
2065:
2064:
2063:
2044:
2043:
2042:
2029:
2028:
2027:
2013:
1992:, Z, defined as
1990:mixture fraction
1984:Mixture fraction
1978:Mixture fraction
1973:
1971:
1970:
1965:
1963:
1955:
1930:
1928:
1927:
1922:
1914:
1906:
1901:
1899:
1898:
1895:
1893:
1889:
1888:
1887:
1886:
1884:
1881:
1874:
1866:
1861:
1860:
1859:
1857:
1854:
1847:
1844:
1841:
1834:
1820:
1819:
1818:
1817:
1815:
1812:
1805:
1797:
1792:
1791:
1790:
1788:
1785:
1778:
1775:
1772:
1765:
1756:
1735:
1733:
1732:
1727:
1719:
1711:
1706:
1704:
1703:
1700:
1698:
1694:
1693:
1692:
1691:
1689:
1686:
1679:
1671:
1666:
1665:
1664:
1662:
1659:
1652:
1649:
1646:
1639:
1625:
1624:
1623:
1622:
1620:
1617:
1610:
1602:
1597:
1596:
1595:
1593:
1590:
1583:
1580:
1577:
1570:
1561:
1540:
1538:
1537:
1532:
1524:
1516:
1511:
1510:
1507:
1505:
1501:
1499:
1498:
1497:
1495:
1492:
1485:
1477:
1476:
1475:
1473:
1470:
1463:
1460:
1457:
1450:
1442:
1432:
1431:
1428:
1422:
1419:
1406:
1404:
1403:
1398:
1390:
1382:
1377:
1375:
1352:
1317:
1312:
1311:
1308:
1306:
1302:
1300:
1299:
1298:
1296:
1293:
1286:
1278:
1277:
1276:
1274:
1271:
1264:
1261:
1258:
1251:
1243:
1233:
1232:
1229:
1223:
1220:
1189:
1188:
1184:
1163:
1161:
1160:
1155:
1147:
1139:
1134:
1132:
1131:
1130:
1128:
1125:
1118:
1110:
1109:
1108:
1106:
1103:
1096:
1093:
1090:
1083:
1075:
1060:
1058:
1057:
1052:
1044:
1036:
1031:
1029:
1006:
971:
966:
964:
963:
962:
960:
957:
950:
942:
941:
940:
938:
935:
928:
925:
922:
915:
907:
895:
894:
893:
879:
878:
877:
869:
868:
839:
837:
836:
831:
829:
827:
826:
823:
821:
817:
816:
815:
812:
806:
801:
800:
797:
785:
784:
783:
780:
774:
769:
768:
765:
758:
753:
751:
750:
747:
745:
741:
740:
739:
736:
730:
725:
724:
721:
709:
708:
707:
704:
698:
693:
692:
689:
682:
677:
675:
674:
673:
670:
664:
660:
650:
648:
600:
598:
597:
592:
590:
588:
587:
584:
582:
570:
559:
490:
488:
487:
482:
480:
478:
464:
459:
387:
386:
385:
371:
370:
369:
333:Other terms used
181:
162:
161:
157:
154:
148:
147:
143:
140:
3513:
3512:
3508:
3507:
3506:
3504:
3503:
3502:
3473:
3472:
3464:
3462:
3448:
3432:HowStuffWorks:
3429:
3424:
3423:
3413:
3411:
3407:
3396:
3391:
3390:
3386:
3376:
3374:
3369:
3368:
3364:
3354:
3352:
3348:
3344:
3343:
3339:
3329:
3325:
3301:
3296:
3295:
3291:
3284:
3265:
3263:
3259:
3252:
3235:
3234:
3230:
3225:
3188:
3169:
3168:
3154:
3107:
3096:
3052:
2963:
2935:
2934:
2920:
2873:
2862:
2818:
2729:
2701:
2700:
2695:
2688:
2685:
2684:
2683:
2679:
2676:
2675:
2674:
2672:
2634:
2598:
2580:
2559:
2558:
2527:
2506:
2488:
2483:
2482:
2435:
2420:
2399:
2398:
2385:
2370:
2349:
2348:
2339:
2330:
2312:
2307:
2306:
2301:
2294:
2287:
2280:
2273:
2266:
2232:
2217:
2216:
2203:
2188:
2187:
2147:
2136:
2135:
2092:
2071:
2067:
2048:
2033:
2018:
2014:
2008:
1997:
1996:
1986:
1980:
1943:
1942:
1867:
1827:
1826:
1822:
1821:
1798:
1758:
1757:
1744:
1743:
1672:
1632:
1631:
1627:
1626:
1603:
1563:
1562:
1549:
1548:
1478:
1443:
1437:
1436:
1423:
1410:
1409:
1353:
1318:
1279:
1244:
1238:
1237:
1224:
1211:
1210:
1201:
1197:
1193:
1186:
1182:
1181:
1179:
1175:
1111:
1076:
1069:
1068:
1007:
972:
943:
908:
901:
900:
892:
889:
888:
887:
885:
876:
873:
872:
871:
867:
864:
863:
862:
860:
807:
792:
791:
787:
786:
775:
760:
759:
731:
716:
715:
711:
710:
699:
684:
683:
665:
654:
636:
635:
621:
571:
547:
546:
501:
444:
443:
426:
398:
388:), and various
384:
381:
380:
379:
377:
368:
365:
364:
363:
361:
343:
335:
326:
254:
250:
246:
242:
238:
217:
176:
169:
159:
155:
152:
150:
145:
141:
138:
136:
94:
70:nitrogen oxides
17:
12:
11:
5:
3511:
3509:
3501:
3500:
3495:
3490:
3485:
3475:
3474:
3471:
3470:
3446:
3440:
3434:fuel injection
3428:
3427:External links
3425:
3422:
3421:
3384:
3362:
3337:
3323:
3312:(3): 546–556.
3289:
3282:
3257:
3250:
3227:
3226:
3224:
3221:
3220:
3219:
3214:
3209:
3204:
3199:
3194:
3187:
3184:
3183:
3182:
3167:
3161:
3157:
3150:
3147:
3144:
3141:
3138:
3135:
3129:
3125:
3122:
3119:
3114:
3110:
3103:
3099:
3092:
3089:
3086:
3083:
3080:
3077:
3071:
3067:
3064:
3061:
3058:
3055:
3053:
3050:
3047:
3044:
3038:
3035:
3032:
3029:
3026:
3023:
3020:
3017:
3014:
3011:
3005:
3002:
2999:
2996:
2993:
2990:
2987:
2981:
2978:
2970:
2966:
2959:
2956:
2953:
2950:
2947:
2944:
2941:
2937:
2936:
2933:
2927:
2923:
2916:
2913:
2910:
2907:
2904:
2901:
2895:
2891:
2888:
2885:
2880:
2876:
2869:
2865:
2858:
2855:
2852:
2849:
2846:
2843:
2837:
2833:
2830:
2827:
2824:
2821:
2819:
2816:
2813:
2810:
2804:
2801:
2798:
2795:
2792:
2789:
2786:
2783:
2780:
2777:
2771:
2768:
2765:
2762:
2759:
2756:
2753:
2747:
2744:
2736:
2732:
2725:
2722:
2719:
2716:
2713:
2709:
2708:
2693:
2686:
2677:
2644:In industrial
2633:
2630:
2629:
2628:
2612:
2609:
2606:
2601:
2594:
2591:
2588:
2583:
2577:
2573:
2570:
2567:
2552:
2551:
2536:
2533:
2530:
2526:
2521:
2515:
2512:
2509:
2505:
2500:
2491:
2468:
2467:
2455:
2443:
2438:
2434:
2428:
2423:
2419:
2413:
2410:
2407:
2402:
2393:
2388:
2384:
2378:
2373:
2369:
2363:
2360:
2357:
2352:
2345:
2342:
2338:
2333:
2329:
2323:
2320:
2315:
2299:
2292:
2285:
2278:
2271:
2264:
2259:
2258:
2240:
2235:
2231:
2225:
2220:
2211:
2206:
2202:
2196:
2191:
2184:
2178:
2175:
2172:
2169:
2166:
2163:
2157:
2154:
2151:
2146:
2143:
2129:
2128:
2115:
2106:
2103:
2100:
2095:
2091:
2085:
2082:
2079:
2074:
2070:
2062:
2059:
2056:
2051:
2047:
2041:
2036:
2032:
2026:
2021:
2017:
2011:
2007:
2004:
1979:
1976:
1975:
1974:
1961:
1958:
1953:
1950:
1932:
1931:
1920:
1917:
1912:
1909:
1904:
1892:
1880:
1870:
1865:
1853:
1840:
1830:
1825:
1811:
1801:
1796:
1784:
1771:
1761:
1754:
1751:
1737:
1736:
1725:
1722:
1717:
1714:
1709:
1697:
1685:
1675:
1670:
1658:
1645:
1635:
1630:
1616:
1606:
1601:
1589:
1576:
1566:
1559:
1556:
1542:
1541:
1530:
1527:
1522:
1519:
1514:
1504:
1491:
1481:
1469:
1456:
1446:
1440:
1435:
1426:
1417:
1407:
1396:
1393:
1388:
1385:
1380:
1374:
1371:
1368:
1365:
1362:
1359:
1356:
1351:
1348:
1345:
1342:
1339:
1336:
1333:
1330:
1327:
1324:
1321:
1315:
1305:
1292:
1282:
1270:
1257:
1247:
1241:
1236:
1227:
1218:
1204:
1203:
1199:
1195:
1191:
1177:
1173:
1165:
1164:
1153:
1150:
1145:
1142:
1137:
1124:
1114:
1102:
1089:
1079:
1062:
1061:
1050:
1047:
1042:
1039:
1034:
1028:
1025:
1022:
1019:
1016:
1013:
1010:
1005:
1002:
999:
996:
993:
990:
987:
984:
981:
978:
975:
969:
956:
946:
934:
921:
911:
890:
874:
865:
841:
840:
820:
810:
805:
795:
790:
778:
773:
763:
756:
744:
734:
729:
719:
714:
702:
697:
687:
680:
668:
657:
646:
643:
620:
613:
602:
601:
581:
578:
575:
569:
566:
563:
557:
554:
500:
493:
492:
491:
477:
474:
471:
467:
462:
458:
455:
452:
429:Fuel–air ratio
425:
422:
396:
382:
366:
358:carbon dioxide
342:
339:
334:
331:
325:
322:
314:oxygen sensors
257:
256:
252:
248:
244:
240:
236:
221:stoichiometric
216:
213:
168:
165:
114:air–fuel gauge
110:air–fuel meter
104:. Also called
93:
90:
56:stoichiometric
44:dust explosion
20:Air–fuel ratio
15:
13:
10:
9:
6:
4:
3:
2:
3510:
3499:
3496:
3494:
3491:
3489:
3486:
3484:
3481:
3480:
3478:
3461:on 2010-11-20
3460:
3456:
3452:
3447:
3445:
3441:
3439:
3435:
3431:
3430:
3426:
3406:
3402:
3395:
3388:
3385:
3372:
3366:
3363:
3347:
3341:
3338:
3334:
3333:
3327:
3324:
3319:
3315:
3311:
3307:
3300:
3293:
3290:
3285:
3283:9780072884951
3279:
3275:
3271:
3270:
3261:
3258:
3253:
3251:0-09-110711-3
3247:
3243:
3239:
3232:
3229:
3222:
3218:
3215:
3213:
3210:
3208:
3205:
3203:
3200:
3198:
3195:
3193:
3190:
3189:
3185:
3159:
3120:
3117:
3112:
3101:
3062:
3059:
3056:
3054:
2968:
2925:
2886:
2883:
2878:
2867:
2828:
2825:
2822:
2820:
2734:
2699:
2698:
2697:
2670:
2666:
2662:
2657:
2655:
2651:
2647:
2646:fired heaters
2638:
2631:
2610:
2607:
2599:
2592:
2589:
2581:
2575:
2557:
2556:
2555:
2534:
2531:
2528:
2524:
2519:
2513:
2510:
2507:
2503:
2498:
2489:
2481:
2480:
2479:
2477:
2474:(lambda) and
2473:
2453:
2436:
2432:
2421:
2417:
2411:
2408:
2400:
2386:
2382:
2371:
2367:
2361:
2358:
2350:
2343:
2340:
2336:
2331:
2327:
2313:
2305:
2304:
2303:
2298:
2291:
2284:
2277:
2270:
2263:
2233:
2229:
2218:
2204:
2200:
2189:
2182:
2144:
2141:
2134:
2133:
2132:
2113:
2104:
2101:
2093:
2089:
2083:
2080:
2072:
2068:
2060:
2057:
2049:
2045:
2034:
2030:
2019:
2015:
2009:
2005:
2002:
1995:
1994:
1993:
1991:
1985:
1977:
1959:
1956:
1951:
1948:
1941:
1940:
1939:
1936:
1918:
1915:
1910:
1907:
1902:
1890:
1878:
1868:
1863:
1851:
1838:
1828:
1823:
1809:
1799:
1794:
1782:
1769:
1759:
1752:
1749:
1742:
1741:
1740:
1723:
1720:
1715:
1712:
1707:
1695:
1683:
1673:
1668:
1656:
1643:
1633:
1628:
1614:
1604:
1599:
1587:
1574:
1564:
1557:
1554:
1547:
1546:
1545:
1528:
1525:
1520:
1517:
1512:
1502:
1489:
1479:
1467:
1454:
1444:
1438:
1433:
1408:
1394:
1391:
1386:
1383:
1378:
1369:
1366:
1363:
1357:
1354:
1346:
1343:
1340:
1337:
1334:
1331:
1328:
1322:
1319:
1313:
1303:
1290:
1280:
1268:
1255:
1245:
1239:
1234:
1209:
1208:
1207:
1171:
1170:
1169:
1151:
1148:
1143:
1140:
1135:
1122:
1112:
1100:
1087:
1077:
1067:
1066:
1065:
1048:
1045:
1040:
1037:
1032:
1023:
1020:
1017:
1011:
1008:
1000:
997:
994:
991:
988:
985:
982:
976:
973:
967:
954:
944:
932:
919:
909:
899:
898:
897:
883:
858:
852:
850:
846:
818:
808:
803:
793:
788:
776:
771:
761:
754:
742:
732:
727:
717:
712:
700:
695:
685:
678:
644:
641:
634:
633:
632:
630:
626:
618:
614:
612:
609:
607:
555:
552:
545:
544:
543:
541:
537:
533:
529:
525:
520:
518:
514:
510:
506:
498:
494:
465:
460:
442:
441:
440:
438:
434:
430:
423:
421:
418:
416:
411:
409:
405:
400:
395:
391:
375:
359:
354:
349:
347:
340:
338:
332:
330:
323:
321:
319:
315:
311:
306:
305:oxygen sensor
302:
298:
294:
290:
288:
282:
278:
274:
270:
266:
262:
234:
233:
232:
230:
226:
222:
214:
212:
210:
209:cylinder head
206:
201:
195:
193:
192:exhaust gases
189:
185:
180:
173:
166:
164:
134:
129:
125:
123:
119:
118:oxygen sensor
115:
111:
107:
103:
99:
91:
89:
87:
83:
79:
75:
71:
67:
63:
59:
57:
52:
47:
45:
41:
37:
34:present in a
33:
29:
25:
21:
3463:. Retrieved
3459:the original
3454:
3412:. Retrieved
3405:the original
3400:
3387:
3375:. Retrieved
3365:
3353:. Retrieved
3340:
3331:
3326:
3309:
3305:
3292:
3268:
3260:
3237:
3231:
2669:mass balance
2658:
2643:
2553:
2475:
2471:
2469:
2296:
2289:
2282:
2275:
2268:
2261:
2260:
2130:
1987:
1937:
1933:
1738:
1543:
1205:
1166:
1063:
853:
848:
844:
842:
628:
624:
622:
616:
610:
605:
603:
539:
535:
531:
527:
523:
521:
516:
512:
508:
504:
502:
496:
428:
427:
419:
414:
412:
407:
401:
393:
352:
350:
345:
344:
336:
327:
289:-butyl ether
286:
268:
265:rich mixture
261:lean mixture
258:
247:→ 16 CO
218:
196:
174:
170:
130:
126:
121:
113:
109:
105:
97:
95:
65:
61:
54:
48:
23:
19:
18:
3274:McGraw-Hill
2650:power plant
1206:This gives
1194:→ 2 CO
433:gas turbine
251:+ 18 H
177:6,000
86:water vapor
82:air density
3477:Categories
3465:2009-03-18
3240:. London:
3223:References
3212:Combustion
3197:AFR sensor
1198:+ 3 H
310:carburetor
277:iso-octane
255:O + energy
239:+ 2 C
184:Otto cycle
122:AFR sensor
58:combustion
36:combustion
3128:%
3070:%
3060:−
3057:≈
2958:%
2894:%
2836:%
2826:−
2823:≈
2724:%
2554:assuming
2535:ϕ
2514:λ
2504:λ
2433:×
2418:×
2383:×
2368:×
2230:×
2201:×
2031:−
1960:λ
1949:ϕ
1750:ϕ
1555:ϕ
1367:×
1358:×
1344:×
1332:×
1323:×
1021:×
1012:×
998:×
986:×
977:×
642:ϕ
553:λ
402:For pure
235:25 O
74:lean-burn
3186:See also
374:nitrogen
297:methanol
225:gasoline
200:knocking
3498:Engines
3414:29 July
3377:29 July
3355:29 July
2661:oxidant
1190: O
1185:⁄
390:alkanes
346:Mixture
341:Mixture
293:ethanol
285:methyl
281:alkanes
273:heptane
158:⁄
144:⁄
3280:
3248:
3152:
3131:
3094:
3073:
3063:0.1208
3040:
3007:
2983:
2974:
2961:
2918:
2897:
2860:
2839:
2829:0.1433
2806:
2773:
2749:
2740:
2727:
2131:where
1049:0.9375
882:oxygen
857:ethane
843:where
585:stoich
404:octane
229:octane
78:oxygen
66:stoich
49:In an
3408:(PDF)
3397:(PDF)
3349:(PDF)
3302:(PDF)
3121:0.186
2887:0.214
1911:0.286
1716:0.268
1713:0.938
1529:0.286
1395:0.268
291:) or
112:, or
3416:2013
3379:2013
3357:2013
3278:ISBN
3246:ISBN
2694:mass
2295:and
2281:and
2267:and
798:fuel
766:fuel
722:fuel
690:fuel
623:The
397:fuel
353:mass
301:MTBE
287:tert
275:and
219:The
149:and
133:LEDs
32:fuel
3314:doi
3310:154
2272:O,0
2265:F,0
1919:3.5
1724:3.5
1521:3.5
1387:112
1355:3.5
372:),
96:An
28:air
24:AFR
3479::
3453:.
3436:,
3399:.
3308:.
3304:.
3276:.
3244:.
2648:,
2494:st
1896:st
1701:st
1508:st
1429:st
1384:30
1370:16
1335:12
1309:st
1230:st
1180:+
1041:32
1038:30
1024:16
989:12
824:st
813:ox
781:ox
748:st
737:ox
705:ox
671:st
627:,
542::
399:.
362:CO
320:.
245:18
146:16
108:,
3468:.
3418:.
3381:.
3359:.
3320:.
3316::
3286:.
3254:.
3166:)
3160:2
3156:O
3149:s
3146:s
3143:e
3140:c
3137:x
3134:e
3124:(
3118:+
3113:2
3109:)
3102:2
3098:O
3091:s
3088:s
3085:e
3082:c
3079:x
3076:e
3066:(
3049:s
3046:a
3043:g
3037:n
3034:o
3031:i
3028:t
3025:s
3022:u
3019:b
3016:m
3013:o
3010:c
3004:e
3001:n
2998:a
2995:p
2992:o
2989:r
2986:p
2980:n
2977:i
2969:2
2965:O
2955:e
2952:m
2949:u
2946:l
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2940:V
2932:)
2926:2
2922:O
2915:s
2912:s
2909:e
2906:c
2903:x
2900:e
2890:(
2884:+
2879:2
2875:)
2868:2
2864:O
2857:s
2854:s
2851:e
2848:c
2845:x
2842:e
2832:(
2815:s
2812:a
2809:g
2803:n
2800:o
2797:i
2794:t
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2788:u
2785:b
2782:m
2779:o
2776:c
2770:e
2767:n
2764:a
2761:p
2758:o
2755:r
2752:p
2746:n
2743:i
2735:2
2731:O
2721:s
2718:s
2715:a
2712:M
2687:8
2682:H
2678:3
2673:C
2611:0
2608:,
2605:F
2600:Y
2593:0
2590:,
2587:O
2582:Y
2576:=
2572:R
2569:F
2566:A
2550:,
2532:+
2529:1
2525:1
2520:=
2511:+
2508:1
2499:=
2490:Z
2476:Φ
2472:λ
2454:]
2442:F
2437:v
2427:F
2422:W
2412:0
2409:,
2406:O
2401:Y
2392:O
2387:v
2377:O
2372:W
2362:0
2359:,
2356:F
2351:Y
2344:+
2341:1
2337:1
2332:[
2328:=
2322:t
2319:s
2314:Z
2300:O
2297:v
2293:F
2290:v
2286:O
2283:W
2279:F
2276:W
2269:Y
2262:Y
2257:,
2239:F
2234:v
2224:F
2219:W
2210:O
2205:v
2195:O
2190:W
2183:=
2177:h
2174:c
2171:i
2168:o
2165:t
2162:s
2156:R
2153:F
2150:A
2145:=
2142:s
2127:,
2114:]
2105:0
2102:,
2099:O
2094:Y
2090:+
2084:0
2081:,
2078:F
2073:Y
2069:s
2061:0
2058:,
2055:O
2050:Y
2046:+
2040:O
2035:Y
2025:F
2020:Y
2016:s
2010:[
2006:=
2003:Z
1957:1
1952:=
1916:=
1908:1
1903:=
1891:)
1879:2
1875:O
1869:n
1864:/
1852:6
1848:H
1839:2
1835:C
1829:n
1824:(
1810:2
1806:O
1800:n
1795:/
1783:6
1779:H
1770:2
1766:C
1760:n
1753:=
1721:=
1708:=
1696:)
1684:2
1680:O
1674:m
1669:/
1657:6
1653:H
1644:2
1640:C
1634:m
1629:(
1615:2
1611:O
1605:m
1600:/
1588:6
1584:H
1575:2
1571:C
1565:m
1558:=
1526:=
1518:1
1513:=
1503:)
1490:2
1486:O
1480:n
1468:6
1464:H
1455:2
1451:C
1445:n
1439:(
1434:=
1425:)
1416:(
1392:=
1379:=
1373:)
1364:2
1361:(
1350:)
1347:1
1341:6
1338:+
1329:2
1326:(
1320:1
1314:=
1304:)
1291:2
1287:O
1281:m
1269:6
1265:H
1256:2
1252:C
1246:m
1240:(
1235:=
1226:)
1217:(
1202:O
1200:2
1196:2
1192:2
1187:2
1183:7
1178:6
1176:H
1174:2
1172:C
1152:1
1149:=
1144:1
1141:1
1136:=
1123:2
1119:O
1113:n
1101:6
1097:H
1088:2
1084:C
1078:n
1046:=
1033:=
1027:)
1018:2
1015:(
1009:1
1004:)
1001:1
995:6
992:+
983:2
980:(
974:1
968:=
955:2
951:O
945:m
933:6
929:H
920:2
916:C
910:m
891:2
886:O
884:(
875:6
870:H
866:2
861:C
859:(
849:n
845:m
819:)
809:n
804:/
794:n
789:(
777:n
772:/
762:n
755:=
743:)
733:m
728:/
718:m
713:(
701:m
696:/
686:m
679:=
667:)
656:(
645:=
629:Φ
619:)
617:Φ
606:λ
580:R
577:F
574:A
568:R
565:F
562:A
556:=
540:λ
536:λ
532:λ
528:λ
524:λ
517:λ
513:λ
509:λ
505:λ
499:)
497:λ
476:R
473:F
470:A
466:1
461:=
457:R
454:A
451:F
415:λ
408:λ
394:m
383:2
378:N
376:(
367:2
360:(
295:/
271:-
269:n
253:2
249:2
243:H
241:8
237:2
160:8
156:5
153:+
151:2
142:1
139:+
137:2
22:(
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