3191:
2648:
849:
2713:
1416:
648:
79:. 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
3186:{\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}}}
1550:
57:),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.
1223:
844:{\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}}}}}
213:
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
339:
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
318:
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
1945:
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
208:
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
1745:
1070:
1940:
2266:
2667:, 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.
1422:
182:
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.
366:
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
865:
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
1178:
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,
1411:{\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}
310:. 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
2559:
610:
2637:
138:
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.
1173:
1561:
913:
2148:
1756:
193:(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
500:
2718:
214:
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
3309:
64:
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 (
1983:
2476:
1545:{\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}
1946:
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.
2136:
615:
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
197:). 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.
622:
Most practical AFR devices actually measure the amount of residual oxygen (for lean mixes) or unburnt hydrocarbons (for rich mixtures) in the exhaust gas.
431:
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.
2495:
559:
2571:
1740:{\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}
319:
predating the mid-1980s) may have difficulties running certain fuel blends (especially winter fuels used in some areas) and may require different
2678:
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
1065:{\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}
1935:{\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}
1081:
2261:{\displaystyle s=\mathrm {AFR} _{\mathrm {stoich} }={\frac {W_{\mathrm {O} }\times v_{\mathrm {O} }}{W_{\mathrm {F} }\times v_{\mathrm {F} }}}}
3461:
3404:
174: in) diameters, as other types of car 'gauges'. These usually have 10 or 20 LEDs. Analogue 'needle' style gauges are also available.
642:(phi), of a system is defined as the ratio of the fuel-to-oxidizer ratio to the stoichiometric fuel-to-oxidizer ratio. Mathematically,
3454:
238:
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
456:
3503:
3227:
3278:
424:
In naturally aspirated engines powered by octane, maximum power is frequently reached at AFRs ranging from 12.5 to 13.3:1 or
359:
is the predominant word that appears in training texts, operation manuals, and maintenance manuals in the aviation world.
549:
from an AFR, divide AFR by the stoichiometric AFR for that fuel. This last equation is often used as the definition of
3292:
3260:
146:
and some have more. Also common, narrow band meters in round housings with the standard mounting 52 and 67 mm (
1955:
348:
There are other terms commonly used when discussing the mixture of air and fuel in internal combustion engines.
17:
2319:
1949:
The fuel–air equivalence ratio is related to the air–fuel equivalence ratio (defined previously) as follows:
234:
mixture for a gasoline engine is the ideal ratio of air to fuel that burns all fuel with no excess air. For
3356:
2313:
are the fuel and oxygen stoichiometric coefficients, respectively. The stoichiometric mixture fraction is
3498:
3493:
3381:
3202:
3469:
447:
112:
61:
50:
3212:
2675:
328:
2670:
A combustion control point can be defined by specifying the percent excess air (or oxygen) in the
186:
Most of the combustion process is completed in approximately 2 milliseconds at an engine speed of
295:
3415:
3252:
403:—includes the mass of the carbon dioxide, nitrogen and all alkanes in determining the value of
189:
3284:
2707:
between 15.58 and 20.3), the relationship between percent excess air and percent oxygen is:
2009:
3362:. U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy. November 2007
1075:
and the fuel-oxidizer ratio of this mixture based on the number of moles of fuel and air is
3310:"Soot inception limits in laminar diffusion flames with application to oxy-fuel combustion"
143:
290:). In reality, most fuels consist of a combination of heptane, octane, a handful of other
8:
215:
198:
3448:
3328:
2656:
3288:
3256:
1999:
The relative amounts of oxygen enrichment and fuel dilution can be quantified by the
323:
jets (or otherwise have the fueling ratios altered) to compensate. Vehicles that use
3508:
3444:
3324:
3217:
2000:
1994:
314:-laden fuel, a stoichiometric ratio can be as low as 14.1:1). Vehicles that use an
3341:
95:
due to different altitude or intake air temperature, possible dilution by ambient
2671:
2554:{\displaystyle Z_{\text{st}}={\frac {\lambda }{1+\lambda }}={\frac {1}{1+\phi }}}
862:
represents a number of moles, subscript st stands for stoichiometric conditions.
605:{\displaystyle \lambda ={\frac {\mathrm {AFR} }{\mathrm {AFR} _{\text{stoich}}}}}
210:
907:). The fuel–oxidizer ratio of this mixture based on the mass of fuel and air is
2632:{\displaystyle \mathrm {AFR} ={\frac {Y_{\mathrm {O,0} }}{Y_{\mathrm {F,0} }}}}
368:
231:
92:
80:
66:
54:
3343:
Introduction to Fuel and Energy: 1) MOLES, MASS, CONCENTRATION AND DEFINITIONS
294:, plus additives including detergents, and possibly oxygenators such as MTBE (
3487:
324:
315:
219:
128:
49:
process. The combustion may take place in a controlled manner such as in an
2679:
1168:{\displaystyle {\frac {n_{{\ce {C2H6}}}}{n_{{\ce {O2}}}}}={\frac {1}{1}}=1}
518:(lambda), is the ratio of actual AFR to stoichiometry for a given mixture.
3412:
Mechanical and
Aerospace Engineering 406 - Energy Conservation in Industry
2664:
2660:
443:
202:
96:
3222:
3207:
320:
287:
194:
46:
2647:
275:
271:
84:
2674:, or by specifying the percent oxygen in the combustion product. An
1555:
Thus we can determine the equivalence ratio of the given mixture as
545:
by the stoichiometric AFR for that fuel. Alternatively, to recover
384:
307:
278:– given perfect (ideal) "test" fuel (gasoline consisting of solely
235:
91:
content of combustion air should be specified because of different
2703:) combustion between stoichiometric and 30 percent excess air (AFR
205:
passing through them are the result of nearly perfect combustion.
3357:"Energy Tips – Process Heating – Check Burner Air to Fuel Ratios"
400:
303:
291:
283:
892:
867:
414:
239:
88:
53:
or industrial furnace, or may result in an explosion (e.g., a
2285:
represent the fuel and oxidizer mass fractions at the inlet,
311:
42:
3247:
Hillier, V.A.W.; Pittuck, F.W. (1966). "Sub-section 3.2".
495:{\displaystyle \mathrm {FAR} ={\frac {1}{\mathrm {AFR} }}}
1894:
1867:
1854:
1825:
1798:
1785:
1699:
1672:
1659:
1630:
1603:
1590:
1505:
1483:
1470:
1306:
1284:
1271:
1138:
1116:
1103:
970:
948:
935:
38:
3405:"The Importance of Excess Air in the Combustion Process"
417:
the stoichiometric mixture is approximately 15.1:1, or
670:
660:
2716:
2574:
2498:
2322:
2151:
2012:
1958:
1759:
1564:
1425:
1226:
1084:
916:
651:
562:
459:
522: = 1.0 is at stoichiometry, rich mixtures
3307:
83:. Some engines are designed with features to allow
3185:
2631:
2553:
2481:The stoichiometric mixture fraction is related to
2470:
2260:
2130:
1977:
1934:
1739:
1544:
1410:
1167:
1064:
843:
604:
494:
3414:. North Carolina State University. Archived from
625:
505:
3485:
3228:Stoichiometric air-to-fuel ratio of common fuels
2642:
270:Any mixture greater than 14.7:1 is considered a
2682:for fuel combustion. For example, for propane (
1431:fuel-to-oxidizer ratio based on number of moles
87:. For precise air–fuel ratio calculations, the
3246:
450:, and refers to the ratio of fuel to the air.
177:
3382:"Stoichiometric combustion and excess of air"
446:industry as well as in government studies of
3308:Kumfer, B.; Skeen, S.; Axelbaum, R. (2008).
3277:Çengel, Yunus A.; Boles, Michael A. (2006).
225:
142:Most stand-alone narrow-band meters have 10
3276:
1978:{\displaystyle \phi ={\frac {1}{\lambda }}}
334:
209:possible under high load (referred to as
3249:Fundamentals of Motor Vehicle Technology
2646:
362:Air–fuel ratio is the ratio between the
102:
3280:Thermodynamics: An Engineering Approach
2471:{\displaystyle Z_{\mathrm {st} }=\left}
2299:are the species molecular weights, and
537:and AFR. To calculate AFR from a given
533:There is a direct relationship between
526: < 1.0, and lean mixtures
434:
327:can monitor the air–fuel ratio with an
14:
3486:
340:control within an acceptable margin.
99:, or enrichment by oxygen additions.
3402:
1232:fuel-to-oxidizer ratio based on mass
218:), and so avoid overheating of the
127:, it reads the voltage output of an
1988:
343:
201:are designed to work best when the
24:
3329:10.1016/j.combustflame.2008.03.008
3166:
3159:
3156:
3153:
3150:
3147:
3144:
3138:
3108:
3101:
3098:
3095:
3092:
3089:
3086:
3080:
3059:
3056:
3053:
3047:
3044:
3041:
3038:
3035:
3032:
3029:
3026:
3023:
3020:
3014:
3011:
3008:
3005:
3002:
2999:
2996:
2990:
2987:
2975:
2968:
2965:
2962:
2959:
2956:
2953:
2950:
2932:
2925:
2922:
2919:
2916:
2913:
2910:
2904:
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2846:
2825:
2822:
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2813:
2810:
2807:
2804:
2801:
2798:
2795:
2792:
2789:
2786:
2780:
2777:
2774:
2771:
2768:
2765:
2762:
2756:
2753:
2741:
2734:
2731:
2728:
2725:
2722:
2615:
2597:
2582:
2579:
2576:
2452:
2437:
2416:
2402:
2387:
2366:
2332:
2329:
2249:
2234:
2220:
2205:
2187:
2184:
2181:
2178:
2175:
2172:
2166:
2163:
2160:
2109:
2088:
2065:
2050:
2035:
590:
587:
584:
578:
575:
572:
486:
483:
480:
467:
464:
461:
111:monitors the air–fuel ratio of an
25:
3520:
3437:
242:fuel, the oxidation reaction is:
3459:
3468:(February 2002). Archived from
3466:Aircraft Maintenance Technology
3462:"Mixed Up About Fuel Mixtures?"
222:, and thus prevent detonation.
41:to a solid, liquid, or gaseous
3396:
3374:
3349:
3335:
3301:
3269:
3240:
3176:
3134:
3119:
3076:
2942:
2900:
2885:
2842:
1435:
1426:
1383:
1371:
1360:
1336:
1236:
1227:
1037:
1025:
1014:
990:
677:
666:
71:), the ratio is known as the
13:
1:
3504:Engine fuel system technology
3233:
2643:Percent excess combustion air
2663:steam generators, and large
626:Fuel–air equivalence ratio (
514:Air–fuel equivalence ratio,
506:Air–fuel equivalence ratio (
274:; any less than 14.7:1 is a
7:
3203:Adiabatic flame temperature
3196:
178:Internal combustion engines
27:Mass ratio of air to a fuel
10:
3525:
1992:
636:fuel–air equivalence ratio
448:internal combustion engine
351:
113:internal combustion engine
62:internal combustion engine
51:internal combustion engine
3384:. The Engineering ToolBox
226:Engine management systems
3455:Engine Combustion primer
3453:University of Plymouth:
3283:(5th ed.). Boston:
619:values rather than AFR.
541:, multiply the measured
442:is commonly used in the
131:, sometimes also called
2489:(phi) by the equations
2131:{\displaystyle Z=\left}
75:, often abbreviated to
37:) is the mass ratio of
3253:Hutchinson Educational
3187:
2652:
2633:
2555:
2472:
2262:
2132:
1979:
1936:
1741:
1546:
1412:
1169:
1066:
845:
672:fuel-to-oxidizer ratio
662:fuel-to-oxidizer ratio
606:
496:
335:Other types of engines
190:revolutions per minute
73:stoichiometric mixture
3403:Eckerlin, Herbert M.
3346:, accessed 2011-05-25
3188:
2650:
2634:
2556:
2473:
2263:
2133:
1993:Further information:
1980:
1937:
1750:or, equivalently, as
1742:
1547:
1413:
1170:
1067:
858:represents the mass,
846:
607:
530: > 1.0.
497:
435:Fuel–air ratio (FAR)
103:Air-fuel ratio meters
3317:Combustion and Flame
3275:See Example 15.3 in
3213:Air–fuel ratio meter
2714:
2676:air–fuel ratio meter
2572:
2496:
2320:
2149:
2010:
1956:
1757:
1562:
1423:
1224:
1082:
914:
649:
560:
457:
329:air–fuel ratio meter
199:Catalytic converters
117:air–fuel ratio gauge
109:air-fuel ratio meter
3449:catalytic converter
2651:Ideal stoichiometry
1896:
1869:
1856:
1827:
1800:
1787:
1701:
1674:
1661:
1632:
1605:
1592:
1507:
1485:
1472:
1308:
1286:
1273:
1140:
1118:
1105:
972:
950:
937:
428:of 0.850 to 0.901.
216:evaporative cooling
3499:Engineering ratios
3494:Chemical reactions
3183:
3181:
2665:gas-fired turbines
2653:
2629:
2551:
2468:
2258:
2128:
1975:
1932:
1884:
1857:
1844:
1815:
1788:
1775:
1737:
1689:
1662:
1649:
1620:
1593:
1580:
1542:
1495:
1473:
1460:
1408:
1296:
1274:
1261:
1165:
1128:
1106:
1093:
1062:
960:
938:
925:
891:) and one mole of
841:
674:
664:
602:
492:
135:or lambda sensor.
3460:Kamm, Richard W.
3164:
3143:
3106:
3085:
3052:
3019:
2995:
2986:
2973:
2930:
2909:
2872:
2851:
2818:
2785:
2761:
2752:
2739:
2627:
2549:
2528:
2506:
2462:
2459:
2256:
2122:
1973:
1924:
1911:
1908:
1887:
1860:
1847:
1818:
1791:
1778:
1729:
1716:
1713:
1692:
1665:
1652:
1623:
1596:
1583:
1534:
1520:
1511:
1498:
1476:
1463:
1441:
1432:
1400:
1387:
1321:
1312:
1299:
1277:
1264:
1242:
1233:
1157:
1144:
1131:
1109:
1096:
1054:
1041:
976:
963:
941:
928:
839:
836:
825:
810:
793:
778:
763:
760:
749:
734:
717:
702:
687:
683:
673:
663:
600:
597:
490:
421:of 1.00 exactly.
16:(Redirected from
3516:
3480:
3478:
3477:
3431:
3430:
3428:
3426:
3421:on 27 March 2014
3420:
3409:
3400:
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3391:
3389:
3378:
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3371:
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3367:
3361:
3353:
3347:
3339:
3333:
3332:
3314:
3305:
3299:
3298:
3273:
3267:
3266:
3244:
3218:Mass flow sensor
3192:
3190:
3189:
3184:
3182:
3175:
3174:
3173:
3162:
3141:
3127:
3126:
3117:
3116:
3115:
3104:
3083:
3062:
3050:
3017:
2993:
2984:
2983:
2982:
2971:
2941:
2940:
2939:
2928:
2907:
2893:
2892:
2883:
2882:
2881:
2870:
2849:
2828:
2816:
2783:
2759:
2750:
2749:
2748:
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2702:
2701:
2700:
2692:
2691:
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2636:
2635:
2630:
2628:
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2624:
2608:
2607:
2606:
2590:
2585:
2560:
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2557:
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2550:
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2529:
2527:
2513:
2508:
2507:
2504:
2477:
2475:
2474:
2469:
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2457:
2456:
2455:
2442:
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2427:
2426:
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2408:
2407:
2406:
2405:
2392:
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2390:
2377:
2376:
2375:
2358:
2346:
2337:
2336:
2335:
2267:
2265:
2264:
2259:
2257:
2255:
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2252:
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2237:
2226:
2225:
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2223:
2210:
2209:
2208:
2197:
2192:
2191:
2190:
2169:
2137:
2135:
2134:
2129:
2127:
2123:
2121:
2120:
2119:
2118:
2099:
2098:
2097:
2077:
2076:
2075:
2074:
2055:
2054:
2053:
2040:
2039:
2038:
2024:
2003:, Z, defined as
2001:mixture fraction
1995:Mixture fraction
1989:Mixture fraction
1984:
1982:
1981:
1976:
1974:
1966:
1941:
1939:
1938:
1933:
1925:
1917:
1912:
1910:
1909:
1906:
1904:
1900:
1899:
1898:
1897:
1895:
1892:
1885:
1877:
1872:
1871:
1870:
1868:
1865:
1858:
1855:
1852:
1845:
1831:
1830:
1829:
1828:
1826:
1823:
1816:
1808:
1803:
1802:
1801:
1799:
1796:
1789:
1786:
1783:
1776:
1767:
1746:
1744:
1743:
1738:
1730:
1722:
1717:
1715:
1714:
1711:
1709:
1705:
1704:
1703:
1702:
1700:
1697:
1690:
1682:
1677:
1676:
1675:
1673:
1670:
1663:
1660:
1657:
1650:
1636:
1635:
1634:
1633:
1631:
1628:
1621:
1613:
1608:
1607:
1606:
1604:
1601:
1594:
1591:
1588:
1581:
1572:
1551:
1549:
1548:
1543:
1535:
1527:
1522:
1521:
1518:
1516:
1512:
1510:
1509:
1508:
1506:
1503:
1496:
1488:
1487:
1486:
1484:
1481:
1474:
1471:
1468:
1461:
1453:
1443:
1442:
1439:
1433:
1430:
1417:
1415:
1414:
1409:
1401:
1393:
1388:
1386:
1363:
1328:
1323:
1322:
1319:
1317:
1313:
1311:
1310:
1309:
1307:
1304:
1297:
1289:
1288:
1287:
1285:
1282:
1275:
1272:
1269:
1262:
1254:
1244:
1243:
1240:
1234:
1231:
1200:
1199:
1195:
1174:
1172:
1171:
1166:
1158:
1150:
1145:
1143:
1142:
1141:
1139:
1136:
1129:
1121:
1120:
1119:
1117:
1114:
1107:
1104:
1101:
1094:
1086:
1071:
1069:
1068:
1063:
1055:
1047:
1042:
1040:
1017:
982:
977:
975:
974:
973:
971:
968:
961:
953:
952:
951:
949:
946:
939:
936:
933:
926:
918:
906:
905:
904:
890:
889:
888:
880:
879:
850:
848:
847:
842:
840:
838:
837:
834:
832:
828:
827:
826:
823:
817:
812:
811:
808:
796:
795:
794:
791:
785:
780:
779:
776:
769:
764:
762:
761:
758:
756:
752:
751:
750:
747:
741:
736:
735:
732:
720:
719:
718:
715:
709:
704:
703:
700:
693:
688:
686:
685:
684:
681:
675:
671:
661:
659:
611:
609:
608:
603:
601:
599:
598:
595:
593:
581:
570:
501:
499:
498:
493:
491:
489:
475:
470:
398:
397:
396:
382:
381:
380:
344:Other terms used
192:
173:
172:
168:
165:
159:
158:
154:
151:
21:
3524:
3523:
3519:
3518:
3517:
3515:
3514:
3513:
3484:
3483:
3475:
3473:
3443:HowStuffWorks:
3440:
3435:
3434:
3424:
3422:
3418:
3407:
3401:
3397:
3387:
3385:
3380:
3379:
3375:
3365:
3363:
3359:
3355:
3354:
3350:
3340:
3336:
3312:
3306:
3302:
3295:
3274:
3270:
3263:
3245:
3241:
3236:
3199:
3180:
3179:
3169:
3165:
3137:
3122:
3118:
3111:
3107:
3079:
3063:
2978:
2974:
2949:
2946:
2945:
2935:
2931:
2903:
2888:
2884:
2877:
2873:
2845:
2829:
2744:
2740:
2721:
2717:
2715:
2712:
2711:
2706:
2699:
2696:
2695:
2694:
2690:
2687:
2686:
2685:
2683:
2645:
2614:
2613:
2609:
2596:
2595:
2591:
2589:
2575:
2573:
2570:
2569:
2538:
2533:
2517:
2512:
2503:
2499:
2497:
2494:
2493:
2451:
2450:
2446:
2436:
2435:
2431:
2415:
2414:
2410:
2409:
2401:
2400:
2396:
2386:
2385:
2381:
2365:
2364:
2360:
2359:
2357:
2350:
2345:
2341:
2328:
2327:
2323:
2321:
2318:
2317:
2312:
2305:
2298:
2291:
2284:
2277:
2248:
2247:
2243:
2233:
2232:
2228:
2227:
2219:
2218:
2214:
2204:
2203:
2199:
2198:
2196:
2171:
2170:
2159:
2158:
2150:
2147:
2146:
2108:
2107:
2103:
2087:
2086:
2082:
2078:
2064:
2063:
2059:
2049:
2048:
2044:
2034:
2033:
2029:
2025:
2023:
2019:
2011:
2008:
2007:
1997:
1991:
1965:
1957:
1954:
1953:
1916:
1905:
1893:
1888:
1883:
1882:
1878:
1873:
1866:
1861:
1853:
1848:
1843:
1842:
1838:
1837:
1833:
1832:
1824:
1819:
1814:
1813:
1809:
1804:
1797:
1792:
1784:
1779:
1774:
1773:
1769:
1768:
1766:
1758:
1755:
1754:
1721:
1710:
1698:
1693:
1688:
1687:
1683:
1678:
1671:
1666:
1658:
1653:
1648:
1647:
1643:
1642:
1638:
1637:
1629:
1624:
1619:
1618:
1614:
1609:
1602:
1597:
1589:
1584:
1579:
1578:
1574:
1573:
1571:
1563:
1560:
1559:
1526:
1517:
1504:
1499:
1494:
1493:
1489:
1482:
1477:
1469:
1464:
1459:
1458:
1454:
1452:
1448:
1447:
1438:
1434:
1429:
1424:
1421:
1420:
1392:
1364:
1329:
1327:
1318:
1305:
1300:
1295:
1294:
1290:
1283:
1278:
1270:
1265:
1260:
1259:
1255:
1253:
1249:
1248:
1239:
1235:
1230:
1225:
1222:
1221:
1212:
1208:
1204:
1197:
1193:
1192:
1190:
1186:
1149:
1137:
1132:
1127:
1126:
1122:
1115:
1110:
1102:
1097:
1092:
1091:
1087:
1085:
1083:
1080:
1079:
1046:
1018:
983:
981:
969:
964:
959:
958:
954:
947:
942:
934:
929:
924:
923:
919:
917:
915:
912:
911:
903:
900:
899:
898:
896:
887:
884:
883:
882:
878:
875:
874:
873:
871:
833:
822:
818:
813:
807:
803:
802:
798:
797:
790:
786:
781:
775:
771:
770:
768:
757:
746:
742:
737:
731:
727:
726:
722:
721:
714:
710:
705:
699:
695:
694:
692:
680:
676:
669:
665:
658:
650:
647:
646:
632:
594:
583:
582:
571:
569:
561:
558:
557:
512:
479:
474:
460:
458:
455:
454:
437:
409:
399:), and various
395:
392:
391:
390:
388:
379:
376:
375:
374:
372:
354:
346:
337:
265:
261:
257:
253:
249:
228:
187:
180:
170:
166:
163:
161:
156:
152:
149:
147:
105:
81:nitrogen oxides
28:
23:
22:
15:
12:
11:
5:
3522:
3512:
3511:
3506:
3501:
3496:
3482:
3481:
3457:
3451:
3445:fuel injection
3439:
3438:External links
3436:
3433:
3432:
3395:
3373:
3348:
3334:
3323:(3): 546–556.
3300:
3293:
3268:
3261:
3238:
3237:
3235:
3232:
3231:
3230:
3225:
3220:
3215:
3210:
3205:
3198:
3195:
3194:
3193:
3178:
3172:
3168:
3161:
3158:
3155:
3152:
3149:
3146:
3140:
3136:
3133:
3130:
3125:
3121:
3114:
3110:
3103:
3100:
3097:
3094:
3091:
3088:
3082:
3078:
3075:
3072:
3069:
3066:
3064:
3061:
3058:
3055:
3049:
3046:
3043:
3040:
3037:
3034:
3031:
3028:
3025:
3022:
3016:
3013:
3010:
3007:
3004:
3001:
2998:
2992:
2989:
2981:
2977:
2970:
2967:
2964:
2961:
2958:
2955:
2952:
2948:
2947:
2944:
2938:
2934:
2927:
2924:
2921:
2918:
2915:
2912:
2906:
2902:
2899:
2896:
2891:
2887:
2880:
2876:
2869:
2866:
2863:
2860:
2857:
2854:
2848:
2844:
2841:
2838:
2835:
2832:
2830:
2827:
2824:
2821:
2815:
2812:
2809:
2806:
2803:
2800:
2797:
2794:
2791:
2788:
2782:
2779:
2776:
2773:
2770:
2767:
2764:
2758:
2755:
2747:
2743:
2736:
2733:
2730:
2727:
2724:
2720:
2719:
2704:
2697:
2688:
2655:In industrial
2644:
2641:
2640:
2639:
2623:
2620:
2617:
2612:
2605:
2602:
2599:
2594:
2588:
2584:
2581:
2578:
2563:
2562:
2547:
2544:
2541:
2537:
2532:
2526:
2523:
2520:
2516:
2511:
2502:
2479:
2478:
2466:
2454:
2449:
2445:
2439:
2434:
2430:
2424:
2421:
2418:
2413:
2404:
2399:
2395:
2389:
2384:
2380:
2374:
2371:
2368:
2363:
2356:
2353:
2349:
2344:
2340:
2334:
2331:
2326:
2310:
2303:
2296:
2289:
2282:
2275:
2270:
2269:
2251:
2246:
2242:
2236:
2231:
2222:
2217:
2213:
2207:
2202:
2195:
2189:
2186:
2183:
2180:
2177:
2174:
2168:
2165:
2162:
2157:
2154:
2140:
2139:
2126:
2117:
2114:
2111:
2106:
2102:
2096:
2093:
2090:
2085:
2081:
2073:
2070:
2067:
2062:
2058:
2052:
2047:
2043:
2037:
2032:
2028:
2022:
2018:
2015:
1990:
1987:
1986:
1985:
1972:
1969:
1964:
1961:
1943:
1942:
1931:
1928:
1923:
1920:
1915:
1903:
1891:
1881:
1876:
1864:
1851:
1841:
1836:
1822:
1812:
1807:
1795:
1782:
1772:
1765:
1762:
1748:
1747:
1736:
1733:
1728:
1725:
1720:
1708:
1696:
1686:
1681:
1669:
1656:
1646:
1641:
1627:
1617:
1612:
1600:
1587:
1577:
1570:
1567:
1553:
1552:
1541:
1538:
1533:
1530:
1525:
1515:
1502:
1492:
1480:
1467:
1457:
1451:
1446:
1437:
1428:
1418:
1407:
1404:
1399:
1396:
1391:
1385:
1382:
1379:
1376:
1373:
1370:
1367:
1362:
1359:
1356:
1353:
1350:
1347:
1344:
1341:
1338:
1335:
1332:
1326:
1316:
1303:
1293:
1281:
1268:
1258:
1252:
1247:
1238:
1229:
1215:
1214:
1210:
1206:
1202:
1188:
1184:
1176:
1175:
1164:
1161:
1156:
1153:
1148:
1135:
1125:
1113:
1100:
1090:
1073:
1072:
1061:
1058:
1053:
1050:
1045:
1039:
1036:
1033:
1030:
1027:
1024:
1021:
1016:
1013:
1010:
1007:
1004:
1001:
998:
995:
992:
989:
986:
980:
967:
957:
945:
932:
922:
901:
885:
876:
852:
851:
831:
821:
816:
806:
801:
789:
784:
774:
767:
755:
745:
740:
730:
725:
713:
708:
698:
691:
679:
668:
657:
654:
631:
624:
613:
612:
592:
589:
586:
580:
577:
574:
568:
565:
511:
504:
503:
502:
488:
485:
482:
478:
473:
469:
466:
463:
440:Fuel–air ratio
436:
433:
407:
393:
377:
369:carbon dioxide
353:
350:
345:
342:
336:
333:
325:oxygen sensors
268:
267:
263:
259:
255:
251:
247:
232:stoichiometric
227:
224:
179:
176:
125:air–fuel gauge
121:air–fuel meter
115:. Also called
104:
101:
67:stoichiometric
55:dust explosion
31:Air–fuel ratio
26:
18:Air-fuel ratio
9:
6:
4:
3:
2:
3521:
3510:
3507:
3505:
3502:
3500:
3497:
3495:
3492:
3491:
3489:
3472:on 2010-11-20
3471:
3467:
3463:
3458:
3456:
3452:
3450:
3446:
3442:
3441:
3417:
3413:
3406:
3399:
3383:
3377:
3358:
3352:
3345:
3344:
3338:
3330:
3326:
3322:
3318:
3311:
3304:
3296:
3294:9780072884951
3290:
3286:
3282:
3281:
3272:
3264:
3262:0-09-110711-3
3258:
3254:
3250:
3243:
3239:
3229:
3226:
3224:
3221:
3219:
3216:
3214:
3211:
3209:
3206:
3204:
3201:
3200:
3170:
3131:
3128:
3123:
3112:
3073:
3070:
3067:
3065:
2979:
2936:
2897:
2894:
2889:
2878:
2839:
2836:
2833:
2831:
2745:
2710:
2709:
2708:
2681:
2677:
2673:
2668:
2666:
2662:
2658:
2657:fired heaters
2649:
2621:
2618:
2610:
2603:
2600:
2592:
2586:
2568:
2567:
2566:
2545:
2542:
2539:
2535:
2530:
2524:
2521:
2518:
2514:
2509:
2500:
2492:
2491:
2490:
2488:
2485:(lambda) and
2484:
2464:
2447:
2443:
2432:
2428:
2422:
2419:
2411:
2397:
2393:
2382:
2378:
2372:
2369:
2361:
2354:
2351:
2347:
2342:
2338:
2324:
2316:
2315:
2314:
2309:
2302:
2295:
2288:
2281:
2274:
2244:
2240:
2229:
2215:
2211:
2200:
2193:
2155:
2152:
2145:
2144:
2143:
2124:
2115:
2112:
2104:
2100:
2094:
2091:
2083:
2079:
2071:
2068:
2060:
2056:
2045:
2041:
2030:
2026:
2020:
2016:
2013:
2006:
2005:
2004:
2002:
1996:
1970:
1967:
1962:
1959:
1952:
1951:
1950:
1947:
1929:
1926:
1921:
1918:
1913:
1901:
1889:
1879:
1874:
1862:
1849:
1839:
1834:
1820:
1810:
1805:
1793:
1780:
1770:
1763:
1760:
1753:
1752:
1751:
1734:
1731:
1726:
1723:
1718:
1706:
1694:
1684:
1679:
1667:
1654:
1644:
1639:
1625:
1615:
1610:
1598:
1585:
1575:
1568:
1565:
1558:
1557:
1556:
1539:
1536:
1531:
1528:
1523:
1513:
1500:
1490:
1478:
1465:
1455:
1449:
1444:
1419:
1405:
1402:
1397:
1394:
1389:
1380:
1377:
1374:
1368:
1365:
1357:
1354:
1351:
1348:
1345:
1342:
1339:
1333:
1330:
1324:
1314:
1301:
1291:
1279:
1266:
1256:
1250:
1245:
1220:
1219:
1218:
1182:
1181:
1180:
1162:
1159:
1154:
1151:
1146:
1133:
1123:
1111:
1098:
1088:
1078:
1077:
1076:
1059:
1056:
1051:
1048:
1043:
1034:
1031:
1028:
1022:
1019:
1011:
1008:
1005:
1002:
999:
996:
993:
987:
984:
978:
965:
955:
943:
930:
920:
910:
909:
908:
894:
869:
863:
861:
857:
829:
819:
814:
804:
799:
787:
782:
772:
765:
753:
743:
738:
728:
723:
711:
706:
696:
689:
655:
652:
645:
644:
643:
641:
637:
629:
623:
620:
618:
566:
563:
556:
555:
554:
552:
548:
544:
540:
536:
531:
529:
525:
521:
517:
509:
476:
471:
453:
452:
451:
449:
445:
441:
432:
429:
427:
422:
420:
416:
411:
406:
402:
386:
370:
365:
360:
358:
349:
341:
332:
330:
326:
322:
317:
316:oxygen sensor
313:
309:
305:
301:
299:
293:
289:
285:
281:
277:
273:
245:
244:
243:
241:
237:
233:
223:
221:
220:cylinder head
217:
212:
206:
204:
203:exhaust gases
200:
196:
191:
184:
175:
145:
140:
136:
134:
130:
129:oxygen sensor
126:
122:
118:
114:
110:
100:
98:
94:
90:
86:
82:
78:
74:
70:
68:
63:
58:
56:
52:
48:
45:present in a
44:
40:
36:
32:
19:
3474:. Retrieved
3470:the original
3465:
3423:. Retrieved
3416:the original
3411:
3398:
3386:. Retrieved
3376:
3364:. Retrieved
3351:
3342:
3337:
3320:
3316:
3303:
3279:
3271:
3248:
3242:
2680:mass balance
2669:
2654:
2564:
2486:
2482:
2480:
2307:
2300:
2293:
2286:
2279:
2272:
2271:
2141:
1998:
1948:
1944:
1749:
1554:
1216:
1177:
1074:
864:
859:
855:
853:
639:
635:
633:
627:
621:
616:
614:
550:
546:
542:
538:
534:
532:
527:
523:
519:
515:
513:
507:
439:
438:
430:
425:
423:
418:
412:
404:
363:
361:
356:
355:
347:
338:
300:-butyl ether
297:
279:
276:rich mixture
272:lean mixture
269:
258:→ 16 CO
229:
207:
185:
181:
141:
137:
132:
124:
120:
116:
108:
106:
76:
72:
65:
59:
34:
30:
29:
3285:McGraw-Hill
2661:power plant
1217:This gives
1205:→ 2 CO
444:gas turbine
262:+ 18 H
188:6,000
97:water vapor
93:air density
3488:Categories
3476:2009-03-18
3251:. London:
3234:References
3223:Combustion
3208:AFR sensor
1209:+ 3 H
321:carburetor
288:iso-octane
266:O + energy
250:+ 2 C
195:Otto cycle
133:AFR sensor
69:combustion
47:combustion
3139:%
3081:%
3071:−
3068:≈
2969:%
2905:%
2847:%
2837:−
2834:≈
2735:%
2565:assuming
2546:ϕ
2525:λ
2515:λ
2444:×
2429:×
2394:×
2379:×
2241:×
2212:×
2042:−
1971:λ
1960:ϕ
1761:ϕ
1566:ϕ
1378:×
1369:×
1355:×
1343:×
1334:×
1032:×
1023:×
1009:×
997:×
988:×
653:ϕ
564:λ
413:For pure
246:25 O
85:lean-burn
3197:See also
385:nitrogen
308:methanol
236:gasoline
211:knocking
3509:Engines
3425:29 July
3388:29 July
3366:29 July
2672:oxidant
1201: O
1196:⁄
401:alkanes
357:Mixture
352:Mixture
304:ethanol
296:methyl
292:alkanes
284:heptane
169:⁄
155:⁄
3291:
3259:
3163:
3142:
3105:
3084:
3074:0.1208
3051:
3018:
2994:
2985:
2972:
2929:
2908:
2871:
2850:
2840:0.1433
2817:
2784:
2760:
2751:
2738:
2142:where
1060:0.9375
893:oxygen
868:ethane
854:where
596:stoich
415:octane
240:octane
89:oxygen
77:stoich
60:In an
3419:(PDF)
3408:(PDF)
3360:(PDF)
3313:(PDF)
3132:0.186
2898:0.214
1922:0.286
1727:0.268
1724:0.938
1540:0.286
1406:0.268
302:) or
123:, or
3427:2013
3390:2013
3368:2013
3289:ISBN
3257:ISBN
2705:mass
2306:and
2292:and
2278:and
809:fuel
777:fuel
733:fuel
701:fuel
634:The
408:fuel
364:mass
312:MTBE
298:tert
286:and
230:The
160:and
144:LEDs
43:fuel
3325:doi
3321:154
2283:O,0
2276:F,0
1930:3.5
1735:3.5
1532:3.5
1398:112
1366:3.5
383:),
107:An
39:air
35:AFR
3490::
3464:.
3447:,
3410:.
3319:.
3315:.
3287:.
3255:.
2659:,
2505:st
1907:st
1712:st
1519:st
1440:st
1395:30
1381:16
1346:12
1320:st
1241:st
1191:+
1052:32
1049:30
1035:16
1000:12
835:st
824:ox
792:ox
759:st
748:ox
716:ox
682:st
638:,
553::
410:.
373:CO
331:.
256:18
157:16
119:,
3479:.
3429:.
3392:.
3370:.
3331:.
3327::
3297:.
3265:.
3177:)
3171:2
3167:O
3160:s
3157:s
3154:e
3151:c
3148:x
3145:e
3135:(
3129:+
3124:2
3120:)
3113:2
3109:O
3102:s
3099:s
3096:e
3093:c
3090:x
3087:e
3077:(
3060:s
3057:a
3054:g
3048:n
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3042:i
3039:t
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3033:u
3030:b
3027:m
3024:o
3021:c
3015:e
3012:n
3009:a
3006:p
3003:o
3000:r
2997:p
2991:n
2988:i
2980:2
2976:O
2966:e
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2943:)
2937:2
2933:O
2926:s
2923:s
2920:e
2917:c
2914:x
2911:e
2901:(
2895:+
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2886:)
2879:2
2875:O
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2826:s
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2808:i
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2790:o
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2778:n
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2772:p
2769:o
2766:r
2763:p
2757:n
2754:i
2746:2
2742:O
2732:s
2729:s
2726:a
2723:M
2698:8
2693:H
2689:3
2684:C
2622:0
2619:,
2616:F
2611:Y
2604:0
2601:,
2598:O
2593:Y
2587:=
2583:R
2580:F
2577:A
2561:,
2543:+
2540:1
2536:1
2531:=
2522:+
2519:1
2510:=
2501:Z
2487:Φ
2483:λ
2465:]
2453:F
2448:v
2438:F
2433:W
2423:0
2420:,
2417:O
2412:Y
2403:O
2398:v
2388:O
2383:W
2373:0
2370:,
2367:F
2362:Y
2355:+
2352:1
2348:1
2343:[
2339:=
2333:t
2330:s
2325:Z
2311:O
2308:v
2304:F
2301:v
2297:O
2294:W
2290:F
2287:W
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2273:Y
2268:,
2250:F
2245:v
2235:F
2230:W
2221:O
2216:v
2206:O
2201:W
2194:=
2188:h
2185:c
2182:i
2179:o
2176:t
2173:s
2167:R
2164:F
2161:A
2156:=
2153:s
2138:,
2125:]
2116:0
2113:,
2110:O
2105:Y
2101:+
2095:0
2092:,
2089:F
2084:Y
2080:s
2072:0
2069:,
2066:O
2061:Y
2057:+
2051:O
2046:Y
2036:F
2031:Y
2027:s
2021:[
2017:=
2014:Z
1968:1
1963:=
1927:=
1919:1
1914:=
1902:)
1890:2
1886:O
1880:n
1875:/
1863:6
1859:H
1850:2
1846:C
1840:n
1835:(
1821:2
1817:O
1811:n
1806:/
1794:6
1790:H
1781:2
1777:C
1771:n
1764:=
1732:=
1719:=
1707:)
1695:2
1691:O
1685:m
1680:/
1668:6
1664:H
1655:2
1651:C
1645:m
1640:(
1626:2
1622:O
1616:m
1611:/
1599:6
1595:H
1586:2
1582:C
1576:m
1569:=
1537:=
1529:1
1524:=
1514:)
1501:2
1497:O
1491:n
1479:6
1475:H
1466:2
1462:C
1456:n
1450:(
1445:=
1436:)
1427:(
1403:=
1390:=
1384:)
1375:2
1372:(
1361:)
1358:1
1352:6
1349:+
1340:2
1337:(
1331:1
1325:=
1315:)
1302:2
1298:O
1292:m
1280:6
1276:H
1267:2
1263:C
1257:m
1251:(
1246:=
1237:)
1228:(
1213:O
1211:2
1207:2
1203:2
1198:2
1194:7
1189:6
1187:H
1185:2
1183:C
1163:1
1160:=
1155:1
1152:1
1147:=
1134:2
1130:O
1124:n
1112:6
1108:H
1099:2
1095:C
1089:n
1057:=
1044:=
1038:)
1029:2
1026:(
1020:1
1015:)
1012:1
1006:6
1003:+
994:2
991:(
985:1
979:=
966:2
962:O
956:m
944:6
940:H
931:2
927:C
921:m
902:2
897:O
895:(
886:6
881:H
877:2
872:C
870:(
860:n
856:m
830:)
820:n
815:/
805:n
800:(
788:n
783:/
773:n
766:=
754:)
744:m
739:/
729:m
724:(
712:m
707:/
697:m
690:=
678:)
667:(
656:=
640:Φ
630:)
628:Φ
617:λ
591:R
588:F
585:A
579:R
576:F
573:A
567:=
551:λ
547:λ
543:λ
539:λ
535:λ
528:λ
524:λ
520:λ
516:λ
510:)
508:λ
487:R
484:F
481:A
477:1
472:=
468:R
465:A
462:F
426:λ
419:λ
405:m
394:2
389:N
387:(
378:2
371:(
306:/
282:-
280:n
264:2
260:2
254:H
252:8
248:2
171:8
167:5
164:+
162:2
153:1
150:+
148:2
33:(
20:)
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