Otto cycle

American  

noun

Thermodynamics.

1. an idealization of the thermodynamic cycle of the internal combustion engine with air as the working substance: intake of air at atmospheric pressure, then adiabatic compression, then ignition with an increase of pressure and temperature at constant volume, then adiabatic expansion and performance of work, then a drop to atmospheric pressure at constant volume and a rejection of heat to the environment, then the exhaust of air at constant pressure.

---

Otto cycle British  

noun

1. an engine cycle used on four-stroke petrol engines ( Otto engines ) in which, ideally, combustion and rejection of heat both take place at constant volume Compare diesel cycle

---

Etymology

Origin of Otto cycle

1885–90; named after Nikolaus August Otto, 1832–91, German engineer and inventor

Example Sentences

Just as discussed for the Otto cycle in the previous section, this means that efficiency is greatest for the highest possible temperature of the hot reservoir and lowest possible temperature of the cold reservoir.

From Textbooks • Aug. 12, 2015

Along path BC of the Otto cycle, heat transfer Qh into the gas occurs at constant volume, causing a further increase in pressure and temperature.

From Textbooks • Aug. 12, 2015

Figure 15.21 This Otto cycle produces a greater work output than the one in Figure 15.20, because the starting temperature of path CD is higher and the starting temperature of path AB is lower.

From Textbooks • Aug. 12, 2015

Figure 15.20 PV diagram for a simplified Otto cycle, analogous to that employed in an internal combustion engine.

From Textbooks • Aug. 12, 2015

About 1900 the Gasmotoren Fabrik Deutz built an Otto cycle engine of 1000 b.h.p. having four cylinders each 33 in. diameter and 39.3 in. stroke, speed 135 revolutions per minute.

From Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 "G" to "Gaskell, Elizabeth" by Various