OTTO CYCLE DEFINITION
OTTO CYCLE DEFINITION
(OP)
I have researched a number of websites and books to get a definition of the Otto cycle.
In most cases it is synonymous with 4-stroke, and in others seems to be associated only with spark ignition.
My view is that it describes the 4-stroke cycle, whether spark or diesel, reciprocating or Wankel.
Anyone care to comment on this, and put me straight?
In most cases it is synonymous with 4-stroke, and in others seems to be associated only with spark ignition.
My view is that it describes the 4-stroke cycle, whether spark or diesel, reciprocating or Wankel.
Anyone care to comment on this, and put me straight?





RE: OTTO CYCLE DEFINITION
It says nothing about the hardware involved. It is often used as a model for spark ignited engines.
RE: OTTO CYCLE DEFINITION
Diesel cycle describes constant pressure heat addition, again regardless of engine mechanical approach.
RE: OTTO CYCLE DEFINITION
See as an example:
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I have always believed that the Otto cycle simply describes the events outlined via the PV diagram. In actuality, the Otto cycle is virtually unobtainable, as there are significant friction and heat rejection losses. The Otto cycle can functionally describe the ideal cycle, but the diesel cycle brings other factors in play, as there is no “V” curve, and the 2 cycle combines functions, very broadly covered by the PV 4 cycle graph, with significantly more losses, but regained in additional power strokes.
Franz
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RE: OTTO CYCLE DEFINITION
The Otto cycle is an attempt to break the typical SI cycle down into a series of easy to understand/analyse thermodynamic processes
The ideal Diesel cycle is the same sort of approach for a typical CI engine cycle.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: OTTO CYCLE DEFINITION
My problem (maybe where I should have started) is as follows:
A small supplier is offering me a high speed rotary engine which is still under development. It runs on kerosene type fuel, injected into the combustion chamber, and has a spark plug. It runs at a CR of about 15:1 which is high for a petrol engine but low for a diesel. He tells me it runs on the Otto cycle. There is no supercharging.
Possibly this is just a problem of nomenclature, but I feel I should understand what happens in the combustion chamber. This is a mystery to me and apparently to the supplier!
Has anyone come across such an engine?
RE: OTTO CYCLE DEFINITION
Intake, compression, power, exhaust
RE: OTTO CYCLE DEFINITION
The real cycle in an engine includes exhaust, intake, and blowdown events as well as heat transfer and a myriad of other processes.
RE: OTTO CYCLE DEFINITION
So instead of Cycle maybe it should be Otto events. Anyway I would suppose some will get what I'm trying to say here.