The Otto cycle is primarily associated with which type of heat engine?

The Otto cycle is fundamentally linked to internal combustion engines, which utilize the cycle to convert fuel into mechanical energy. This cycle consists of specific processes: two adiabatic (isentropic) processes and two isochoric (constant volume) processes.

In an internal combustion engine, the Otto cycle involves the intake of an air-fuel mixture, which is compressed to a high pressure and temperature, ignited by a spark plug, and then undergoes an expansion stroke that drives the piston. This series of processes is pivotal for the functioning of gasoline engines, which are commonly known to operate on the Otto cycle.

In contrast, gas turbine engines operate using a different thermodynamic cycle, specifically the Brayton cycle; steam engines utilize the Rankine cycle; and refrigeration systems work based on the vapor-compression cycle or absorption cycle. Therefore, the association of the Otto cycle with internal combustion engines is properly identified as the correct context in this scenario.