Chapter 21, Problem 73EAP

The gasoline engine in your car can be modeled as the Otto

cycle shown in FIGURE CP21.73. A fuel-air mixture is sprayed into

the cylinder at point l, where the piston is at its farthest distance

from the spark plug. This mixture is compressed as the piston

moves toward the spark plug during the adiabatic compression

stroke. The spark plug fires at point 2, releasing heat energy that

had been stored in the gasoline. The fuel burns so quickly that the

piston doesn't have time to move, so the heating is an isochoric

process. The hot, high-pressure gas then pushes the piston out-

ward during the power stroke. Finally, an exhaust value opens to

allow the gas temperature and pressure to drop back to their initial

values before starting the cycle over again.