What is otto cycle

Otto trial

When you hear about the Otto Trial, you probably think of him straight away Otto engine. In this post, we'll explain how the thermodynamic relationships look at this by adding the Processes using p-V and T-S diagram consider the Otto cycle. Finally, we'll show you how to do the Otto process to calculate can.

  • Procedure for the Otto process
    in the text
  • Further comparison processes
    in the text
  • Otto process: thermal efficiency
    in the text

Procedure for the Otto process

When considering the Otto engine, we make a few simplifications. Hence the Otto trial not about the exact thermodynamic process, but about one Comparison process. The idealization is done by assuming that there is no friction and that there is compression and expansion adiabatic expire. That means it no heat and material exchange with the environment gives. Furthermore, we assume an ideal gas as the working fluid.

Before we turn to the thermal changes of state, you should make sure that you have the four work cycles Sucking in, compressing, working and discharging of a gasoline engine, if not, you should first watch our video again.

Otto process in the p-V and T-S diagrams

To examine the processes, we consider the p-V and T-S diagrams of the gasoline engine cycle.

The 4 process steps or cycles in the Otto process are:

  1. Isentropic compression
  2. Isochoric heat input
  3. Isentropic expansion
  4. Isochoric heat dissipation or charge exchange

In the following we take a closer look at the sequence of the bars:

Isentropic compression 1 -> 2:

The first step is the gas isentropically compressed or compressed by the rising piston. For this work is added to the system.

Consequently increases the print and the Volume decreases. Since no heat is added or removed during an isentropic change of state, the entropy remains constant while the temperature increases.

Isochore heat supply 2 -> 3:

Next up is one isochoric heat input by burning the gas mixture. Since this process happens very quickly, the volume does not change. Only the Pressure increases. This is why one speaks of an “equal space process”. Through the heat supply the temperature rise and the entropy in the system.

Isentropic expansion 3 -> 4:

Now another follows isentropic expansionin which the piston is no longer fixed. During this process, the gas does work, which causes the Volume enlarged and the print in the system sinks. Again, there is no heat exchange. The entropy so remains constant and the Temperature drops.

Isochoric heat dissipation or gas exchange 4 -> 1: