What is the Otto Cycle?

Welcome back MechanicalEI, Did you know that Nikolaus Otto devised an engine based on the Otto cycle which was twice as efficient as other engines of their time? This makes us wonder, What is the Otto cycle? Before we jump in check out the previous part of this series to learn about what co-generation is? Now, There are certain assumptions for air that we need to consider before studying the Otto cycle. It starts with the working fluid, which is air. It continuously circulates in a closed cycle. Air is considered as an ideal gas. All the processes in (ideal) power cycles are internally reversible. Combustion process is modeled by a heat-addition process from an external source. The exhaust process is modeled by a heat-rejection process that restores the working fluid (air) at its initial state. Finally, specific heats are assumed to be constant @25°C for air. We'll look at the Otto Cycle using Processes. Process 0: a mass of air is drawn into piston/cylinder arrangement at constant pressure. Process 1 is an adiabatic (isentropic) compression of the charge as the piston moves from bottom dead centre (BDC) to top dead centre (TDC). Process 2–3 is a constant-volume heat transfer to the working gas from an external source while the piston is at top dead centre. This process is intended to represent the ignition of the fuel-air mixture and the subsequent rapid burning. Process 3–4 is an adiabatic isentropic expansion also called the power stroke. Process 4–1 completes the cycle by a constant-volume process in which heat is rejected from the air while the piston is at bottom dead centre. In the final process Process 1–0 the mass of air is released to the atmosphere in a constant pressure process. . Hence, We first saw what the air cycle assumptions are and then saw what the otto cycle is?
In the next episode of MechanicalEI, find out what the diesel cycle is?

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