Abstract
In this study, we developed analytical models of a single-cylinder and a split-cycle air engine using commercial numerical simulation software Matlab. We will discuss how the piston reciprocating inertia and friction between piston rings and cylinder wall affect the air engine performance. Single-cylinder air engine output performance is limited by its maximum volume and the expansion efficiency. The split-cycle air engine was designed to improve the efficiency of use of compressed air by two cylinders with different sizes. And we will discuss about the simulate performance of split-cycle air engine. In the experiment, we transform the four-stroke internal combustion engine to two-stroke air engine by redesigning the valve timing. We will discuss the difference between simulation and experiment with its energy efficiency and power loss.