The Quest for Thermodynamic Efficiency: Atkinson Cycle Machines Versus Otto Cycle Machines

Abstract

Abstract The vigorous way in which Nicholas Otto defended his four-stroke cycle patents of 1876/77 in the courts of England, France and Germany acted as a stimulus for the development of ingenious designs to both circumvent, and improve upon, the Otto Cycle. This paper describes various engines built to operate on the Atkinson Cycle, a sound theoretical idea, first put forward in the 1880s, which offers an improved thermal efficiency over that of the Otto cycle. In this paper, the term 'Atkinson Cycle' relates to an engine, operating on an Ideal Constant Volume Thermodynamic Cycle, which has been modified to have an expansion ratio that exceeds the compression ratio.