Stuart, K., Yan, T., and Mathias, J., "Thermodynamic Analysis of a Five-Stroke Engine with Heat Transfer and Mass Loss," SAE Technical Paper 2017-01-0633, 2017, doi:10.4271/2017-01-0633.
In this paper, the air-standard cycle analysis is performed for a 5-stroke engine to obtain the indicated thermal efficiency and power output over a range of operating points and design characteristics, including engine RPM, compression ratio, overall expansion ratio, expansion cylinder clearance volume, and transfer port volume. The results are compared with those of a baseline 4-stroke engine. This analysis is accomplished by an air-standard thermodynamic model for both engines with heat release function with heat transfer and mass loss for both the combustion cylinder and the expansion cylinder. The results indicate increased thermal efficiency and power output over the baseline 4-stroke engine, depending on the engine RPM and overall expansion ratios.