Performance of a Large Turbofan Engine Cycle Using a Free-Piston Engine as a Pressure-Rise Combustor

Abstract

In this project, a two-stroke free-piston was modelled in an Excel Spreadsheet uses multiple inputs for iteration to get a converged solution. A Reference Engine Cycle was modelled first based on a conventional combustor. Then an intercooler was added to the cycle, after which a constant volume combustion system was modelled. In each step, the modelling was based on a study aiming for year-2050 engines. This approach was followed in order to reach the final step which is adjusting the model to be operated on a two-stroke FPLE. The free-piston intercooled cycle gives an improvement in the Specific Fuel consumption of 21.9% for the design point, Top of Climb. 18% for the Cruise condition and 25.8% for the end of runway Take-Off comparing to the reference engine cycle. Injection fuel at high pressure in the FPLE could cause an increase in NOx and further investigation should continue on this issue.