Holistic performance evaluation of a turbofan featuring pressure gain combustion for a short-range mission

Abstract

Aviation is at the center of public interest because of its environmental impact, such as noise and pollutant emissions. Evolutionary technologies are not expected to be sufficient to contribute significantly to the 2050 CO2 emissions reduction targets. This could change if the constant pressure combustion of the Joule cycle could be replaced with a constant volume combustion (pressure gain combustion, PGC). However, PGC comes with a major drawback of a periodic, highly unsteady process that potentially reduces the stability and efficiency of the adjacent compressor and turbine. Furthermore, changes to the secondary air system (SAS) are required since the driving force of SAS stems from the pressure loss in the conventional combustor. Despite the lasting prevalence of pressure gain combustion, there is no whole system analysis taking into account not only the beneficial aspects of PGC, but also the detrimental effects on the SAS and turbo components. To close that gap, a zero-dimensional whole engine model is created. That model accounts for the individual effects of PGC. A comprehensive design methodology identifies optimum engine specifications for a short-range mission. By comparing the results of the PGC turbofan to a conventional turbofan, an SFC improvement of 3.3% was identified.