Performance assessment of simple and modified cycle turboshaft gas turbines

This paper focuses on investigations encompassing comparative assessment of gas turbine cycle options. More specifically, investigation was carried out of technical performance of turboshaft engine cycles based on existing simple cycle (SC) and its projected modified cycles for civil helicopter application. Technically, thermal efficiency, specific fuel consumption, and power output are of paramount importance to the overall performance of gas turbine engines. In course of carrying out this research, turbomatch software established at Cranfield University based on gas turbine theory was applied to conduct simulation of a simple cycle (baseline) two-spool helicopter turboshaft engine model with free power turbine. Similarly, some modified gas turbine cycle configurations incorporating unconventional components, such as engine cycle with low pressure compressor (LPC) zero-staged, recuperated engine cycle, and intercooled/recuperated (ICR) engine cycle, were also simulated. In doing so, design point (DP) and off-design point (OD) performances of the engine models were established. The percentage changes in performance parameters of the modified cycle engines over the simple cycle were evaluated and it was found that to a large extent, the modified engine cycles with unconventional components exhibit better performances in terms of thermal efficiency and specific fuel consumption than the traditional simple cycle engine. This research made use of public domain open source references.