The objective of this study is to clarify the internal flow and operating efficiency of a gas turbine compressor when the existing liquefied natural gas fuel is replaced by ammonia fuel. An unsteady full-annulus analysis was performed on 2.5 stages of an actual gas turbine compressor from the inlet guide vanes to the second stage stator blades. In addition to the opening angles at the full-load operation of natural gas fuel, the characteristic curves and flow fields were compared for the low opening angles during partial load operation. The analysis results showed that a significant impact on shock waves and incidence was observed due to the reduced mass flow rate. Furthermore, a comparison of the polytropic efficiency revealed that a significant decrease in efficiency is a concern under low opening operating conditions such as during startup and output power decreasing.
Miyazawa et al. (2026) studied this question.