Performance evaluation of an axial-flow gas turbine compressor using methanol droplets as the cooling medium

Abstract

This study employs ANSYS CFX to analyze wet compression technology in the NASA Stage 35 axial compressor. A primary challenge of wet compression is the risk of blade erosion caused by slow-evaporating or poorly atomized droplets. To mitigate this, methanol was selected as the evaporative coolant due to its high volatility, low surface tension, and rapid evaporation. These properties promote the formation of a fine, uniform mist, minimizing the development of eroding liquid films and large droplets. The analysis confirms that this approach successfully averts erosion pitfalls while delivering significant performance gains. The latent heat of vaporization from the methanol notably reduced the compressor outlet temperature by 8.1 K. This intercooling effect increased the flow velocity and stage Mach number. Consequently, the outlet pressure rose by 1.378%, accompanied by an increase in mass flow rate. These combined factors led to a substantial 2.44% improvement in isentropic efficiency. These quantitative results demonstrate that methanol-based wet compression is a viable technique for enhancing compressor performance. The findings point toward a clear pathway for achieving higher power output and efficiency in gas turbine engines, mitigating the performance degradation common in hot environments without the associated risk of component wear.