Micro gas turbines are gaining renewed interest as range-extender engines in hybrid vehicles due to their superior power-to-weight ratio, fuel flexibility, and robust steady-state performance. However, their widespread adoption is hindered by modest efficiency and high component costs, particularly from recuperators. This study investigates the thermodynamic performance enhancement of two commercial micro gas turbines, the Capstone C-30 and C-60, through wave rotor integration as a topping device. Using Aspen Plus and Aspen Custom Modeler, three configurations were analyzed: a recuperated engine with a single wave rotor, and unrecuperated engines with a single and two cascaded wave rotors, respectively. Key performance metrics—including brake thermal efficiency, specific fuel consumption, and specific work—were evaluated across a range of wave rotor pressure ratios.
Results show that the wave rotor significantly improves power output and pressure ratio while maintaining or improving thermal efficiency. The cascaded wave rotor configuration delivered the highest gains, with power output increased by up to 80–95% and BTE reaching 32.4%. However, this also introduced challenges such as high combustor outlet temperatures (>1400 K), raising the potential for NOₓ formation and increased system complexity. A detailed sensitivity analysis confirmed that the thermodynamic benefits scale with pressure ratio up to a threshold (WR ≈ 2.6–3.0), beyond which gains diminish. The study concludes that wave rotor-enhanced MGTs, particularly when coupled with catalytic combustors, present a potentially promising solution for high-performance, low-emission hybrid vehicle range extender applications.