An integrated design framework for micro gas turbines based on techno-economic assessment: From concept to experimental validation

Vertical Takeoff and Landing aircraft require power generation systems with exceptional power density and economic efficiency, for which micro gas turbine generators offer a promising solution. However, existing design methods often lack a systematic integration of economic considerations with technical performance under stringent weight and compactness constraints. This paper proposes an integrated design framework for high-specific-power micro gas turbine generators, incorporating a life cycle cost model to guide thermodynamic cycle design. The framework addresses key miniaturization challenges through advanced component design methodologies, including: (1) micro radial turbomachinery design accounting for heat and mass leakage (2) a compact combustor design with optimized fuel-air mixing, and (3) a cross-wavy primary surface recuperator design based on a composite evaluation criterion. A 6 kW prototype was designed, manufactured, and experimentally validated. Component-level tests demonstrated a compressor isentropic efficiency of 79.45% and a turbine efficiency of 87.60%, while the recuperator achieved a power-to-weight ratio of 16.1 kW/kg with an effectiveness of 0.7. System-level testing of the unrecuperated core achieved a power output of 6.2 kW and a thermal efficiency of 9.4% at 152,000 rpm, establishing a validated basis for achieving a projected recuperated efficiency exceeding 20%. These results confirm that the proposed design methodologies successfully meet the demanding performance targets, providing a reliable pathway for developing high-power-density micro gas turbine generators.