Multidisciplinary Screening of a 178 kN Class Geared Turbofan with Explicit Mission Auditing and Independent Uncertainty Checks

Abstract A computational audit examines cycle matching, hot-section protection, parallel rotor screening, and uncertainty for a 177.93 kN geared turbofan. Constant-property cycle balances, analytic component maps, fixed nozzle areas, a three-node transient thermal network, and a conceptual flexible rotor are used. The selected static point has bypass ratio 12.99, overall pressure ratio 45.18, turbine-inlet temperature 1450 K, and thrust-specific fuel consumption 22.67 kg/(kN h). Reproduction exposes an inherited input in the historical Monte Carlo loop and thermal boundary conditions disconnected from matched mission states. An independent 10000-draw static holdout records six temperature exceedances and 414 nozzle-pressure-margin failures, with 95% Wilson intervals of 0.028–0.131% and 3.767–4.548%. Matched thermal coupling raises the original-cooling peak to 1255 K. One revised global law reduces the nominal peak to 1230 K at 11.50% takeoff cooling. A separate 5000-draw full-mission thermal analysis with that law frozen records 210 exceedances of 1250 K (4.20%; 95% interval 3.68–4.79%) and no numerical failures. Thus nominal recovery does not establish a mission thermal reliability claim. All eight phases converge, remain within analytic coordinate bounds, and satisfy nozzle forward-flow checks. Compressor surge margins remain undefined because instability boundaries are unavailable. Rotor response is screened over an independent speed sweep, not a recovered mission shaft-speed trajectory. The results support a reproducible conditional screening audit; full compressor operability and hardware performance remain unvalidated. The cooling result remains conditional because detailed cooling-system pressure losses and film-cooling aerodynamics are not resolved.