Effect of angle of attack variation on turboprop engine performance: a digital twin-based approach
Journal of Thermal Analysis and Calorimetry, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1007/s10973-026-16301-w
- Dergi Adı: Journal of Thermal Analysis and Calorimetry
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Chemical Abstracts Core, Chimica, Compendex, Index Islamicus, INSPEC, Academic Search Ultimate (EBSCO), Engineering Source (EBSCO), Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest)
- Anahtar Kelimeler: Angle of attack, DC60, Digital twin, Hybrid-electric propulsion, Intake flow distortion, Interturbine temperature, Parallel-compressor theory, Surge margin, Turboprop engine
- Erciyes Üniversitesi Adresli: Evet
Özet
Variation of the angle of attack (AoA) changes the incidence of the flow entering an engine intake, and the resulting non-uniformity at the compressor face degrades both the efficiency and the stability margin of a gas turbine. This study quantifies that penalty for a PT6A-67-class free-turbine turboprop installed on a 19-seat regional transport aircraft, using a system-level digital twin (DT) built in Simcenter Amesim together with a complementary reduced-order (ROM) aero-thermodynamic model that supplies the intake distortion transfer path the 1D environment cannot resolve on its own. Intake total pressure recovery and the circumferential descriptor DC60 are mapped onto compressor efficiency, flow capacity, and surge margin through parallel-compressor theory. The ROM is calibrated against the certificated take-off rating of the PT6A-67D and reproduces published shaft power, interturbine temperature, residual thrust, and specific fuel consumption to within the tolerance of the open data. Across the operational envelope (0–18°) at constant power demand, pressure recovery falls from 0.985 to 0.972 and DC60 rises to 0.18. Interturbine temperature rises 17.3 K, exhaust gas temperature 14.5 K and power-specific fuel consumption 0.73%. Measured against the margins they consume; however, these are not equivalent penalties: the temperature rise absorbs about 10% of the turbine temperature margin available at that power setting, whereas the distortion consumes 29% of the available surge margin. Compressor stability, not turbine temperature, is therefore the governing installation constraint, which inverts the conventional emphasis. Four independent limits bound the usable incidence: wing stall at 15.1°, the certificated turbine temperature limit at 19.7°, the surge-critical DC60 = 0.35 threshold at 24.5°, and exhaustion of installed power at 32.2°. Incidences of 30°, 45° and 60° lie beyond every one of these limits and are reported only as off-nominal excursions. With a turbine temperature limiter representative of engine protection logic, the power available and the power required diverge beyond 19.7°, the shortfall reaching 34% at 25° and 53% at 30°, so the flight condition cannot be held at all. A sensitivity study over the ratio of local intake incidence to aircraft angle of attack shows that this ordering of limits is robust to the intake modelling, although the absolute penalties are upper bounds. A parallel hybrid-electric assist on the power turbine shaft is then modelled with a closed mass-drag-power loop covering power split, component sizing, thermal management, and the induced drag cost of the installed mass. A 10% electric share lowers interturbine temperature by 45.1 K and fuel flow by 6.83% for 41.4 kg per engine and a 5.4 kW heat rejection duty. Framed as margin recovery rather than fuel saving, an assist of only 3.8% (21.1 kW, 15.6 kg per engine) cancels the entire turbine-temperature penalty of intake distortion at 18° incidence.