Research on the Effect of Front Variable Area Bypass Injector Modulation on the Adaptive Cycle Engine Performance Based on Multi-fidelity Simulation

In this paper, two types of Front Variable Area Bypass Injector (FVABI) Computational Fluid Dynamics (CFD) models for axial type and rotary type are established and their operating characteristics are generated. The performance of the two types of FVABI under two operating modes is compared considering the Adaptive Cycle Engine (ACE) matching requirements. A multi-fidelity simulation model is established based on the coupling calculation of the 2-D FVABI and 0-D ACE performance model. A throttling performance control law design method is proposed based on fitting multiple data points. The effects of different modulation settings of the FVABI on the optimum control law and performance of the ACE under various operating conditions are simulated and analyzed. Simulation results indicate that, with the same mass flow modulation capacity, the axial type FVABI could realize equal or higher total pressure recovery coefficients in both ACE operation modes. Considering the collaborative modulation of other ACE components, the different FVABI modulation states could result in up to a 3.2% reduction in maximum thrust in the intermediate conditions. For the ACE constant inlet airflow throttling performance, the FVABI modulation could reduce the Specific Fuel Consumption rate (SFC) by 2% and 1.3% in the deep throttling intervals in subsonic and supersonic cruise conditions, respectively. The FVABI modulation has less effect (relative difference less than 0.2%) on SFC in the non-deep throttling interval of the throttling process.