Preliminary Cold-Flow Aerodynamic Assessment of the F100-PW-229 Annular Combustor
Preliminary aerodynamic assessment provides an efficient means of investigating internal flow organization in aircraft gas turbine combustors before more computationally demanding three-dimensional and reactive-flow simulations are undertaken. This study presents a preliminary CFD investigation of cold-flow phenomena in the annular combustion chamber of the F100-PW-229 low-bypass turbofan engine. A two-dimensional planar model was intentionally adopted to identify dominant flow structures and assess their response to representative engine operating conditions at reduced computational cost. Numerical simulations were performed in ANSYS Fluent using a pressure-based coupled solver and the k-ω SST turbulence model for idle, cruise, and maximum rotational speed conditions. Additional simulations were performed at cruise conditions for an altitude of 11 km to examine the influence of reduced ambient pressure and air density on the internal flow field. The results show that increasing engine rotational speed primarily changes the intensity of the aerodynamic field while preserving its dominant spatial organization. The maximum velocity at idle was approximately 55% lower than that at maximum rotational speed, while the corresponding value at cruise was 20.1% lower. Similarly, the maximum stagnation pressure at idle was approximately 67.1% lower than that at maximum rotational speed, while the difference between cruise and maximum speed was 24.2%. A distinct vortex structure was identified in the outer annular passage between the liner and casing, with its location shifting downstream as the operating condition changed. At 11 km altitude, the calculated pressure level was approximately 81% lower and the characteristic flow velocity approximately 9% lower than under corresponding ground-level conditions, while the dominant flow topology remained similar. These results highlight the role of combustor geometry and secondary-air distribution in governing global pressure redistribution, velocity development, and recirculation behavior. Within the scope of the adopted two-dimensional non-reacting formulation, the obtained flow patterns provide an initial aerodynamic reference for identifying regions of interest for subsequent high-fidelity simulations. The proposed approach is therefore intended as a computationally efficient preliminary engineering tool rather than a substitute for validated three-dimensional combustor modelling.