Comparative Analysis of Porous Bleed Simulation Techniques: From Porous Wall Boundary Condition to Automatic Mesh Refinement

This paper presents different numerical frameworks for simulating porous bleed systems. Despite progress in turbulence modelling and increased CPU resources, simulating such systems remains challenging, particularly for compressible turbulent flows, due to the significant scale disparity between the perforation holes and the main flow features. This study aims to evaluate four different methods to predict porous bleed effects on a supersonic air intake, with applications to industrial needs such as airbreathing cruise missile or combat aircraft design. The investigated approaches necessitate various levels of meshing effort, engineering time, computational resources and physical modelling. The four approaches are namely: (1) state-of-the-art bleed model, based on continuous suction, (2) classical multi-block structured body-fitted simulations where the holes are meshed (considered as reference), (3) IBC-based approach, which alleviates the need to mesh manually every hole, and (4) automatic mesh refinement, which allows for fully automated body-fitted workflow with minimal engineering time. A thorough comparison of quantities of significance for porous bleeds, like flow structure, bleed mass flux and velocity profiles, is undertaken. Despite a fair overall prediction capability, the porous bleed model approach suffers from the most significant discrepancies with respect to the reference data.