Outflow characterization of a transpiration cooled fin

Transpiration cooling is a very promising active method for thermal management of critical components for hypersonic flight. On the other side, its efficiency is affected by the characteristic of the cooling gas outflow from the porous material. This paper presents a study on the outflow characteristics of a sharp-edged, transpiration cooled fin as flown as part of the FinEx experiment of the HIFLIER1 sounding rocket. The permeable ceramic matrix composite material used for the transpiration cooled leading edge shows in general a outflow pattern dominated by single jets, distributed relatively homogeneous over the surface, disrupted by significant strong jets induced by small inhomogeneities. The general strongly anisotropic outflow characteristics were also investigated. The findings of the outflow characterization led to valuable insights for the design of future sharp-edged transpiration cooled structures.