Laminar separation bubble analysis by means of single–shot lifetime temperature sensitive paint in a water towing tank

A laminar separation bubble is studied on an SD7003 foil in a water towing tank at a Reynolds number of <?CDATA 6·10⁴?> 6 ⋅ 10 4 and an angle of attack of 6 ∘ by means of the temperature sensitive paint single-shot lifetime method in order to resolve the footprints and dynamics of vortical structures at low inflow turbulence levels. A heat flux is created by applying a carbon based heating layer on the suction side of the foil. The influence of the surface heating on the transition behaviour is analyzed using 2D2C-PIV and found to be negligible. The results demonstrate the capability of the single-shot lifetime method to quantify salient time-averaged flow characteristics, as well as to resolve and characterize the footprints of the dominant coherent structures.