Evaluation of hot-wire probe performance for turbulence measurement: a priori error analysis based on stereoscopic PIV
Résumé
The present study considers a generic cross hot-wire probe (XHWA) employed to measure both the longitudinal and the vertical velocity component in a high Reynolds number boundary layer developing over a staggered cube array. Stereoscopic PIV measurements performed in a vertical plane are used as input in the equations for the effective cooling velocities of the two wires used to simulate the XHWA measurements and estimate its performance. The influence of both the wire angle and the role of the non-measured third component are investigated. A consistent underestimation of the velocity variances and the Reynolds shear-stress is reported, the wall-normal component being the most affected. For a 45° probe, it is shown that the non-measured component is responsible for this underestimation that reaches almost 20% just above the roughness elements.