Static pressure measurement error for wall taps with high Reynolds number turbulent pipe flow

An experimental study on a static pressure measurement errors in wall taps was conducted using a high Reynolds number actual flow facility (Hi-Reff). The bulk Reynolds number Re_D examined was up to 1.3 × 10⁷ and tap Reynolds number Re_t was up to 8.5 × 10⁴. The behavior of the static pressure measurement error at high Reynolds numbers was clarified experimentally. The static pressure measurement error normalized by wall shear stress increases with Reynolds number and reaches an asymptotic value. Its maximum value is 7.1 at Re_t = 8470. The asymptotic value increases with the size of the tap diameter up to 6 mm and then becomes constant for tap diameters exceeding 6 mm. The universal curve reported in previous studies is observed for only a limited range of tap Reynolds numbers of below 700 and of tap diameters below 4 mm.