Universality of mean velocity profile in high Re-number turbulent boundary layer

Abstract

To better understand high Reynolds number zero-pressure-gradient turbulent boundary layers detailed hot-wire measurements of the mean and fluctuating streamwise velocity are made in RTRI ’s low-noise wind tunnel in Maibara Japan. The momentum thickness Reynolds number is up to approximately 8×104. Using the friction velocity measured by oil film interferometry, mean velocity profile shows a clear log-law region. The turbulent intensity profile also shows the log-law scaling predicted by attached eddy model. However, the log-regions of mean and turbulent intensity do not match with each other. Kármán constant κ, additive constant B, and wake parameter Π are evaluated as 〈κ〉 = 0.385 ± 0.003, 〈B〉 = 4.26 ± 0.15, 〈B1〉 = −1.077 ± 0.089, 〈Π〉 = 0.455 ± 0.025, and they relate closely with each other by simple equation.

Keywords

• turbulent boundary layer
• mean velocity profile
• high reynolds-number universality