A study on the influence of triggering pipe flow regarding mean and higher order statistics

The evolution of statistical pipe flow quantities, such as the turbulence intensity, the skewness and the flatness, are investigated to clarify, hich development length is needed, until the state of fully developed turbulence is achieved. This observations take place in a relatively large pipe test facility with an inner pipe diameter of Di 0.19 m and a total length of L 27 m. The reached Reynolds number range is 1.5 · 105 ≤ Rem ≤ 8.5 · 105. To quantify the mean and fluctuating velocity as well as the depending statistical quantities, the constant temperature hot-wire anemometry is applied. Through these intensive centerline measurements we observe a development length of L 70 D, to ensure a fully developed turbulent flow state.