Flow Statistics in the Transitional Regime of Plane Channel Flow

Flow Statistics in the Transitional Regime of Plane Channel Flow

Pavan V. Kashyap, Yohann Duguet and Olivier Dauchot

Abstract

The transitional regime of plane channel flow is investigated above the transitional point below which turbulence is not sustained, using direct numerical simulation in large domains. Statistics of laminar-turbulent spatio-temporal intermittency are reported. The geometry of the pattern is first characterized, including statistics for the angles of the laminar-turbulent stripes observed in this regime, with a comparison to experiments. High-order statistics of the local and instantaneous bulk velocity, wall shear stress and turbulent kinetic energy are then provided. The distributions of the two former quantities have non-trivial shapes, characterized by a large kurtosis and/or skewness. Interestingly, we observe a strong linear correlation between their kurtosis and their skewness squared, which is usually reported at much higher Reynolds number in the fully turbulent regime. View Full-Text

Keywords: transition to turbulence; spatio-temporal intermittency; channel flow

Full Paper can be downloaded at: https://www.mdpi.com/1099-4300/22/9/1001

This article belongs to the Special Issue Intermittency in Transitional Shear Flows

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