Flow Statistics in the Transitional Regime of Plane Channel Flow

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.

References in corpus (14)

• Computational Study of Turbulent-Laminar Patterns in Couette Flow
• "Barber pole turbulence" in large aspect ratio Taylor-Couette flow
• A Universal Transition to Turbulence in Channel Flow
• Mean flow of turbulent-laminar patterns in plane Couette flow
• Universal continuous transition to turbulence in a planar shear flow
• Turbulent-laminar patterns in plane Poiseuille flow
• Bifurcations to turbulence in transitional channel flow
• Experimental scaling law for the sub-critical transition to turbulence in plane Poiseuille flow
• The critical point of the transition to turbulence in pipe flow
• Large scale flows in transitional plane Couette flow: a key ingredient of the spot growth mechanism
• Statistical transition to turbulence in plane channel flow
• Extended localized structures and the onset of turbulence in channel flow
• The growth mechanism of turbulent bands in channel flow at low Reynolds numbers
• Laminar-turbulent coexistence in annular Couette flow

Cited by in corpus (11)

• Linear instability of turbulent channel flow
• Direct path from turbulence to time-periodic solutions
• Patterns in transitional shear turbulence. Part 2: Emergence and optimal wavelength
• Patterns in transitional shear turbulence. Part 1. Energy transfer and mean-flow interaction
• Transitional channel flow: A minimal stochastic model
• Linear and nonlinear optimal growth mechanisms for generating turbulent bands
• Linear stability of turbulent channel flow with one-point closure
• Size-dependent transient nature of localized turbulence in transitional channel flow
• Large-scale streak instabilities of transitional channel flow
• Minimal seeds for turbulent bands
• Model for transitional turbulence in a planar shear flow