Reynolds stress modelling of rectangular open-channel flow

Kang, Hyeongsik; Choi, Sung-Uk

doi:10.1002/fld.1157

Cited by 39 publications

(27 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This model has provided accurate results in many cases (see [58]) for mean-flow variables and turbulence statistics. However, the model has been found to be not completely adequate for solving certain aspects of highly anisotropic flows such as the flows in compound channels, meandering channels in which curvature effects are important, vegetated channels, and swirling flows; in those cases the RSM becomes a more accurate tool [15,16,35,59,63,75]. The RSM has been recently shown to improve also the predictions of shear stresses and some turbulence statistics in wall-bounded flows [33] and open-channel flows with vegetation [15].…”

Section: Some Recent Contributions On Turbulence Closuresmentioning

confidence: 99%

Two-phase modeling of turbulence in dilute sediment-laden, open-channel flows

Jha

Bombardelli

2009

Environ Fluid Mech

View full text Add to dashboard Cite

In this paper, we focus on assessing the performance of diverse turbulence closures in the simulation of dilute sediment-laden, open-channel flows. To that end, we base our analysis on a framework developed in a companion paper of this special issue, which puts forward a standard sediment transport model (SSTM), a partial two-fluid model (PTFM) and a complete two-fluid model (CTFM), in three-and one-dimensional (3D and 1D) versions. First, we propose in this paper extensions of the transport equations for the Reynolds stresses, and of the equations of the K-ω model to two-phase flows, starting from the general two-fluid model. We consider the drag force to be the predominant force amongst all the interactions between the two phases (water and sediment). Second, under the framework of models formed by the SSTM, the PTFM and the CTFM, we discuss simulation results obtained by employing the Reynolds stress model (RSM), the algebraic stress model (ASM), and the K-ε and the K-ω models (in their standard and extended versions), paired with each member of the framework. To assess the accuracy of the models, we compare numerical results with the experimental datasets of Vanoni, Trans ASCE 111:67-133, 1946 available data, and we provide an explanation for the variation of the Schmidt number with the ratio of the fall velocity and the wall-friction (shear) velocity. Finally, we corroborate that the Schmidt number is the key parameter to obtain satisfactory predictions of sediment transport in suspension.

show abstract

Section: Some Recent Contributions On Turbulence Closuresmentioning

confidence: 99%

Two-phase modeling of turbulence in dilute sediment-laden, open-channel flows

Jha

Bombardelli

2009

Environ Fluid Mech

View full text Add to dashboard Cite

show abstract

“…Traditional studies on flow include theoretical analysis, numerical simulation, and experimental study, and these methods have been combined and verified to solve the actual problem [19][20][21][22][23][24][25][26]. Technically, the magnitude of flow in span-wise is relatively small, which only takes up 2-5% of the main flow [27].…”

Section: Introductionmentioning

confidence: 99%

Smooth Open Channel with Increasing Aspect Ratio: Influence on Secondary Flow

Jing

Yang

Chen

2019

Water

View full text Add to dashboard Cite

A high-resolution particle image velocitmetry system is used to investigate the relationship between secondary flow and aspect ratio in a straight channel. Considering the symmetry of open channel flow, the flow parameters in half of the flume are measured. Since the variation of the aspect ratio has a direct impact on the intensity and structure of secondary flows, this study was conducted in a smooth open channel to study the influence of aspect ratio on the structure and strength of secondary flows with aspect ratio change from 3 to 7.5 under supercritical flow condition. Profiles and contour-maps of time-averaged stream-wise and vertical velocities were acquired using precise measuring instruments. The results show that there are several secondary flow cells in the cross section, and their structure affects the velocity distribution and energy distribution, which makes the velocity distribution deviate from the traditional logarithmic distribution, and the maximum velocity occur below the surface. The flow intensity of secondary flows is different under different aspect ratios. Results show great agreement with classical theory.

show abstract

“…The standard two-equation k-ε model is unable to predict secondary currents and the related velocity-dip-phenomenon since it assumes isotropic turbulence. Accurate predictions of velocity-dip-phenomena require therefore more sophisticated Reynolds-Averaged Navier Stokes (RANS) -based anisotropic turbulence models such as the Reynolds Stress Model (RSM) (Kang and Choi 2006). Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS) allow predicting secondary currents in narrow open-channels (Hayashi et al 2006).…”

Section: Introductionmentioning

confidence: 99%

An ordinary differential equation for velocity distribution and dip-phenomenon in open channel flows

Absi¹

2011

Journal of Hydraulic Research

View full text Add to dashboard Cite

International audienceAn ordinary differential equation for velocity distribution in open channel flows is presented based on an analysis of the Reynolds-Averaged Navier-Stokes equations and a log-wake modified eddy viscosity distribution. This proposed equation allows to predict the velocity-dip-phenomenon, i.e. the maximum velocity below the free surface. Two different degrees of approximations are presented, a semi-analytical solution of the proposed ordinary differential equation, i.e. the full dip-modified-log-wake law and a simple dip-modified-log-wake law. Velocity profiles of the two laws and the numerical solution of the ordinary differential equation are compared with experimental data. This study shows that the dip correction is not efficient for a small Coles' parameter, accurate predictions require larger values. The simple dip-modified-log-wake law shows reasonable agreement and seems to be an interesting tool of intermediate accuracy. The full dip-modified-log-wake law, with a parameter for dip-correction obtained from an estimation of dip positions, provides accurate velocity profiles

show abstract

Reynolds stress modelling of rectangular open-channel flow

Cited by 39 publications

References 45 publications

Two-phase modeling of turbulence in dilute sediment-laden, open-channel flows

Two-phase modeling of turbulence in dilute sediment-laden, open-channel flows

Smooth Open Channel with Increasing Aspect Ratio: Influence on Secondary Flow

An ordinary differential equation for velocity distribution and dip-phenomenon in open channel flows

Contact Info

Product

Resources

About