Positive surge propagating in an asymmetrical canal

Kiri, Urvisha; Leng, Xinqian; Chanson, Hubert

doi:10.1016/j.jher.2020.04.002

Cited by 4 publications

(8 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Next to the free-surface, the velocity fluctuations showed a gradual increase following the passage of the bore but with a less clearly observable peak. A similar trend was observed for the vertical and transverse velocity fluctuations, but with lower magnitude (KIRI et al 2018 Across the channel width, the fluctuation in velocity components increased in magnitude towards the shallow-water section. For all results, the peak in velocity fluctuations occurred next the bed shortly after the passage of the bore front, rather than at the greatest rate of change in the free-surface elevation.…”

Section: Discussionsupporting

confidence: 78%

“…The results (Eq. ( 10)) were in close agreement with the discharge measurements within 3.5% (KIRI et al 2018). The velocity contour plots showed that the velocity was not uniformly distributed.…”

Section: Steady Open Channel Flow Propertiessupporting

confidence: 83%

“…Quantitatively, shear stress amplitude |(v i v j ) 50 | in excess of 40 Pa and shear stress fluctuations (v i v j ) 75-25 larger than 150 Pa were recorded in the present study. Such values of median shear stress magnitudes were one to two orders of magnitude larger than boundary shear stress levels in steady flow conditions (KIRI et al 2018) and steady flow measurements in compound channels (e.g. MACINTOSH 1990).…”

Section: Transient Secondary Motion and Shear Planementioning

confidence: 79%

“…The unsteady free-surface water elevations were recorded using non-intrusive acoustic displacement meters The ADV signals were post-processed in steady flows (KIRI et al 2018). The unsteady velocity measurements were not post-processed, behind a careful synchronisation for ensemble-averaging.…”

Section: Experimental Facility and Instrumentationmentioning

confidence: 99%

See 3 more Smart Citations

Transient secondary currents behind a compression wave in an irregular channel

2020

Self Cite

View full text Add to dashboard Cite

A compression wave is an unsteady rapidly-varied open channel flow motion, characterised by an increase in water depth. A detailed investigation was conducted in a prismatic asymmetrical channel, to better understand the physical processes observed in tidal/tsunami-bore affected estuaries with irregular topography. The prismatic channel was equipped with a 1V:5H transverse slope across the full channel width. The free-surface data presented three-dimensional unsteady flow features, and the velocity measurements showed a drastic impact of the surge on the flow field, with strong three-dimensional features.With the arrival of the surge front, the transverse velocity component became large in the shallow-water section, indicating some unsteady secondary motion and recirculation during and shortly after the passage of the surge. The Reynolds shear stress data were associated with large turbulent stresses and shear stress fluctuations. For d 1 /D < 1, both velocity and shear stress data showed a transient longitudinal x-z shear plane, about y/W  0.5-0.6, with conjugate transverse flow reversal for 0.5-0.6 < y/W < 1. In the transient shear plane, high Reynolds stress magnitudes and shear stress fluctuations were observed behind the surge front, up to one to two orders of magnitude larger than boundary shear stress levels observed in steady flows in compound channels.

show abstract

Section: Discussionsupporting

confidence: 78%

Section: Steady Open Channel Flow Propertiessupporting

confidence: 83%

Section: Transient Secondary Motion and Shear Planementioning

confidence: 79%

Section: Experimental Facility and Instrumentationmentioning

confidence: 99%

See 2 more Smart Citations

Transient secondary currents behind a compression wave in an irregular channel

2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although Rodriguez-Diaz first considered the hydraulic jump formed in an asymmetrical trapezoidal channel [17], Kiri et al [21], Fig. 2 conducted a new series of tests on this type of cross-section after over half a century.…”

Section: Introductionmentioning

confidence: 99%

Study of a Hydraulic Jump in an Asymmetric Trapezoidal Channel with Different Sluice Gates

Debabeche,

Cherhabil

2024

FDMP

View full text Add to dashboard Cite

In this study, the main properties of the hydraulic jump in an asymmetric trapezoidal flume are analyzed experimentally, including the so-called sequent depths, characteristic lengths, and efficiency. In particular, an asymmetric trapezoidal flume with a length of 7 m and a width of 0.304 m is considered, with the bottom of the flume transversely inclined at an angle of m = 0.296 and vertical lateral sides. The corresponding inflow Froude number is allowed to range in the interval (1.40 < F1 < 6.11). The properties of this jump are compared to those of hydraulic jumps in channels with other types of cross-sections. A relationship for calculating hydraulic jump efficiency is proposed for the considered flume. For F1 > 5, the hydraulic jump is found to be more effective than that occurring in triangular and symmetric trapezoidal channels. Also, when

show abstract

Hydrodynamic shock in Rivers: Physical and numerical modeling of flow structures in tsunami-like bores

Simon,

Lubin,

Chanson

2023

Physics of Fluids

View full text Add to dashboard Cite

The aim of this work is to provide convincing evidence on the turbulent processes induced by three-dimensional (3D) bores, based on physical and computational fluid dynamics studies of undular tidal bores, a phenomenon very similar to a tsunami-like bore propagating inland along a river. The numerical study is performed by solving the Navier–Stokes equations with a large eddy simulation method in order to access the turbulent flow evolution during the bore passage. Two- and three-dimensional simulations are performed with and without turbulence before bore generations to inspect the effect of coherent structures on the bore propagation. A complex three-dimensional flow takes place during the bore passage. Beneath the undulation crests, a strong shear is observed near the channel bed. Moreover, ejection of turbulent structures occurs during the propagation of undular bores depending on the initial flow conditions. These simulations provide the first detailed three-dimensional data of undular bores intricate flow structure. The results showed that the propagation of the bore front drastically changes the properties of the water column. It is also highlighted that for an upstream current exceeding a threshold value, near-bed eddies are generated and ejected in the water column independently of the free surface characteristics. Our simulations improve the understanding of positive surges which could be extended to tsunami-like bores studies.

show abstract

Positive surge propagating in an asymmetrical canal

Cited by 4 publications

References 18 publications

Transient secondary currents behind a compression wave in an irregular channel

Transient secondary currents behind a compression wave in an irregular channel

Study of a Hydraulic Jump in an Asymmetric Trapezoidal Channel with Different Sluice Gates

Hydrodynamic shock in Rivers: Physical and numerical modeling of flow structures in tsunami-like bores

Contact Info

Product

Resources

About