Idealized River Meander Using Improved Sine-Generated Curve Method

Mohamad, Irma Noorazurah; Lee, Wei-Koon; May, Raksmey

doi:10.1007/978-981-10-0155-0_13

Cited by 1 publication

(1 citation statement)

References 17 publications

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“…For the Grensmaas on the other hand, we found substantially larger water level differences which varied in the order of centimetres to decimetres. The latter findings correspond well with the case studies of Mohamad, Lee, and Raksmey (2016) and Bomers et al (2019), who both observed water level differences in the same order of magnitude. Caviedes‐Voullième et al (2012) on the other hand claimed that the numerical effects can be as influential as physical friction.…”

Section: Discussionsupporting

confidence: 91%

The effect of a local mesh refinement on hydraulic modelling of river meanders

Bilgili

Bomers

Lente³

et al. 2023

River Research & Apps

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Large-scale river models are generally discretized by relatively large mesh cells resulting in bathymetry discretization errors and numerical effects. These hydraulic models are generally calibrated by altering the bed roughness to compensate for these errors and effects. Consequently, the calibrated roughness values are mesh-dependent while generally local mesh refinements are executed after model calibration to study the effects of river interventions. This study shows both the errors caused by bathymetry discretization and numerical effects for locally refined meshes. First, schematised river meanders with a flat bed in the transverse flow direction are analysed to isolate the induced numerical effects by the mesh. Afterwards, a case study is considered to verify if similar mesh influences are found in natural river meanders.Curvilinear, triangular and hybrid (combination of curvilinear and triangular cells) meshes are used with different resolutions. The analysis shows that in the schematised river meanders lower depth-averaged flow velocities and larger water depths are simulated with coarser meshes. In the case study, substantial differences in hydrodynamics between the meshes are obtained suggesting that the bathymetry discretization is more influential than the numerical effects. Finally, it was found that triangular meshes, and rivers with narrow meander bends, are most sensitive to mesh resolution. Especially in these cases, it is desirable to refine the mesh at the desired locations before model calibration.

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Section: Discussionsupporting

confidence: 91%