Comparação entre a aproximação hidrostática e a não-hidrostática na simulação numérica de escoamentos com superfície livre / Comparison between hydrostatic and non-hydrostatic pressure approximation in free surface flow nu

Monteiro, Leonardo; Schettini, Edith Beatriz Camaño

doi:10.21168/rbrh.v20n4.p1051-1062

Cited by 2 publications

(8 citation statements)

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“…In summary, the quadratic solution was better in interacting with uneven bottoms to represent complex nonlinear wave simulations. Similar results to the quadratic interpolation solution were reported by Chen [3], Walters [18], Dingemans [47], Cui et al [53], and Monteiro and Schettini [20].…”

Section: Wave Propagation Over a Submerged Barsupporting

confidence: 87%

“…The quadratic results show best performance between methods (Bias of 0.18 mm and KGE of 0.87, see Table 1), indicating best agreement with the analytical solution, despite similar RMSE and NSE found in the other methods. The phase representation showed good agreement with the analytical solution for all tested methods, showing a cumulative phase error of only 0.3 s at the end of the simulation, which is similar to previous studies [20,48]. As expected, the simulation neglecting the convective terms had a shorter computation time (~1.65 s) than the bilinear (~2.23 s) and quadratic interpolations (~2.37 s).…”

Section: D Standing Waves In a Closed Basinsupporting

confidence: 87%

“…Standing waves in a three-dimensional closed basin: this test case verifies the capability of the model to simulate 3D linear waves, including phase and amplitude representation [6,20,48]. The motion in the basin is caused only by the initial condition of the free surface.…”

supporting

confidence: 58%

“…In the no-advection scheme, u * , v * , and w * (Equations (17) and (18)) were set directly equal to the horizontal and vertical face velocities. The numeric experiment set-up [6,20,48] are a closed cubic basin with edge of 10 m and wave amplitude set to 0.1 m (Figure 4). The spatial domain was discretized using a regular grid with 0.5 m resolution, resulting in 8000 computation cells.…”

Section: D Standing Waves In a Closed Basinmentioning

confidence: 99%

“…The Eulerian-Lagrangian Method (ELM) is one of the most popular and accurate techniques used to numerically solve the advection terms in RANS and solute transport equations [7,8,[13][14][15][16][17][18][19][20]. The purpose of ELM is to combine the simplicity of the fixed Eulerian computational grid with a stable and accurate Lagrangian approach.…”

Section: Introductionmentioning

confidence: 99%

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Combined Use of High-Resolution Numerical Schemes to Reduce Numerical Diffusion in Coupled Nonhydrostatic Hydrodynamic and Solute Transport Model

Cunha

Fragoso

Tavares

et al. 2019

Water

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In three-dimensional simulations of free-surface flow where the vertical velocities are relevant, such as in lakes, estuaries, reservoirs, and coastal zones, a nonhydrostatic hydrodynamic approach may be necessary. Although the nonhydrostatic hydrodynamic approach improves the physical representation of pressure, acceleration and velocity fields, it is not free of numerical diffusion. This numerical issue stems from the numerical solution employed in the advection and diffusion terms of the Reynolds-averaged Navier–Stokes (RANS) and solute transport equations. The combined use of high-resolution schemes in coupled nonhydrostatic hydrodynamic and solute transport models is a promising alternative to minimize these numerical issues and determine the relationship between numerical diffusion in the two solutions. We evaluated the numerical diffusion in three numerical experiments, for different purposes: The first two experiments evaluated the potential for reducing numerical diffusion in a nonhydrostatic hydrodynamic solution, by applying a quadratic interpolator over a Bilinear, applied in the Eulerian–Lagrangian method (ELM) step-ii interpolation, and the capability of representing the propagation of complex waves. The third experiment evaluated the effect on numerical diffusion of using flux-limiter schemes over a first-order Upwind in solute transport solution, combined with the interpolation methods applied in a coupled hydrodynamic and solute transport model. The high-resolution methods were able to substantially reduce the numerical diffusion in a solute transport problem. This exercise showed that the numerical diffusion of a nonhydrostatic hydrodynamic solution has a major influence on the ability of the model to simulate stratified internal waves, indicating that high-resolution methods must be implemented in the numerical solution to properly simulate real situations.

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Section: Wave Propagation Over a Submerged Barsupporting

confidence: 87%

Section: D Standing Waves In a Closed Basinsupporting

confidence: 87%

supporting

confidence: 58%

Section: D Standing Waves In a Closed Basinmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Combined Use of High-Resolution Numerical Schemes to Reduce Numerical Diffusion in Coupled Nonhydrostatic Hydrodynamic and Solute Transport Model

Cunha

Fragoso

Tavares

et al. 2019

Water

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Improvement of Non-Hydrostatic Hydrodynamic Solution Using a Novel Free-Surface Boundary Condition

Cunha

Fragoso

Chalegre

et al. 2020

Water

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Hydrodynamic models based on the RANS equation are well-established tools to simulate three-dimensional free surface flows in large aquatic ecosystems. However, when the ratio of vertical to horizontal motion scales is not small, a non-hydrostatic approximation is needed to represent these processes accurately. Increasing efforts have been made to improve the efficiency of non-hydrostatic hydrodynamic models, but these improvements require higher implementation and computational costs. In this paper, we proposed a novel free-surface boundary condition based on a fictional sublayer at the free-surface (FSFS). We applied the FSFS approach at a finite difference numerical discretization with a fractional step framework, which uses a Neumann type of boundary condition to apply a hydrostatic relation in the top layer. To evaluate the model performance, we compared the Classic Boundary Condition Approach (CBA) and the FSFS approach using two numerical experiments. The experiments tested the model’s phase error, capability in solving wave celerity and simulate non-linear wave propagation under different vertical resolution scenarios. Our results showed that the FSFS approach had a lower phase error (2 to 5 times smaller) than CBA with a little additional computational cost (ca. 7% higher). Moreover, it can better represent wave celerity and frequency dispersion with 2 times fewer layers and low mean computational cost (CBA δ t = 2.62 s and FSFS δ t = 1.22 s).

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Comparação entre a aproximação hidrostática e a não-hidrostática na simulação numérica de escoamentos com superfície livre / Comparison between hydrostatic and non-hydrostatic pressure approximation in free surface flow nu

Cited by 2 publications

References 0 publications

Combined Use of High-Resolution Numerical Schemes to Reduce Numerical Diffusion in Coupled Nonhydrostatic Hydrodynamic and Solute Transport Model

Combined Use of High-Resolution Numerical Schemes to Reduce Numerical Diffusion in Coupled Nonhydrostatic Hydrodynamic and Solute Transport Model

Improvement of Non-Hydrostatic Hydrodynamic Solution Using a Novel Free-Surface Boundary Condition

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