Physical And Numerical Investigation of the Skimming Flow Over a Stepped Spillway

Carvalho, Rita F.; Amador, António

doi:10.1007/978-3-540-89465-0_304

Cited by 11 publications

(7 citation statements)

References 3 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A detailed analysis of the above contributions for stepped spillways is presented in Table 1, revealing the following features/issues: (i) The comparisons between numerical and experimental results in those papers have been mostly of qualitative nature; Issues with the measurements in the aerated region [86] Cheng et al [30,31] (ii) whereas Chen et al [29] (see also Yasuda et al [86]), Cheng et al [30,31] and Arantes [5] solved the flows of water and air altogether (which was defined as Partial Volume-of-Fluid (VoF) method in Bombardelli et al [16]), Tabbara et al [79] employed a numerical strategy based on re-meshing each time step. In turn, Carvalho and Amador [23] used a purported VoF method, but they did not report comparisons of numerical results with data of the location of the free surface; (iii) some of the simulations have been developed using unstructured grids with good resolution near the walls but with a lower resolution near the free surface; (iv) only the papers by Cheng et al [30,31] and Carvalho and Amador [23] include discussions on the distribution of turbulence statistics in the steps through contours of the turbulent kinetic energy (TKE) obtained numerically; (v) experimental data obtained in some papers to validate the numerical simulations corresponded to relatively small facilities with potential significant scale effects; (vi) to the best of our knowledge, very few numerical analyses of the non-aerated flow region which present and discuss comprehensive comparisons of computational results with data have been published in reputed peer-reviewed literature. Thus, more work is needed to understand completely the flow.…”

Section: Introductionmentioning

confidence: 97%

“…Empirical models have been developed for predicting the main air-water flow properties along the chute by Hager and Boes [45], Matos [57], Chanson [25], Boes and Hager [9,10], Meireles [65], Renna [71] and Ohtsu et al [67]. In spite of this considerable number of studies, and to the best of our knowledge, only Amador [2], Amador et al [3], Meireles et al [65], Gonzalez and Chanson [43], Carvalho and Amador [23] and Meireles and Matos [64] have focused on the flow properties of the non-aerated flow region of stepped spillways.…”

Section: Introductionmentioning

confidence: 99%

“…A small number of simulations of the skimming flow over stepped spillways have been communicated very recently [5,23,[29][30][31]79], describing both the aerated and non-aerated flow regions. A detailed analysis of the above contributions for stepped spillways is presented in Table 1, revealing the following features/issues: (i) The comparisons between numerical and experimental results in those papers have been mostly of qualitative nature; Issues with the measurements in the aerated region [86] Cheng et al [30,31] (ii) whereas Chen et al [29] (see also Yasuda et al [86]), Cheng et al [30,31] and Arantes [5] solved the flows of water and air altogether (which was defined as Partial Volume-of-Fluid (VoF) method in Bombardelli et al [16]), Tabbara et al [79] employed a numerical strategy based on re-meshing each time step.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Laboratory measurements and multi-block numerical simulations of the mean flow and turbulence in the non-aerated skimming flow region of steep stepped spillways

2010

View full text Add to dashboard Cite

We present and discuss the results of a comprehensive study addressing the non-aerated region of the skimming flow in steep stepped spillways. Although flows in stepped spillways are usually characterized by high air concentrations concomitant with high rates of energy dissipation, the non-aerated region becomes important in small dams and/or spillways with high specific discharges. A relatively large physical model of such spillway was used to acquire data on flow velocities and water levels and, then, well-resolved numerical simulations were performed with a commercial code to reproduce those experimental conditions. The numerical runs benefited from the ability of using multi-block grids in a Cartesian coordinate system, from capturing the free surface with the TruVOF method embedded in the code, and from the use of two turbulence models: the k−ε and the RNG k−ε models. Numerical results are in good agreement with the experimental data corresponding to three volumetric flow rates in terms of the time-averaged velocities measured at diverse steps in the spillway, and they are in very satisfactory agreement for water levels along the spillway. In addition, the numerical results provide information on the turbulence statistics of the flow. This work also discusses important aspects of the flow, such as the values of the exponents of the power-law velocity profiles, and the characteristics of the development of the boundary layer in the spillway.

show abstract

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Laboratory measurements and multi-block numerical simulations of the mean flow and turbulence in the non-aerated skimming flow region of steep stepped spillways

2010

View full text Add to dashboard Cite

show abstract

“…The quantity of studies dealing with the non-aerated part of the flow is limited (Amador, 2005;Amador et al, 2006;Bombardelli et al, 2011;Carvalho & Amador, 2009;Hunt & Kadavy, 2010;Meireles & Matos, 2009;Toro et al, 2016;Zhang & Chanson, 2016a, 2016b. This fact is to a certain extent justified, as on most prototype applications self-aeration would occur in a considerable portion of the chute for the design discharge.…”

Section: Introductionmentioning

confidence: 99%

Influence of VOF technique, turbulence model and discretization scheme on the numerical simulation of the non-aerated, skimming flow in stepped spillways

Bayón

Toro

Bombardelli

et al. 2018

Journal of Hydro-environment Research

View full text Add to dashboard Cite

An accurate description of the hydrodynamics in the non-aerated region of the skimming flow on stepped spillways is of outmost importance, particularly in small structures at large discharges. In addition, the flow features upstream of the inception point of air entrainment determine the flow behavior in the downstream self-aerated region. In this work, numerical models of the flow in the non-aerated region of stepped spillways have been developed using diverse turbulence closures and discretization schemes implemented in two CFD codes: OpenFOAM and FLOW-3D ®. Partial VOF (Volume of Fluid) and "True" VOF (TruVOF) approaches are employed to capture the position of the free surface. The Standard, RNG and Realizable k-ε, in addition to the SST k-ω

show abstract

“…A revised plan was formulated and the appropriate amended design was examined using numerical modelling. Carvalho and Amador (2009) [7] also simulated the flow in the nonaerated region by using the FLOW-3D with the FDM. Their numerical results were compared with the physical data and found a good agreement in the non-aerated region.…”

Section: Methodsmentioning

confidence: 99%

Application of Numerical Methods in Design of Hydraulic Structures

Rad¹

2016

Communications on Advanced Computational Science with Applicati

View full text Add to dashboard Cite

This study was aimed to evaluate the use of numerical methods in the design of hydraulic structures and use a numerical model to validate the simulation of flow over three types of spillway which are: smooth spillway, various of step spillway, labyrinth spillway and side spillway. Numerical methods can assist in the design of hydraulic structures in the evaluation of the energy loss, calculated discharge coefficient and cavitation phenomena investigated by examining the pressure field and flow field. Designers are challenged to use numerical methods for the design of hydraulic structures due to the complexity of the specific flow field of hydraulic structures, such as the free surface flow, two-phase and multi-phase flows, turbulent flow and turbulence. In this study provide the best and efficient numerical methods for the numerical modeling of hydraulic structures, which are obtained by various researchers who have conducted research studies on numerical methods. Using the guidelines presented in this study can help designers in numerical modeling of hydraulic structures that are under all the facts and reliable models apply the results of the numerical method.Computational Fluid Dynamics (CFD) is a type of numerical model that can be used to solve problems involving fluid flow. CFD can provide a significant amount of computation time and more economical solution than a physical model. The fundamental principles for all numerical models are similar. Problems can be described, physically, by a set of partial differential equations. Then, a numerical method is used to formulate a set of algebraic equations that represent the partial differential equations.

show abstract

Physical And Numerical Investigation of the Skimming Flow Over a Stepped Spillway

Cited by 11 publications

References 3 publications

Laboratory measurements and multi-block numerical simulations of the mean flow and turbulence in the non-aerated skimming flow region of steep stepped spillways

Laboratory measurements and multi-block numerical simulations of the mean flow and turbulence in the non-aerated skimming flow region of steep stepped spillways

Influence of VOF technique, turbulence model and discretization scheme on the numerical simulation of the non-aerated, skimming flow in stepped spillways

Application of Numerical Methods in Design of Hydraulic Structures

Contact Info

Product

Resources

About