The impact of a multilevel protection column on the propagation of a water wave and pressure distribution during a dam break: Numerical simulation

2021 ◽  
Vol 598 ◽  
pp. 126212 ◽  
Author(s):  
Alibek Issakhov ◽  
Aliya Borsikbayeva
Keyword(s):  
Numerical Simulation ◽  
Pressure Distribution ◽  
Water Wave ◽  
Dam Break ◽  
The Impact

scholarly journals Coupled DEM-SPH Method for Interaction between Dilated Polyhedral Particles and Fluid

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Shunying Ji ◽  
Xiaodong Chen ◽  
Lu Liu
Keyword(s):  
Numerical Simulation ◽  
Parallel Algorithm ◽  
Granular Materials ◽  
Computational Efficiency ◽  
Dam Break ◽  
Solid Interface ◽  
Fluid Media ◽  
Complex Fluid ◽  
Simulation Results ◽  
The Impact

The discrete element method (DEM) and smoothed particle hydrodynamics (SPH) can be adopted to simulate the granular materials and fluid media respectively. The DEM-SPH coupling algorithm can be developed for the dynamic interaction between the two media. When the particle material is simulated by polyhedral element, a fluid-solid coupling interface would lead to the complex geometry between the granular particle and the fluid. The boundary particle method is traditionally used for the fluid-solid interface but with low computational efficiency. In this paper, the dilated polyhedral element is constructed based on Minkowski sum theory, while the contact force between the elements is calculated by Hertzian contact model. Accordingly the dilated polyhedra based DEM is established. The weakly compressible SPH is adopted to simulate the fluid medium, while the interaction on the geometrically complex fluid-solid interface is evaluated with the repulsive force model which can be determined by the contact detection between SPH particles and solid particles in geometry. This method avoids the storage and calculation of a large number of boundary particles, which can be potentially applied for the complex fluid-solid boundary. In order to improve the computational efficiency, a GPU-based parallel algorithm is employed to achieve high performance computation of SPH. The acceleration of the parallel algorithm is evaluated by the cases of dam break. The numerical simulation of the impact of dam break on cubes is implemented. The simulation results are verified with the corresponding experimental and simulation results. Therefore, the rationality and accuracy of the DEM-SPH coupling method for numerical simulation of the interaction between granular materials and fluid media are illustrated. This method is then adopted for the impact of falling rocks on underwater pipeline. The force of water and rocks on the pipeline is analyzed. This method can be further applied for real engineering problems.

Numerical Simulation of High Velocity Waterjet Characteristics and Impact Pressure

2011 ◽  
Vol 109 ◽  
pp. 551-556 ◽  
Author(s):  
Qun Luo ◽  
Kai He ◽  
He Mao ◽  
Jiu Hua Li ◽  
Quan Chang Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Pressure Distribution ◽  
High Velocity ◽  
Impact Pressure ◽  
Hydrodynamic Characteristics ◽  
Initial Region ◽  
Mixture Flow ◽  
Incremental Sheet Metal Forming ◽  
Pump Pressure ◽  
The Impact

This paper presents a numerical simulation approach to analyze high velocity waterjet characteristics and impact pressure. For the complexity of waterjet formation in air, multiphase mixture flow model is used, and the simulation is performed in FLUNET software. The simulation includes the hydrodynamic characteristics and pressure distribution of high velocity waterjet in air. The decay of pressure at different distance along centerline under different pump pressure is analyzed and the length of the initial region of waterjet is determined. In addition, the impact pressure of waterjet at different stand-off distance is also simulated, and the impact pressure distribution and its changing tendency with the stand-off distance are obtained. This paper provides theoretical parameters for waterjet incremental sheet metal forming.

Numerical simulation of dam-break mudflow based on the Herschel-Bulkley model

2021 ◽  
Author(s):  
jinbo Tang ◽  
Peng Cui ◽  
Jiangang Chen
Keyword(s):  
Numerical Simulation ◽  
Numerical Model ◽  
Laboratory Experiments ◽  
Fine Particles ◽  
Shear Thinning ◽  
Numerical Results ◽  
Dam Break ◽  
Navier Stokes Equation ◽  
Study Laboratory ◽  
The Impact

<p>Mudflow behaves normally the flowing properties of viscoplastic or pseudo-plastic stemming from flocculent network structures formed by fine particles within the mud. In order to obtain the dynamical characteristics of the dam-break of mudflow, a numerical model has been developed in the present study. The numerical model solved the Navier-Stokes equation with the Herschel-Bulkley model, which exhibits a plastic properties of fluid with shear-thinning. The two-step projection method are employed to solve the velocity field in present numerical model, and the Bi-CGSTAB technique are implemented to solve the pressure Poisson equation. The volume of fluid (VOF) method is used to track the broken the free surface. In this study, the numerical simulation of dam-break with Herschel-Bulkley fluid are implemented, the numerical results agree well with the other numerical results. Furthermore, when the shear-thinning index is equals to unity, the Herschel-Bulkley model becomes Bingham model. In this study, laboratory experiments of dam-break of slurry in the flume have been conducted to record data with time of the surface height of mudflow and pressure in the bottom of flume. The same cases with laboratory experiments are implemented in our numerical model, the numerical results match with the laboratory experiments. Finally, as a demonstration, the impact of mudflow on the structures   are simulated and discussed.</p>

Influence of the Distribution of Dual Cascades on Double Vanes Based on the Solid-Liquid Two-Phase Flow

2015 ◽  
Vol 723 ◽  
pp. 186-189
Author(s):  
Fu Chun Liu ◽  
Jian Rong Zhang ◽  
Dong Wang
Keyword(s):  
Numerical Simulation ◽  
Pressure Distribution ◽  
Velocity Vector ◽  
Active Surface ◽  
Energy Performance ◽  
Phase Flow ◽  
Two Phase ◽  
Guide Vanes ◽  
Solid Liquid ◽  
The Impact

The relative positional relationship between the stay vanes and guide vanes is researched to analyze the impact on the hydraulic performance of the Turbine based on N-S equations and RNG k-ε turbulence model under the conditions of sandy water with the numerical simulation method.There are main five kinds of the relative positional relationship between the dual cascades is used to analyse the trends of the distribution about the pressure and velocity. The relative circumferential positions between the dual cascades have obviously effect on the flow verified.And the velocity vector and the pressure distribution on the surface of the guide vanes are studied further.The results show that energy performance is best if little circumferential position differences between the dual cascades in two typical conditions.However, thedistribution about the pressure and velocity is uneven on the active surface of guide vanes, exacerbating the local abrasion of the vanes.

Field Observation and Simulation of Sediment Resuspension in a Shallow Lake

1988 ◽  
Vol 20 (6-7) ◽  
pp. 263-270 ◽  
Author(s):  
K. Otsubo ◽  
K. Muraoka
Keyword(s):  
Numerical Simulation ◽  
Shallow Lake ◽  
Water Wave ◽  
Field Data ◽  
Sediment Resuspension ◽  
Field Research ◽  
Lake Kasumigaura ◽  
Bed Erosion ◽  
Current Water ◽  
Good Agreement

The dispersion and resuspension of sediments in Takahamairi Bay basin of Lake Kasumigaura were studied by means of field research and numerical simulation. The field data on wind direction and velocity, lake current, water wave, and turbidity were shown. Based on these results, we discuss how precipitated sediments were resuspended in this shallow lake. To predict the turbidity and the depth of bed erosion, a simulation model was established for this lake. The calculated turbidity showed good agreement with the field data. According to the simulated results, the turbidity reaches 200 ppm, and the bed is eroded several millimeters deep when the wind velocity exceeds 12 m/s in the lake.

scholarly journals Influence of the Spatial Pressure Distribution of Breaking Wave Loading on the Dynamic Response of Wolf Rock Lighthouse

2021 ◽  
Vol 9 (1) ◽  
pp. 55
Author(s):  
Darshana T. Dassanayake ◽  
Alessandro Antonini ◽  
Athanasios Pappas ◽  
Alison Raby ◽  
James Mark William Brownjohn ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Pressure Distribution ◽  
Distinct Element ◽  
Breaking Waves ◽  
Breaking Wave ◽  
Wave Loading ◽  
Wave Impact ◽  
Pressure Distributions ◽  
Impact Area ◽  
The Impact

The survivability analysis of offshore rock lighthouses requires several assumptions of the pressure distribution due to the breaking wave loading (Raby et al. (2019), Antonini et al. (2019). Due to the peculiar bathymetries and topographies of rock pinnacles, there is no dedicated formula to properly quantify the loads induced by the breaking waves on offshore rock lighthouses. Wienke’s formula (Wienke and Oumeraci (2005) was used in this study to estimate the loads, even though it was not derived for breaking waves on offshore rock lighthouses, but rather for the breaking wave loading on offshore monopiles. However, a thorough sensitivity analysis of the effects of the assumed pressure distribution has never been performed. In this paper, by means of the Wolf Rock lighthouse distinct element model, we quantified the influence of the pressure distributions on the dynamic response of the lighthouse structure. Different pressure distributions were tested, while keeping the initial wave impact area and pressure integrated force unchanged, in order to quantify the effect of different pressure distribution patterns. The pressure distributions considered in this paper showed subtle differences in the overall dynamic structure responses; however, pressure distribution #3, based on published experimental data such as Tanimoto et al. (1986) and Zhou et al. (1991) gave the largest displacements. This scenario has a triangular pressure distribution with a peak at the centroid of the impact area, which then linearly decreases to zero at the top and bottom boundaries of the impact area. The azimuthal horizontal distribution was adopted from Wienke and Oumeraci’s work (2005). The main findings of this study will be of interest not only for the assessment of rock lighthouses but also for all the cylindrical structures built on rock pinnacles or rocky coastlines (with steep foreshore slopes) and exposed to harsh breaking wave loading.

Hybrid nanofluid flow over a stretched cylinder with the impact of homogeneous–heterogeneous reactions and Cattaneo–Christov heat flux: Series solution and numerical simulation

Heat Transfer ◽  
2021 ◽  
Author(s):  
Anthonysamy John Christopher ◽  
Nanjundan Magesh ◽  
Ramanahalli Jayadevamurthy Punith Gowda ◽  
Rangaswamy Naveen Kumar ◽  
Ravikumar Shashikala Varun Kumar
Keyword(s):  
Numerical Simulation ◽  
Heat Flux ◽  
Series Solution ◽  
Heterogeneous Reactions ◽  
Hybrid Nanofluid ◽  
Nanofluid Flow ◽  
The Impact

NUMERICAL SIMULATION OF DAM BREAK BY ADAPTIVE STENCIL DIFFUSE INTERFACE METHOD

2009 ◽  
Vol 23 (03) ◽  
pp. 293-296 ◽  
Author(s):  
L. DING ◽  
C. SHU ◽  
N. ZHAO
Keyword(s):  
Numerical Simulation ◽  
Adaptive Algorithm ◽  
Leading Edge ◽  
Dam Break ◽  
Experimental Results ◽  
Diffuse Interface ◽  
Fine Scale ◽  
Experiment Data ◽  
Interface Behavior

This paper presents the application of an adaptive stencil diffuse interface method to the simulation of dam break problem. The adaptive stencil diffuse interface method is the combination of the diffuse interface method and a stencil adaptive algorithm, where the diffuse interface method is used as the solver, and the adaptive stencil refinement scheme is applied to improve the resolution around the interface so that the fine-scale interface behavior can be captured. In this paper, we use this method to simulate the dam break problem, study the dam height and leading edge position, and compare our results with the experiment data available in the literature. It is shown that the results using the adaptive stencil diffuse interface method agree very well with the experimental results.

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