Numerical and experimental investigation for the effect of permeability of spur dikes on local scour

Abstract The effect of using permeable spur dikes on the produced maximum scour depth compared to that of solid spur dikes is numerically investigated. The numerical model used for such purpose is the Nays-2DH model of the International River Interface Cooperative (iRIC) software package for bed and bank erosion. The model results are verified using the experimental data collected in this study by conducting experiments on five different models of spur dikes having different opening ratios. Using the statistical performance indices, the root mean square error and the coefficient of determination, the results showed an acceptable agreement between the numerical model results for the relative maximum scour depth defined by the ratio of the maximum scour depth to the flow depth and their corresponding observed values. A new empirical equation using nonlinear regression is developed using the experimental data collected in this study and tested with another existing empirical equation available in the literature for their accuracy in determining the relative maximum scour depth.

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Estimation of maximum scour depth near a spur dike

Canadian Journal of Civil Engineering ◽

10.1139/cjce-2015-0280 ◽

2016 ◽

Vol 43 (3) ◽

pp. 270-278 ◽

Cited By ~ 16

Author(s):

Manish Pandey ◽

Z. Ahmad ◽

P.K. Sharma

Keyword(s):

Natural Phenomenon ◽

Scour Depth ◽

Flowing Water ◽

Performance Indices ◽

Spur Dike ◽

Bed Erosion ◽

River Bed ◽

Spur Dikes ◽

Dike Failure ◽

Better Than

Scour is a natural phenomenon in rivers caused by the erosive action of the flowing water on the bed and banks. Spur dikes are constructed across the flow to protect the bank from erosion by shifting of the river away from the bank. The spur dike undermines due to river-bed erosion and scouring, which is generally recognized as the main cause of spur dike failure. In this study, accuracy of existing equations for the computation of maximum scour depth has been checked with available data in the literature and data collected in the present study using graphical and statistical performance indices. Three new relationships are also proposed to estimate the maximum scour depth and maximum scour length upstream and downstream of spur dike. This new relationship for maximum scour depth is shown to perform better than other existing equations.

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Validating Visual Modflow Numerical Model to Predict Future Impact of Brine Disposal on Groundwater

Journal of Engineering Research and Reports ◽

10.9734/jerr/2019/v5i116913 ◽

2019 ◽

pp. 1-9

Author(s):

Neveen B. Abd El-Mageed ◽

Muhammad A. Abdul-Muttalib ◽

Yasmen A. Heiba

Keyword(s):

Experimental Data ◽

Numerical Model ◽

Salt Concentration ◽

Simulated Data ◽

Numerical Code ◽

Visual Modflow ◽

Brine Disposal ◽

Acceptable Agreement ◽

Over Time

The aim of this research was to simulate the brine disposal fate within an aquifer. The Visual MODFLOW numerical code was used to predict the salt concentration emigration over time in an aquifer. The model was calibrated using laboratory experimental data. The model results revealed that there is an acceptable agreement between the observed and simulated data.

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Prediction of Seabed Scour Induced by Full-Scale Darrieus-Type Tidal Current Turbine

Journal of Marine Science and Engineering ◽

10.3390/jmse7100342 ◽

2019 ◽

Vol 7 (10) ◽

pp. 342 ◽

Cited By ~ 4

Author(s):

Sun ◽

Lam ◽

Dai ◽

Hamill

Keyword(s):

Experimental Data ◽

Numerical Model ◽

Tidal Current ◽

Full Scale ◽

Scale Model ◽

Small Scale ◽

Scour Depth ◽

Equilibrium Scour Depth ◽

Tidal Current Turbine ◽

Current Turbine

Scour induced by a Darrieus-type tidal current turbine was investigated by using a joint numerical and experimental method with emphasis on the scour process of a full-scale turbine. This work proposes a new numerical method to estimate turbine scour developments, followed by model validation through experimental data in the initial stage. The small-scale numerical model was further extended to a full-scale model for the prediction of turbine scour. The numerical model consists of (1) k-ω turbulence closure, (2) a sediment transport model, and (3) a sediment slide model. The transient-state model was coupled with a morphologic model to calculate scour development. A dynamic mesh updating technique was implemented, enabling the autoupdate of data for the grid nodes of the seabed at each time step. Comparisons between the numerical results and the experimental measurements showed that the proposed model was able to capture the main features of the scour process. However, the numerical model underestimated about 15%–20% of the equilibrium scour depth than experimental data. An investigation of the temporal and spatial development of seabed scour around a full-scale Darrieus-type tidal current turbine is demonstrated. This work concludes that the proposed numerical model can effectively predict the scour process of tidal current turbines, and the rotating rotor has a significant impact on the equilibrium scour depth for full-scale turbines.

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Numerical scour modeling around parallel spur dikes in FLOW-3D

10.5194/dwes-2017-21 ◽

2017 ◽

Cited By ~ 3

Author(s):

Hanif Pourshahbaz ◽

Saeed Abbasi ◽

poorya taghvaei

Keyword(s):

Numerical Model ◽

3D Model ◽

Flow Characteristics ◽

3D Models ◽

Scour Depth ◽

Spur Dike ◽

Accuracy Level ◽

Bank Protection ◽

Numerical Research ◽

Spur Dikes

Abstract. Spur dikes are some structures which are built in the flow path with the aim of changing flow characteristics in order to bed and bank protection in rivers. These sudden changes in properties caused by the existence of spur dikes, produces erosion and sedimentation around them. In this paper, effects of series of parallel spur dikes have been investigated numerically. For this purpose, by using experimental and numerical research results from technical literatures, the numerical model conducted in FLOW-3D commercial software and the data were compared with experimental and SSIIM results. The results showed that Froude number and the ratio of U/Ucr affect the accuracy of the models. As a result, by discharge increasing, FLOW-3D models need to be calibrated again. Also, by using a calibrated FLOW-3D model, calculation accuracy of the scour depth at the bottom of the spur dikes becomes better and the accuracy level in the modeling of the surface morphology improves 7 percent more than SSIIM software in the bottom of the first spur dike, more than 80 percent at the bottom of the second spur dike and approximately 40 percent at the bottom of the last spur dike.

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Evaluation of Harmony Search Optimization to Predict Local Scour Depth around Complex Bridge Piers

Civil Engineering Journal ◽

10.28991/cej-0309100 ◽

2018 ◽

Vol 4 (2) ◽

pp. 402 ◽

Cited By ~ 17

Author(s):

Habibeh Ghodsi ◽

Mohammad Javad Khanjani ◽

Ali Asghar Beheshti

Keyword(s):

Experimental Data ◽

Search Algorithm ◽

Harmony Search ◽

Local Scour ◽

Bridge Piers ◽

Coefficient Of Determination ◽

Percentage Error ◽

Scour Depth ◽

Empirical Equations ◽

Statistical Indices

One of the main causes of bridge collapse may be flood flow scour near piers. Several experimental and local field investigations were carried out to study scour depth. However, existing empirical equations do not commonly provide accurate scour prediction due to the complexity of the scour process. Physical and economic considerations often lead to bridge foundation constructs which included a pier column based on a pile cap supported by an array of piles. Piers with this configuration are referred to as complex piers. A few studies have been done on complex bridge pier scour depth estimation. Such efforts may be classified into theoretical and empirical equations. This paper investigates local scour around complex bridge piers by using harmony search algorithm under clear water conditions. Statistical indices such as the coefficient of determination (R2), root mean square error (RMSE), mean absolute error (MAE), mean absolute percentage error (MAPE), and bias were used to evaluate the performance of these methods. By designing laboratory tests, 82 experimental data points were measured by authors. Also 615 experimental data sets with the same measured experimental conditions were collected from published literature and used for optimization. The results show that the developed HS model can predict scour depth better than other equations according to statistical indices.

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Mass Transfer in Liquid in an Apparatus with Mobile Packing. Application of a Dispersion Model

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19931078 ◽

1993 ◽

Vol 58 (5) ◽

pp. 1078-1086

Author(s):

Zdeněk Palatý

Keyword(s):

Experimental Data ◽

Mass Transfer ◽

Empirical Equation ◽

Dispersion Model ◽

Transfer Coefficients ◽

Mass Transfer Coefficients

The paper deals with the mass transfer in a liquid on a plate with mobile packing. A procedure has been suggested which enables estimation of the mass transfer coefficients from experimental data considering the dispersion flow of the liquid. The results obtained from the desorption of CO2 from water are presented graphically and in the form of empirical equation.

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Investigation of the Thickness Differential on the Formability of Aluminum Tailor Welded Blanks

Metals ◽

10.3390/met11060875 ◽

2021 ◽

Vol 11 (6) ◽

pp. 875

Author(s):

Jie Wu ◽

Yuri Hovanski ◽

Michael Miles

Keyword(s):

Experimental Data ◽

Finite Element ◽

Numerical Model ◽

Plastic Strain ◽

Finite Element Model ◽

Equivalent Plastic Strain ◽

Element Model ◽

Dome Height ◽

Tailor Welded Blanks ◽

Simulation Results

A finite element model is proposed to investigate the effect of thickness differential on Limiting Dome Height (LDH) testing of aluminum tailor-welded blanks. The numerical model is validated via comparison of the equivalent plastic strain and displacement distribution between the simulation results and the experimental data. The normalized equivalent plastic strain and normalized LDH values are proposed as a means of quantifying the influence of thickness differential for a variety of different ratios. Increasing thickness differential was found to decrease the normalized equivalent plastic strain and normalized LDH values, this providing an evaluation of blank formability.

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Research Regarding the Effects of 120 mm HE Mortar Bombs on Advanced Materials

Advanced Engineering Forum ◽

10.4028/www.scientific.net/aef.42.128 ◽

2021 ◽

Vol 42 ◽

pp. 128-134

Author(s):

Daniela Pintilie ◽

Iuliana Florina Pană ◽

Adrian Malciu ◽

Constantin Puică ◽

Cristina Pupăză

Keyword(s):

Experimental Data ◽

Numerical Model ◽

Initial Velocity ◽

High Explosive ◽

Numerical Approach ◽

Advanced Materials ◽

Physical Mechanisms ◽

Shock Wave Generation ◽

3D Numerical Model ◽

Experimental Trials

High Explosive Mortar bombs are used on the battlefield for destroying the manpower, non-armoured equipment and shelters. The paper describes an original experimental and numerical approach regarding the potential threats caused by the detonation of 120 mm HE mortar bombs. The evaluation of the bomb effect presumes the fulfillment of experimental trials that focus on two physical mechanisms which appear after the detonation of the cased high explosive. These mechanisms are the shock wave generation and the fragments propulsion, which were also studied by a numerical model that provides results over the bomb fragmentation mode. The novelty of the paper consists in the calibrated 3D numerical model confirmed by the experimental data, which provides information over the fragmentation process of the case and the initial velocity of its fragments, proving that the main threat of this type of ammunition is the effect through metal fragments. The results of numerical simulation and experimental data are used for their comparative analysis and the assessment of the phenomena.

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