scholarly journals Landslide mudflow behaviour: physical and numerical modelling

2021 ◽  
Vol 1203 (2) ◽  
pp. 022136
Author(s):  
Fredy Alexander Muñoz Cano ◽  
César Augusto Hidalgo Montoya ◽  
Johnny Alexander Vega Gutiérrez ◽  
Melissa Parra Obando
Keyword(s):  
Numerical Model ◽  
Physical Model ◽  
Newtonian Fluid ◽  
Numerical Models ◽  
Rectangular Channel ◽  
Experimental Tests ◽  
Economic Losses ◽  
Ansys Fluent ◽  
Complex Process ◽  
Scale Experiment

Abstract Landslides constitute one of the natural phenomena that cause the most economic losses and deaths worldwide. After failure occurs, landslides can trigger mudflows. Understanding how mud is transported is very important in infrastructure projects that coincide with hillside areas due to the high risk of this phenomena occurring due to the high slopes, which can imply great risks and produce disasters, generating considerable costs. In this work, the evaluation of a mudflow is presented, from the execution of a scale experiment in the laboratory and its validation from numerical models, considering the material behaviour as a Newtonian fluid and as a non-Newtonian fluid. The physical model was developed using a 3m x 0.5m x 0.7m rectangular channel with dimensions, with slope control. A mud mixture composed of a silty material with 60% of moisture was tested producing a mudflow. Experimental tests were carried out with slopes of 5% and 10%. The numerical models were implemented in ANSYS FLUENT software. At first stage, the numerical model was calibrated with the results of the physical model with a slope of 5% and it was validated with the results of the model for the slope of 10%. Results of the numerical models were compared with the experimental results, and they have shown that these have a great capacity to reproduce what is observed experimentally. In addition, when the material was considerate as a Newtonian fluid, a similar behaviour was found respect to a mudflow as a non-Newtonian fluid, not finding considerable differences in the final deposition length of the flow. The simulation of mudflow, especially multiphase, using CFD is usually a complex process since the boundary conditions and physical and rheological properties of the soil must be correctly defined, considering the contribution of the solid fraction in the behaviour of the numerical model. Nevertheless, despite all the simplifications that a modelling of this type entails, the results are promising to improve the understanding of the phenomenon studied, and its application in risk assessment methodologies for mass movements and their derived effects.

scholarly journals Experimental and numerical analysis of the biomass innovativ solar pyrolysis process

2019 ◽  
Vol 137 ◽  
pp. 01004
Author(s):  
Sebastian Werle ◽  
Szymon Sobek ◽  
Zuzanna Kaczor ◽  
Łukasz Ziółkowski ◽  
Zbigniew Buliński ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Numerical Model ◽  
Input Data ◽  
Experimental Tests ◽  
Real System ◽  
Artificial Light ◽  
Gas Composition ◽  
Pyrolysis Process ◽  
Ansys Fluent ◽  
Main Fraction

Paper present the experimental and numerical analysis of biomass photopyrolysis process. The experimental tests is performed on the solar pyrolysis installation, designed in Institute of Thermal Technology, Gliwice. It consist of the copper reactor powered by artificial light simulating sun. The paper shows the result of the solar pyrolysis of wood. The yield of the main fraction as a function of the process temperature is presented. Additionally the gas composition is determined. The numerical model is prepared in the Ansys Fluent 18.2 software, which allow at the same time for capturing geometry of the real system and easy change of input data. The results indicate that both the product yields (liquid, solid and gaseous) and gas components shares are strongly influenced by pyrolysis parameters and feedstock composition.

Numerical Analysis of Masonry Confined by FRCM

2017 ◽  
Vol 747 ◽  
pp. 558-566 ◽  
Author(s):  
Francesco Saverio Murgo ◽  
Claudio Mazzotti
Keyword(s):  
Numerical Model ◽  
Numerical Models ◽  
Experimental Tests ◽  
Numerical Approach ◽  
Structural Behaviour ◽  
Confined Masonry ◽  
Axial Forces ◽  
Commercial Code ◽  
The University ◽  
Model Approach

In the present paper, structural behaviour of masonry columns strengthened with fiber reinforced cementitious matrix have been investigated; in particular, numerical 3D simulations calibrated on experimental tests have been presented. T hree-dimensional numerical model, realized by using the commercial code MIDAS FEA, based on a macro-model approach, has been used to simulate the nonlinear structural behavior of masonry columns strengthened with FRCM, and two different models for unreinforced and strengthened columns have been adopted. The 3D numerical approach are presented and results discussed to investigate the interaction between masonry columns and reinforcement. The numerical model has been calibrated on a large number of experimental tests on confined masonry columns carried out at the University of Bologna; in particular, columns have been wrapped by FRP and FRCM and with different arrangements (continuous and discontinuous). The comparison of the numerical models with the experimental outcomes shows a good matching in terms of axial forces-strain curves and strength peak.

An experimental and numerical investigation on active compliant joint made by shape memory alloy actuator

2019 ◽  
Vol 234 (2) ◽  
pp. 156-164 ◽  
Author(s):  
Babak Katanchi ◽  
Alireza Fathi ◽  
Mostafa Baghani ◽  
Hamed Afrasyab
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Shape Memory ◽  
Numerical Models ◽  
Niti Alloy ◽  
Experimental Tests ◽  
Finite Element Program ◽  
Heating Source ◽  
Compliant Joint ◽  
Actuator Performance

In this paper, a novel active compliant joint for robotic and microdisplacement applications is investigated numerically and experimentally. The proposed actuator structure is simple and possesses a higher energy density compared to the available actuators. Experimental tests are performed employing the shape memory behavior of NiTi alloy by the electric current as a heating source. To verify the actuator performance, numerical models are simulated in a nonlinear finite element program through employing a user subroutine according to experimental tests. Finite element implementation of the proposed actuator is performed based on the constitutive equations developed in Boyd–Lagoudas phenomenological model. Comparing the test and numerical results revealed that the numerical model is successful in predicting the actuator response. Finally, based on the verified numerical model, the effects of different parameters, e.g. the compression spring stiffness on the actuator performance are studied, and an optimal design for the actuator structure is proposed.

scholarly journals DIC in Validation of Boundary Conditions of Numerical Model of Reinforced Concrete Beams Under Torsion

2018 ◽  
Vol 64 (4) ◽  
pp. 31-48 ◽  
Author(s):  
B. Turoń ◽  
D. Ziaja ◽  
L. Buda-Ożóg ◽  
B. Miller
Keyword(s):  
Reinforced Concrete ◽  
Numerical Model ◽  
Boundary Conditions ◽  
Numerical Simulations ◽  
Experimental Research ◽  
Concrete Beams ◽  
Numerical Models ◽  
Experimental Tests ◽  
Reinforced Concrete Beams ◽  
Image Correlation

AbstractThe paper presents the experimental research and numerical simulations of reinforced concrete beams under torsional load. In the experimental tests Digital Image Correlation System (DIC System) Q-450 were used. DIC is a non-contact full-field image analysis method, based on grey value digital images that can determine displacements and strains of an object under load. Numerical simulations of the investigated beams were performed by using the ATENA 3D – Studio program. Creation of numerical models of reinforced concrete elements under torsion was complicated due to difficulties in modelling of real boundary conditions of these elements. The experimental research using DIC can be extremely useful in creating correct numerical models of investigated elements. High accuracy and a wide spectrum of results obtained from experimental tests allow for the modification of the boundary conditions assumed in the numerical model, so that these conditions correspond to the real fixing of the element during the tests.

scholarly journals Numerical calculations of behaviour of ship double-bottom structure during grounding

2008 ◽  
Vol 15 (Special) ◽  
pp. 22-26 ◽  
Author(s):  
Karol Niklas
Keyword(s):  
Numerical Model ◽  
Numerical Simulations ◽  
Numerical Models ◽  
Experimental Tests ◽  
Numerical Calculations ◽  
Polymer Concrete ◽  
Design Work ◽  
Ship Structure

Numerical calculations of behaviour of ship double-bottom structure during grounding The idea of the CORET project consists in adding, to the existing construction, special polymer-concrete coatings intended for the increasing of ship's capability against losing structural tightness during collision or grounding. In order to correctly design the protective barriers, to perform relevant numerical simulations is necessary. The elaborating of numerical models of ship structure behaviour during collision is very complicated and requires auxiliary simulations (on submodels) to be performed. This paper is devoted to elaborating a numerical model of a fragment of ship double-bottom structure. On the basis of experimental tests it was possible to verify and calibrate the numerical model which may be used in further design work aimed at the increasing of crashworthiness of structure during collision.

scholarly journals Modelling of Flow Patterns over Spillway with CFD (Case Study: Haditha Dam in Iraq)

2021 ◽  
Vol 16 (4) ◽  
pp. 373-385
Author(s):  
Atheer Saleem Almawla ◽  
Ammar Hatem Kamel ◽  
Assim Mohammed Lateef
Keyword(s):  
Numerical Model ◽  
Physical Model ◽  
Turbulence Model ◽  
Low Cost ◽  
Water Pressure ◽  
Ansys Fluent ◽  
Cavitation Damage ◽  
Vof Model ◽  
Computational Fluid Dynamics Cfd ◽  
Radial Gate

Spillways are designing to release surplus water over a volume of storage. The excess water flows from the top of the reservoir and is carried back to the river by a spillway. Many radial gates were destroyed under hydrodynamic load. Radial gate connectors are susceptible to fatigue failure due to excessive vibration; therefore, gate vibration during operation must be investigated to confirm safe operation at the design water pressure. Several studies were carried out to analyse and simulation of flow over the spillway. In this article, the flow pattern over the Haditha dam spillway has been simulated using computational fluid dynamics (CFD). The numerical model was performed using Ansys Fluent 2020 R1 to simulate the flow properties; determination of cavitation damage at three discharges corresponding in the design of Haditha dam are 4700, 7140, and 7900 m3/s. In addition to finding the effect of gate vibration under dynamic water loads. The Realisable k-ɛ turbulence model was utilised with the volume of fluid (VOF) model to simulate the interaction between air and water phases. The validation of the numerical model was achieved by comparing it with a physical model. The physical model of the Haditha Dam spillway was made from iron with a scale of 1:110. It has been designed and constructed in a hydraulic laboratory according to the modelling principle of the hydraulic structure. The results showed that a high agreement between the physical and numerical model and the k-ɛ turbulence model could simulate the Haditha dam spillway with low cost and few times. The cavitation damage may occur at the region start at the end of the arching spillway to stretches downstream, and there is no damage of gate vibration under dynamic water load.

Hull Girder Ultimate Strength of Intact and Damaged Double Hull Tankers

2016 ◽  
Author(s):  
Diogo do Amaral M. Amante ◽  
John Alex Chujutalli ◽  
Segen F. Estefen
Keyword(s):  
Numerical Model ◽  
Ultimate Strength ◽  
Numerical Models ◽  
Experimental Tests ◽  
Small Scale ◽  
Box Girders ◽  
Shell Elements ◽  
Hull Girder ◽  
Damage Scenarios ◽  
Double Hull

The aim of this work is to accomplish an assessment of the hull girder ultimate strength of intact and damaged double hull tankers. First, the paper presents the validation of the numerical model through comparisons with experimental tests of small-scale box girders. The numerical models are represented by shell elements assuming finite membrane strains and large rotations, considering both geometric and material nonlinearities. Simulation results show very good agreement with experimental tests. Then, a numerical model of a double hull tanker was developed and analyzed in the intact and damaged conditions. Several damage scenarios were investigated.

SEISMIC RISK AND RESILIENCE ASSESSMENT OF INDUSTRIAL FACILITIES: CASE STUDY ON A BLACK CARBON PLANT

2020 ◽  
Author(s):  
George Karagiannakis
Keyword(s):  
Seismic Risk ◽  
Numerical Models ◽  
Fragility Curves ◽  
Human Life ◽  
Mitigation Strategies ◽  
Economic Losses ◽  
Risk And Resilience ◽  
Industrial Plants ◽  
Plant Equipment

This paper deals with state of the art risk and resilience calculations for industrial plants. Resilience is a top priority issue on the agenda of societies due to climate change and the all-time demand for human life safety and financial robustness. Industrial plants are highly complex systems containing a considerable number of equipment such as steel storage tanks, pipe rack-piping systems, and other installations. Loss Of Containment (LOC) scenarios triggered by past earthquakes due to failure on critical components were followed by severe repercussions on the community, long recovery times and great economic losses. Hence, facility planners and emergency managers should be aware of possible seismic damages and should have already established recovery plans to maximize the resilience and minimize the losses. Seismic risk assessment is the first step of resilience calculations, as it establishes possible damage scenarios. In order to have an accurate risk analysis, the plant equipment vulnerability must be assessed; this is made feasible either from fragility databases in the literature that refer to customized equipment or through numerical calculations. Two different approaches to fragility assessment will be discussed in this paper: (i) code-based Fragility Curves (FCs); and (ii) fragility curves based on numerical models. A carbon black process plant is used as a case study in order to display the influence of various fragility curve realizations taking their effects on risk and resilience calculations into account. Additionally, a new way of representing the total resilience of industrial installations is proposed. More precisely, all possible scenarios will be endowed with their weighted recovery curves (according to their probability of occurrence) and summed together. The result is a concise graph that can help stakeholders to identify critical plant equipment and make decisions on seismic mitigation strategies for plant safety and efficiency. Finally, possible mitigation strategies, like structural health monitoring and metamaterial-based seismic shields are addressed, in order to show how future developments may enhance plant resilience. The work presented hereafter represents a highly condensed application of the research done during the XP-RESILIENCE project, while more detailed information is available on the project website https://r.unitn.it/en/dicam/xp-resilience.

scholarly journals Two-Dimensional Numerical Modeling of Flow in Physical Models of Rock Vane and Bendway Weir Configurations

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 458
Author(s):  
Drew C. Baird ◽  
Benjamin Abban ◽  
S. Michael Scurlock ◽  
Steven B. Abt ◽  
Christopher I. Thornton
Keyword(s):  
Numerical Modeling ◽  
Physical Model ◽  
Numerical Models ◽  
Hydraulic Performance ◽  
Physical Models ◽  
Protection Measures ◽  
Design Engineers ◽  
Model Study ◽  
Study Results ◽  
Wide Range

While there are a wide range of design recommendations for using rock vanes and bendway weirs as streambank protection measures, no comprehensive, standard approach is currently available for design engineers to evaluate their hydraulic performance before construction. This study investigates using 2D numerical modeling as an option for predicting the hydraulic performance of rock vane and bendway weir structure designs for streambank protection. We used the Sedimentation and River Hydraulics (SRH)-2D depth-averaged numerical model to simulate flows around rock vane and bendway weir installations that were previously examined as part of a physical model study and that had water surface elevation and velocity observations. Overall, SRH-2D predicted the same general flow patterns as the physical model, but over- and underpredicted the flow velocity in some areas. These over- and underpredictions could be primarily attributed to the assumption of negligible vertical velocities. Nonetheless, the point differences between the predicted and observed velocities generally ranged from 15 to 25%, with some exceptions. The results showed that 2D numerical models could provide adequate insight into the hydraulic performance of rock vanes and bendway weirs. Accordingly, design guidance and implications of the study results are presented for design engineers.

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