Numerical Analysis of Breakwaters Turbulence Under Coastal Wave Actions

2018 ◽  
Author(s):  
Huanrong Ouyang ◽  
Joshua Hantz ◽  
Tam Nguyen ◽  
Amy Harrington ◽  
Ning Zhang
Keyword(s):  
Economic Development ◽  
Numerical Analysis ◽  
Coastal Erosion ◽  
Cfd Simulation ◽  
Simulation Analysis ◽  
Turbulence Characteristics ◽  
3 Dimensional ◽  
Pass Through ◽  
The Waves ◽  
Wetland Losses

Due to the coastal wave actions, Louisiana coastline has been experiencing serious depletion of wetlands over decades. The loss of wetlands is threating the environment and the economic development of Louisiana. Therefore, breakwaters are designed to protect the coastline from coastal erosion and wetland losses by dissipating the energy of waves and changing the transport of sediment which is brought by the waves. The objective of this research was to give a numerical analysis of 2-dimensional breakwaters under wave actions and 3-dimensional breakwaters turbulence characteristics under coastal wave actions using CFD simulation. In this research, three breakwater structures are tested: a solid panel with no holes, a panel with three holes, and a panel with eight holes. The breakwater designs aim to allow sediment pass through the holes, to deposit and accumulate sediment at target areas, and to reduce wave actions. There were three different cases simulated with wave actions and without wave actions in this study, each case using a different panel design. The results of this study were mainly compared with the 2-dimensional CFD simulation analysis conducted previously to prove the accuracy.

scholarly journals Computational fluid dynamics (CFD) simulation analysis on retinal gas cover rates using computational eye models

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Makoto Gozawa ◽  
Yoshihiro Takamura ◽  
Tomoe Aoki ◽  
Kentaro Iwasaki ◽  
Masaru Inatani
Keyword(s):  
Cfd Simulation ◽  
Simulation Analysis ◽  
Fluid Dynamic ◽  
Fluid Analysis ◽  
Intraocular Gas ◽  
Pars Plana ◽  
Computational Fluid Dynamics Cfd ◽  
Multiple Breaks ◽  
Gas Volume ◽  
Wall Wettability

AbstractWe investigated the change in the retinal gas cover rates due to intraocular gas volume and positions using computational eye models and demonstrated the appropriate position after pars plana vitrectomy (PPV) with gas tamponade for rhegmatogenous retinal detachments (RRDs). Computational fluid dynamic (CFD) software was used to calculate the retinal wall wettability of a computational pseudophakic eye models using fluid analysis. The model utilized different gas volumes from 10 to 90%, in increments of 10% to the vitreous cavity in the supine, sitting, lateral, prone with closed eyes, and prone positions. Then, the gas cover rates of the retina were measured in each quadrant. When breaks are limited to the inferior retina anterior to the equator or multiple breaks are observed in two or more quadrants anterior to the equator, supine position maintained 100% gas cover rates in all breaks for the longest duration compared with other positions. When breaks are limited to either superior, nasal, or temporal retina, sitting, lower temporal, and lower nasal position were maintained at 100% gas cover rates for the longest duration, respectively. Our results may contribute to better surgical outcomes of RRDs and a reduction in the duration of the postoperative prone position.

scholarly journals CFD Simulation of Solid Suspension for a Liquid–Solid Industrial Stirred Reactor

2021 ◽  
Vol 11 (12) ◽  
pp. 5705
Author(s):  
Adrian Stuparu ◽  
Romeo Susan-Resiga ◽  
Alin Bosioc
Keyword(s):  
Chemical Reaction ◽  
Cfd Simulation ◽  
Simulation Analysis ◽  
Solid Phase ◽  
Initial Conditions ◽  
Chemical Reactor ◽  
Liquid Mixtures ◽  
Multiphase Model ◽  
Chemical Product ◽  
Two Phase

The present study examines the possibility of using an industrial stirred chemical reactor, originally employed for liquid–liquid mixtures, for operating with two-phase liquid–solid suspensions. It is critical when obtaining a high-quality chemical product that the solid phase remains suspended in the liquid phase long enough that the chemical reaction takes place. The impeller was designed for the preparation of a chemical product with a prescribed composition. The present study aims at finding, using a numerical simulation analysis, if the performance of the original impeller is suitable for obtaining a new chemical product with a different composition. The Eulerian multiphase model was employed along with the renormalization (RNG) k-ε turbulence model to simulate liquid–solid flow with a free surface in a stirred tank. A sliding-mesh approach was used to model the impeller rotation with the commercial CFD code, FLUENT. The results obtained underline that 25% to 40% of the solid phase is sedimented on the lower part of the reactor, depending on the initial conditions. It results that the impeller does not perform as needed; hence, the suspension time of the solid phase is not long enough for the chemical reaction to be properly completed.

scholarly journals STRESS AND DEFORMATION STUDY ON CASTELLATED STEEL BEAM WITH TAPERED SHAPE AND HEXAGONAL OPENINGS

SINERGI ◽  
2019 ◽  
Vol 23 (1) ◽  
pp. 61
Author(s):  
Taufiq Ilham Maulana ◽  
Bagus Soebandono ◽  
Aris Susanti
Keyword(s):  
Numerical Analysis ◽  
Open Source Software ◽  
Steel Beam ◽  
Sample Type ◽  
Span Length ◽  
3 Dimensional ◽  
Primary Sample ◽  
Cantilever Structure ◽  
Stress And Deformation ◽  
Regular Section

Castellated steel beam is a beam with a regular section cut into half with a particular pattern and regrouped with welding to increase its height compared to the original. This structure element has been developed in building constructions since many years ago. However, its uniform section along the span will make the modification no longer effective in cantilever structure, unless it has additional adaptation. Therefore, in this study, it is proposed to use a castellated steel beam with a tapered shape to be applied as cantilever structures. A steel beam with IWF section 150x75x5x7 is the primary sample type in this research. Some variations were made such as openings angle for 450 and 500, openings space for 50 mm, 70 mm, and 90 mm, openings diameter for 50 mm, 75 mm, and 100 mm, and span length for 2 m, 2.5 m, 3 m, and 3.5 m. Two open-source software namely FreeCAD and LisaFEA were used to draw solid 3-dimensional samples and to conduct the numerical analysis to determine stress and deformation respectively. From the result, it is known that the smallest stresses and deformations can be achieved by a different angle of openings, openings space, and diameter for each span length.

scholarly journals Influence of Lawns on the Summer Thermal Environment and Microclimate of Heritage Sites: A Case Study of Fuling Mausoleum, China

2020 ◽  
Author(s):  
Xiaoyu Wang ◽  
Peng Liu ◽  
Gongwen Xu
Keyword(s):  
Cfd Simulation ◽  
Simulation Analysis ◽  
Thermal Environment ◽  
Measurement Data ◽  
Ground Temperature ◽  
Rapid Urbanization ◽  
Actual Measurement ◽  
Heritage Sites ◽  
Human Thermal Comfort ◽  
The Impact

Abstract The thermal environment and microclimate of heritage sites has been severely impacted by rapid urbanization. This study collected various meteorological measurement data as a reference for computational fluid dynamics (CFD) simulation settings. Then CFD was applied to simulate the impact of lawns on the thermal environment and microclimate of Fuling Mausoleum. We found that lawns and soil can cool the air through evaporation, and thus have a specific cooling effect on the bricked ground. After lawns were planted, the bricked ground temperature decreased by 1.56–17.54°C than that before lawns were planted at 14:00, a decrease of 2.68%–24.20%. Under normal circumstances, when the wind speed or relative humidity increased, the ground temperature dropped. Greenbelt vegetation can adjust the microclimate and human thermal comfort indicators. The consistency of the difference between the actual measurement and the CFD simulation results shows that CFD simulation can thus accurately reflect the internal temperature field distribution if the selection of simulation parameters is reasonable. Theoretical calculation and analysis, experimental measurement research, and modern computer simulation analysis methods applied together constitute a complete system for studying modern physical environmental problems and can provide reliable and economic results.

scholarly journals The mechanism of regulatory sandboxes for introducing digital innovations: the practice of implementing experimental legal regimes at national and supranational levels

2020 ◽  
Vol 15 (4) ◽  
pp. 130-138
Author(s):  
E. B. Zavyalova ◽  
D. D. Krykanov ◽  
K. A. Patrunina
Keyword(s):  
Economic Development ◽  
Descriptive Analysis ◽  
Legal Regulation ◽  
Digital Economy ◽  
Successful Implementation ◽  
Economic Activities ◽  
Digital Development ◽  
Effective Instrument ◽  
Pass Through ◽  
Legal Mechanism

Introduction. The legal mechanism of regulatory sandboxes is implemented in a number of countries to foster the development of the digital economy. Regulatory sandboxes act as a legal mechanism that allows introducing a special legal regime for new products and services and conducting experiments (with certain restrictions) with their practical usage without violating the national law. The national program “The Digital Economy of the Russian Federation” sets the goal of the development of digital innovations and the corresponding legal regulation. The implementation of transnational strategies of digital development for the EAEU, the CIS, BRICS is considered as a new challenge to the common economic development.Materials and methods. The research is based on the national and international legal acts as well as on national and international strategies of economic development. Among the methods used are comparison, generalization, qualitative and descriptive analysis and case-study method.Results. The study has identified the main forms of regulatory experiments that are implemented in the modern practice of public regulation. The paper proves that the various forms of regulatory experiments (including regulatory sandboxes) are an effective instrument of regulation of the digital innovations. The authors have found the main pass through technologies that are the object of experimental regulation in international practice. The paper sets the criteria for a successful implementation of the concept of supranational regulatory sandboxes that are implemented in several jurisdictions simultaneously.Discussion and conclusion. The study described the main patterns of implementation of regulatory sandboxes for digital innovations; the main characteristics of the regulatory sandboxes’ design were revealed; the general economic activities that can be enhanced by the instrument of regulatory sandboxes for digital innovations were defined.

scholarly journals Performance Evaluation of Shell-and-Tube Heat Exchanger with 3-Fluid Sets using CFD and NTU

2019 ◽  
Vol 9 (1) ◽  
pp. 1416-1420
Keyword(s):  
Heat Exchanger ◽  
Industrial Development ◽  
Cfd Simulation ◽  
Sea Water ◽  
Raw Water ◽  
Power Sector ◽  
Tube Heat Exchanger ◽  
Shell And Tube ◽  
Pass Through ◽  
Good Agreement

Energy generation to the present growing population is a crucial challenge for the power sector. Heat exchangers (HE) plays an important role in the industrial development. In this present work an attempt is made to develop a Shell-and- Tube Heat Exchanger (STHE) with segmental baffles using commercial CATIA V5 and Autodesk CFD Simulation Softwares. TEMA standards are considered for design of STHE with baffle-cut of 25%. 3-different sets of fluids are allowed to pass through the shell and tube sides i.e. Methanol - Sea Water (M-S), Distilled Water – Raw Water (D-R) and Kerosene- Crude Oil (K-C). The boundary conditions imposed for analysis are fluid inlet temperatures and velocities. ϵ-NTU is employed for the validation of simulation results and found good agreement between them. Results are plotted for temperature, pressure and velocity contours. The performance of the STHE is shown best for the K-C fluid set among other fluid sets.

Experimental Study and Numerical Analysis of Sihui Metro Depot and the Superstructure

2012 ◽  
Vol 226-228 ◽  
pp. 176-180
Author(s):  
Jing Zhang ◽  
Bin Zhang ◽  
Ying Hua Liu ◽  
Long Qi Wang ◽  
Yu Bin Wu
Keyword(s):  
Time History ◽  
Field Tests ◽  
Element Model ◽  
Test Analysis ◽  
3 Dimensional ◽  
Dimensional Finite Element ◽  
Calculation Results ◽  
History Of ◽  
The Given ◽  
The Waves

Field tests were carried out on Sihui metro depot of Beijing metro line 1 and its superstructure. The acceleration time history of sleepers and floors of the building was obtained, and the waves-propagation laws of building were studied through the tests. Test analysis shows that the structure vibrations show zigzag tendencies ascends with the height of the building. Based on current situation of Sihui metro depot, a metro-soil-building 3-dimensional finite element model is established on ANSYS. By using actual acceleration of sleepers as inputs, the dynamic responds rule of the superstructure is obtained. Compared calculation results with the experimental results, the given numerical model can predict the vibrations of the building induced by moving trains quite well. This method can provide guidance and technical support for future development of superstructure.

A Numerical Study on Flow Characteristics Through Orifice Flowmeter and Measurement Accuracy Depending on Upstream Straight Length

2017 ◽  
Author(s):  
Jang Il Lee ◽  
Ae Ju Cheong ◽  
Bok Ki Min
Keyword(s):  
Numerical Analysis ◽  
Measurement Accuracy ◽  
Performance Test ◽  
Swirling Flow ◽  
Numerical Study ◽  
Flow Characteristics ◽  
Orifice Plate ◽  
3 Dimensional ◽  
Ansys Cfx ◽  
Axial Velocity Profile

In this numerical study, Commercial CFD (Computational Fluid Dynamics) code, ANSYS CFX ver. 17.1, is used to analyze the 3-Dimensional flow characteristics through orifice plate (β = 0.6) with two 90 degree bends in different planes. The purpose of this numerical study is to evaluate measurement accuracy and flow characteristics of orifice flowmeter depending on upstream straight length from 12D to 56D. Thus, numerical calculations of pressure drop caused by swirling flow and distortion of axial velocity profile on orifice plate are performed by using numerical analysis. In addition, numerical analysis results are compared with recommended upstream straight length of ASME Performance Test Codes 19.5 for orifice plates and nozzles. The results show that if upstream straight length of orifice flowmeter is more than 40D, there is a little deviation of differential pressure. Moreover, it is found that up-down asymmetry of recirculation zones is relatively attenuated as the upstream straight length increases.

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