SPH-Based Numerical Modeling of Fluid Flow Interaction with Various Shapes of Breakwater

2019 ◽  
Author(s):  
Rezaldy Naufal Saleh ◽  
Dede Tarwidi ◽  
Jondri
Keyword(s):  
Numerical Modeling ◽  
Fluid Flow ◽  
Coastal Erosion ◽  
Fluid Velocity ◽  
Fluid Motion ◽  
Three Dimensional ◽  
Maximum Velocity ◽  
Sph Method ◽  
Flow Interaction ◽  
Scale Down

Various efforts have been made to prevent coastal erosion. One of the efforts to prevent coastal erosion is to build breakwaters. This paper presents numerical modeling of fluid flow interaction with various shapes of breakwater. Fluid flow impact on different shapes of breakwater, i.e. trapezoidal prism, cylinder, and sphere has been investigated. The three-dimensional numerical modeling is purposed to decisive which breakwaters shape that can reduce the fluid velocity rapidly, compared to other tested breakwaters shapes. In this study, fluid motion is generated by dam break scheme. The fluid motion is governed by momentum and continuity equation. The equations of fluid motion are resolved by smoothed particle hydrodynamics (SPH) method. DualSPHysics, an open-source code based on SPH method, is applied to simulate fluid motion and the interaction with the blocks of breakwater. According to numerical results, the trapezoidal prism shape of breakwater can scale down the fluid velocity faster than the cylinder and sphere shape of breakwater with maximum velocity is about 2.20 m/s. Further, the cylinder shape yields the highest fluid velocity around the breakwater. The trapezoidal prism shape can be used as an effective breakwater.

scholarly journals Modeling of Water Flows around a Circular Cylinder with the SPH Method

2014 ◽  
Vol 61 (1-2) ◽  
pp. 39-60 ◽  
Author(s):  
Kazimierz Szmidt ◽  
Benedykt Hedzielski
Keyword(s):  
Fluid Flow ◽  
Circular Cylinder ◽  
Fluid Velocity ◽  
Fluid Motion ◽  
Plane Boundary ◽  
Cylinder Surface ◽  
Initial Value ◽  
Sph Method ◽  
First Order ◽  
Time Calculation

Abstract The paper describes the SPH modeling of a plane problem of fluid flow around a rigid circular cylinder. In the model considered, the cylinder is placed in a rectangular fluid domain at a certain distance from a horizontal plane boundary, and it is subjected to fluid flow forces. The fluid motion is induced by a piston type generator. The generator - fluid system starts to move from rest at a certain moment of time. The work aims at a discrete description of the fluid flow around the cylinder and, at the same time, calculation of the pressure distribution along the circumference of the cylinder and the resultant of the pressure on the cylinder. In order to solve the initial value problem considered, a new SPH formulation of boundary conditions on the cylinder surface is proposed which match the physical condition for the fluid velocity at this boundary. For a viscous fluid, an approximate description of the stress tensor is formulated which allows to reduce the differentiation of field functions to the first order in calculating the shear forces in the SPH approach.

Fluid mechanics and sound generation for lung-clearance therapy

2017 ◽  
Vol 27 (4) ◽  
pp. 820-838
Author(s):  
John Gorman ◽  
Eph Sparrow ◽  
Kevin Krautbauer
Keyword(s):  
Fluid Flow ◽  
Fluid Mechanics ◽  
Design Methodology ◽  
Complete System ◽  
Fluid Velocity ◽  
Fluid Motion ◽  
Sound Generation ◽  
Content Type ◽  
Primary Means ◽  
Therapeutic Device

Purpose The study described here aims to set forth an analysis approach for a specific biomedical therapeutic device principally involving fluid mechanics and resulting sound generation. The function of the therapeutic device is to clear mucus from the airways of the lungs. Clearance of the airways is a primary means of relief for cystic fibrosis and is also effective in less profound dysfunctions such as asthma. The complete system consists of a device to periodically pulse air pressure and a vest that girdles the abdomen of the patient and receives and discharges the pulsating airflow. The source of pulsed air can be tuned both with respect to the amplitude and frequency of the pressure pulsations. Design/methodology/approach The key design tools used here are computational fluid dynamics and the theory of turbulence-based sound generation. The fluid flow inside of the device is multidimensional, unsteady and turbulent. Findings Results provided by the fluid mechanic study include the rates of fluid flow between the device and the inflatable vest, the rates of air supplied to and extracted from the device, the fluid velocity magnitudes and directions that result from the geometry of the device and the magnitude of the turbulence generated by the fluid motion and the rotating component of the device. Both the velocity magnitudes and the strength of the turbulence contribute to the quantitative evaluation of the sound generation. Originality/value A comprehensive literature search on this type of therapeutic device to clear mucus from the airways of the lungs revealed no previous analysis of the fluid flow and sound generation inside of the device producing the pulsed airflow. The results presented in this paper pinpoint the locations and causes of sound generation that can cause audible discomfort for patients.

scholarly journals A New Approach to Calculate the Velocity of Interdendritic Fluid Flow during Solidification Using Etched Surface Height of Actual Metal Ingot

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 927
Author(s):  
Zibing Hou ◽  
Zhiqiang Peng ◽  
Qian Liu ◽  
Zhongao Guo ◽  
Hongbiao Dong
Keyword(s):  
Fluid Flow ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Bearing Steel ◽  
New Approach ◽  
Velocity Magnitude ◽  
Interdendritic Fluid Flow ◽  
Gcr15 Bearing Steel ◽  
Etched Surface ◽  
Calculated Velocity

Macrosegregation remains one of main defects affecting metal materials properties, which is mainly caused by interdendritic fluid flow during solidifying. However, as for controlling actual specific segregation, it is still difficult to effectively measure or simulate this kind flow instead of pure fluid flow, especially in complex casting processes of high-grade materials. Herein, a new method for obtaining velocity magnitude and direction of interdendritic fluid flow during metal solidifying is proposed from boundary layer and standard deviation obtained by measuring etched surface heights of the actual ingot and using statistical principles. Taking continuous casting bloom of GCr15 bearing steel as an example, it is indicated that the calculated velocity magnitudes under different sides and superheats can be explained by process features and, hence, solidification mechanism. The velocity magnitude and fluctuation are higher on the inner curve side and under low superheat. Meanwhile, it is found that the fluctuation extent of secondary arm spacing is more relevant with interdendritic fluid flow, although its magnitude is mainly determined by the cooling rate. Moreover, on the basis of the calculated velocity directions and magnitudes, there is a positive correlation between segregation area ratio and the effective ratio between interdendritic flow velocity and growth velocity especially in the equiaxed grain zone, which corresponds with classic macrosegregation formation theory. The above findings and comparison with other results demonstrate the validity of the new approach, which can obtain the magnitude and the direction of interdendritic fluid velocity for two or three-dimensional multiscale velocity distribution by tailoring measuring length and numbers.

Numerical and Experimental Analyses of Breakwater Designs for Turbulent Flow Characteristics and Sediment Transport Under Coastal Wave Actions

2020 ◽  
Vol 142 (7) ◽  
Author(s):  
Hairui Wang ◽  
William Foltz ◽  
Ning Zhang ◽  
Dimitrios Dermisis
Keyword(s):  
Coastal Erosion ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Sediment Retention ◽  
Cfd Simulations ◽  
Cfd Models ◽  
Turbulent Characteristics ◽  
Scale Down ◽  
Pass Through ◽  
Coastal Louisiana

Abstract The goal of the study is to identify optimal breakwater designs to be placed on the banks of various water bodies in coastal Louisiana, to prevent the coastal erosion. Coastal erosion is a significant concern for Louisiana's wavy coastline. The loss of coastal wetlands is threatening the environment and the economic development. One of the ways to prevent coastal erosion and wetland losses is by using breakwaters designed to reduce the wave energy and change the transport of sediments brought by the waves. The objective of this research is to analyze the turbulent characteristics around specially designed three-dimensional (3D) breakwaters, and its impact on sediment deposition under coastal wave actions. Both computational fluid dynamics (CFD) simulations and experimental measurements were conducted. In order to validate the CFD models used for this study, the simulation results were compared to data measured from a scale-down experiment. Once the validity of the CFD models has been confirmed on three miniature panels, namely, a solid panel, a panel with three holes, and a panel with eight holes, the simulations were scaled up to the actual size of the designed breakwater panels for tests. The breakwater designs aim to allow sediment pass through the holes, to deposit sediment at target areas, and to reduce wave actions. There were three different panel-design cases simulated in this study. The results of 3D CFD simulations of these panels were compared and analyzed to determine the performance of each design in terms of wave reduction and sediment retention.

Optimization of Valve Block Shape Using CFD

2012 ◽  
Vol 190-191 ◽  
pp. 133-138 ◽  
Author(s):  
Qin Yang ◽  
Xian Zhou Wang ◽  
Ming Yue Liu ◽  
Jing Hu ◽  
Zhi Guo Zhang
Keyword(s):  
Fluid Flow ◽  
High Efficiency ◽  
Complex Geometry ◽  
Numerical Study ◽  
Three Dimensional ◽  
Maximum Velocity ◽  
Check Valve ◽  
Low Noise ◽  
Stop Valve ◽  
Valve Block

Stop valves are commonly used as fluid flow control equipments in many engineering applications. A numerical study of a three-dimensional, complex geometry, stop-check valve was performed for model validation and improved understanding of valve flow features. This paper has provided a numerical investigation of the fluid flow inside a stop valve, including the modeling and the simulation of the stop valves. According to the simulation result of original valve structure, two cone valve block shape with different gradient are presented to bring some optimization to the stop-valve. CFD simulations were conducted for different structure of the valve to verify the performance of the valve after redesign the internal flow structure. The simulation results show that the pressure drop vortex strength, maximum velocity and velocity nonuniformity of valve outlet had been reduced obviously. Furthermore, the results of the three-dimensional optimization analysis of valve shape can be used in the design of low noise and high efficiency valve for industry.

Experimental and Numerical Modeling of Viscous Fluid Flow in Bifurcated Long Pipes for Oil Transport

2020 ◽  
Author(s):  
Victorita Radulescu
Keyword(s):  
Numerical Modeling ◽  
Fluid Flow ◽  
Numerical Solutions ◽  
Fluid Motion ◽  
Reynolds Numbers ◽  
Navier Stokes ◽  
Local Pressure ◽  
Pressure Losses ◽  
Main Pipe ◽  
Experimental And Numerical Modeling

Abstract The present paper presents some experimental and numerical modeling of the Newtonian and viscoelastic flows in bifurcated configurations of pipes, for stationary and non-permanent regimes. The main purpose of this study is to select an optimal design of the pipes ramifications, for minimizing the local pressure losses and to improve the efficiency of fluid transportation. The method is based on the transformation of the flow field obtained with particle image visualization technique, for different Reynolds numbers. Based on experimental results will be established optimum geometry of the ramifications. The results will be used as the boundary conditions for numerical modeling. The experimental measurements were performed into a closed circuit of pipes, with different diameters, consisting of a centrifugal pump supplied by a tank, sensors for estimating the pressure losses and devices for measuring the flow rate. It is detailed presented in a dedicated paragraph. The main pipe is connected to a transparent bifurcation with branches at different angles from the main pipe axis. The measurements illustrate that the flow has different aspects, depending on the bifurcation’s angle. The numerical simulations are performed with Fluent CFD based on the volume numerical method, to obtain the Navier-Stokes solutions for the Newtonian model in the laminar or turbulent flow conditions. A pre-processor has been used to create the geometry of the bifurcation and to generate the mesh. The 3D-flow domain contains 944390 volumes, tetrahedral hybrid. It was obtained the numerical solutions of the fluid flow in branching pipes for the Reynolds numbers from 1000 up to 40000. The governing equations were assumed from the k-ε model for turbulence flow, the equation of continuity, equation of fluid motion, and the transport equation. Finally, some conclusions and references are presented.

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