scholarly journals Two-dimensional numerical modeling of wood transport

2014 ◽  
Vol 16 (5) ◽  
pp. 1077-1096 ◽  
Author(s):  
Virginia Ruiz-Villanueva ◽  
Ernest Bladé ◽  
Martí Sánchez-Juny ◽  
Belén Marti-Cardona ◽  
Andrés Díez-Herrero ◽  
...  
Keyword(s):  
Simulation Software ◽  
Two Dimensional ◽  
Flume Experiments ◽  
Hydraulic Simulation ◽  
Transport Dynamics ◽  
Drag Forces ◽  
Motion Threshold ◽  
Balance Of Forces ◽  
Volume Method ◽  
Wood Transport

The transport of wood material in rivers has been the subject of various studies in recent years. Most research has focused on the ecological and geomorphologic role of wood, its recruitment processes and spatial distribution in streams. In this study, we focused on wood transport dynamics, and we have developed a numerical model to simulate wood transport coupled with a two-dimensional (2D) hydrodynamic model. For this purpose, wood drag forces were incorporated as additional source terms into the shallow water equations, which are solved together with wood transport by using the finite volume method. This new tool has been implemented as a computational module into ‘Iber’, a 2D hydraulic simulation software. The new module analyzes the initial motion threshold of wood based on the balance of forces involved in the wood's movement, and computes the position and velocity of differently shaped logs using a kinematic approach. The method also considers the interaction between the logs themselves and between the logs and the channel walls or boundaries. Flume experiments were used in a straight channel with obstructions to validate the model's capacity to accurately reproduce the movement of floating logs.

Numerical analysis and explore of asymmetrical fluid flow in a two-sided lid-driven cavity

2020 ◽  
Vol 14 (3) ◽  
pp. 7269-7281
Author(s):  
El Amin Azzouz ◽  
Samir Houat
Keyword(s):  
Velocity Ratio ◽  
Two Dimensional ◽  
Lower Side ◽  
Square Cavity ◽  
Driven Cavity ◽  
Parallel Motion ◽  
Bottom Cavity ◽  
Secondary Vortices ◽  
Volume Method ◽  
Fluid Characteristics

The two-dimensional asymmetrical flow in a two-sided lid-driven square cavity is numerically analyzed by the finite volume method (FVM). The top and bottom walls slide in parallel and antiparallel motions with various velocity ratio (UT/Ub=λ) where |λ|=2, 4, 8, and 10. In this study, the Reynolds number Re1 = 200, 400, 800 and 1000 is applied for the upper side and Re2 = 100 constant on the lower side. The numerical results are presented in terms of streamlines, vorticity contours and velocity profiles. These results reveal the effect of varying the velocity ratio and consequently the Reynolds ratio on the flow behaviour and fluid characteristics inside the cavity. Unlike conventional symmetrical driven flows, asymmetrical flow patterns and velocity distributions distinct the bulk of the cavity with the rising Reynolds ratio. For λ>2, in addition to the main vortex, the parallel motion of the walls induces two secondary vortices near the bottom cavity corners. however, the antiparallel motion generates two secondary vortices on the bottom right corner. The parallel flow proves affected considerably compared to the antiparallel flow.

Design of Control System for Hydraulically Vibrated Processing Tomato Fruit Seedling Separation Device

2014 ◽  
Vol 651-653 ◽  
pp. 693-696
Author(s):  
Li Hong Wang ◽  
Rong Qing Liang ◽  
Cheng Song Li ◽  
Za Kan ◽  
Jin Wei Qin
Keyword(s):  
Tomato Fruit ◽  
Simulation Software ◽  
Signal Frequency ◽  
System Control ◽  
Frequency Range ◽  
Hydraulic Simulation ◽  
Separation Device ◽  
Processing Tomato ◽  
Input Signal Frequency ◽  
Set Up

Eccentric style processing tomato fruit seeding separation device exist high machining and assembly precision or other issues. In order to solve this problem, the mode of vibration of hydraulic replaced the eccentric style to drive the fruit seedling separation roller to separate processing tomato effectively. To facilitate adjustment of the hydraulic system, a kind of control circuit PLC as the core was designed according to the actual production requirements. PLC and other elements were selected. The system control signal frequency was initially set up as 1~5 HZ, within the frequency range hydraulic simulation software was used to simulate and analyze the hydraulic vibration system. The result shows that the system rams steady when the input signal frequency range was 1~5HZ.

scholarly journals Discontinuous finite volume element method of two-dimensional unsaturated soil water movement problem

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Fan Chen ◽  
Zhixiao Xu
Keyword(s):  
Soil Water ◽  
Finite Volume ◽  
Unsaturated Soil ◽  
Water Movement ◽  
Optimal Error Estimate ◽  
Two Dimensional ◽  
Fully Discrete ◽  
Volume Method ◽  
Movement Problem ◽  
Soil Water Movement

AbstractIn this paper, a numerical approximation method for the two-dimensional unsaturated soil water movement problem is established by using the discontinuous finite volume method. We prove the optimal error estimate for the fully discrete format. Finally, the reliability of the method is verified by numerical experiments. This method is not only simple to calculate, but also stable and reliable.

Bifurcation analysis of two-dimensional laminar flow through sudden expansion channel

2022 ◽  
Vol 13 (1) ◽  
pp. 0-0
Keyword(s):  
Laminar Flow ◽  
Expansion Ratio ◽  
Sudden Expansion ◽  
Two Dimensional ◽  
Governing Equations ◽  
Bifurcation Phenomena ◽  
Different Types ◽  
Fluent Software ◽  
Flow Through ◽  
Volume Method

In this work, bifurcation characteristics of unsteady, viscous, Newtonian laminar flow in two-dimensional sudden expansion and sudden contraction-expansion channels have been studied for different values of expansion ratio. The governing equations have been solved using finite volume method and FLUENT software has been employed to visualize the simulation results. Three different mesh studies have been performed to calculate critical Reynolds number (Recr) for different types of bifurcation phenomena. It is found that Recr decreases with the increase in expansion ratio (ER).

scholarly journals Design of Fixed-Wing and Multi-Copter Hybrid Drone System for Human Body Temperature Measurement during COVID-19 Pandemic

2021 ◽  
Vol 20 ◽  
pp. 31-39
Author(s):  
Zayed Almheiri ◽  
Rawan Aleid ◽  
Sharul Sham Dol
Keyword(s):  
Body Temperature ◽  
Temperature Measurement ◽  
Human Body ◽  
Equivalent Strain ◽  
Simulation Software ◽  
Operational Conditions ◽  
Drag Forces ◽  
Human Body Temperature ◽  
Body Temperature Measurement ◽  
Lift And Drag

The purpose of this research is to conduct aerodynamics study and design a hybrid drone system of fixed-wing and multi-copter. The mission of this drone is to measure human body temperature during COVID19 pandemic. The specific aim of the drone is to fly and cover larger industrial areas roughly about 50 km2 with longer flying time than the conventional drone, of about 1.5 hours. The applications of the simulation software such as XFLR5 and ANSYS have a big impact in identifying areas that need to be improved for the drone system. XFLR5 software was used to compare the characteristics of different airfoils with highest lift over drag, L/D ratio. Based on the airfoil selection, it was found that NACA 4412 airfoil produces the highest L/D ratio. The detailed geometry of the drone system includes a fuselage length of 1.9 meters and wingspan of 2 meters. Moreover, 10 sheets of solar panels were placed along the wing for sustainable flight operation to cover wider areas of mission. The structural analysis was done on ANSYS to test the elastic stress, equivalent strain, deformation, factor of safety pressure as well as lift and drag forces under various operational conditions and payloads. The landing gear was analyzed for harsh landing. ANSYS Computational Fluid Dynamics (CFD) was utilized to study the aerodynamics of the drone at different parameters such as the velocities and angles of attack during the operation. This design ensures the stability of the drone during the temperature measurement phase. The best thermal-imaging camera for such purpose would be the Vue Pro R 336, 45° radiometric drone thermal camera with a resolution of 640 x 512 pixels. This camera has the advantage of a permanent continuous out focus that give the ability of taking measurements even if there was changing on the altitude or any kind of vibrations.

scholarly journals OPTIMIZING THE VELOCITY OF RING SHAPE PARAMETER FOR DESIGNING THE NOZZLES USING CFD

2021 ◽  
pp. 1-10
Author(s):  
Obai Younis ◽  
Reem Ahmed ◽  
Ali Mohammed Hamdan ◽  
Dania Ahmed
Keyword(s):  
Shape Parameter ◽  
Maximum Velocity ◽  
Simulation Software ◽  
Governing Equations ◽  
Ansys Fluent ◽  
Ring Shape ◽  
Ring Location ◽  
Computational Fluid Dynamics Cfd ◽  
Triangular Elements ◽  
Volume Method

This study aims to optimize the velocity of ring shape parameter for designing the nozzles using computational fluid dynamics (CFD) and investigated the flow in nozzles using ANSYS, Inc. simulation software. The model geometries were defined using ANSYS FLUENT-Design Modeler platform. All nozzles were designed on unstructured triangular elements comprising of 1200000 mesh nodes. The differential governing equations were applied in ANSYS FLUENT based on a finite volume method. The distance and dimensions of ring location significantly influence the velocity of water during flow where the maximum velocity at double rings reduces the surface area at distance of 7mm and 15mm and 2x2 mm dimensions. Considering 8, 10, and 12 bar liner proportions, there was an increase in the velocity at maximum points in ring shapes.

Single Degree Vibration Platform Self-Tuning Fuzzy PID Controller Design Based on AMESim

2013 ◽  
Vol 310 ◽  
pp. 518-523
Author(s):  
Zhi Qiang Chao ◽  
Xin Ze Li ◽  
Ai Hong Meng
Keyword(s):  
Hydraulic System ◽  
Pid Controller ◽  
Fuzzy Controller ◽  
Controller Design ◽  
Simulation Software ◽  
Fuzzy Pid ◽  
Hydraulic Simulation ◽  
Fuzzy Pid Controller ◽  
Single Degree ◽  
Self Tuning

In recent years, hydraulic simulation has become an important means to research hydraulic system, in order to enable the single degree platform vibration curve with better traceability and reach the requirement of the test, this paper represent single degree system platform stimulated by simulation software AMESim, taking the Single degree freedom vibration hydraulic system as an example, MATlab/simulink is applied to the design of the vibration platform system fuzzy PID controller. Through the comparison between the simulation test and traditional PID controller, the designed self-tuning fuzzy controller can control the platform better, with smaller overshoot, faster response, shorter adjusting time, as well as fulfill the permissible accuracy.

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