The Influence of the Damping Hole Parameters on the Performance of Double Nozzle Flapper Valve Basing on the Orthogonal Test

2012 ◽  
Vol 233 ◽  
pp. 35-38
Author(s):  
Xiang Hui Lu ◽  
Dian Rong Gao
Keyword(s):  
Three Dimensional ◽  
Flow Characteristics ◽  
Orthogonal Test ◽  
Power Losses ◽  
Analysis Software ◽  
Three Dimensional Model ◽  
Fluid Analysis ◽  
Table Analysis ◽  
Best Parameter ◽  
Cfd Method

This paper analyses the flow of the double nozzle flapper valve. Three-dimensional model is established with software Pro/E, fluid analysis software is used for modeling and meshing, CFD method is applied for researching pressure, and flow characteristics of the fixed damping hole is researched when parameters of double nozzle flapper valve is varied. The results show that: the highest velocity through the fixed orifice hole is about 150m/s, the pressure is about 5.9MPa; Using orthogonal test to analyze the simulation results, it is obtained that the power losses of the double nozzle flapper with the change of the diameter, length and the angle of the fixed orifice, the influencing factors on the power losses are the diameter, length and the angle, and the best parameter combination through orthogonal table analysis is gained, which can provide the reference for the whole designing of the double nozzle flapper valve.

3-D Model of Proton Exchange Membrane Fuel Cells

2000 ◽  
Author(s):  
Tianhong Zhou ◽  
Hongtan Liu
Keyword(s):  
Fuel Cell ◽  
Proton Exchange Membrane ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Pem Fuel Cell ◽  
Proton Exchange ◽  
Three Dimensional Model ◽  
Chemical Reaction Kinetics ◽  
Fuel Cell Performance ◽  
D Model

Abstract A comprehensive three-dimensional model for a proton exchanger membrane (PEM) fuel cell is developed to evaluate the effects of various design and operating parameters on fuel cell performance. The geometrical model includes two distinct flow channels separated by the membrane and electrode assembly (MEA). This model is developed by coupling the governing equations for reactant mass transport and chemical reaction kinetics. To facilitate the numerical solution, the full PEM fuel cell was divided into three coupled domains according to the flow characteristics. The 3-D model has been applied to study species transport, heat transfer, and current density distributions within a fuel cell. The predicated polarization behavior is shown to compare well with experimental data from the literature. The modeling results demonstrate good potential for this computational model to be used in operation simulation as well as design optimization.

Numerical and Experimental Analysis of 3D Micro-Corrugated Wing in Gliding Flight

2021 ◽  
Author(s):  
Nasim Chitsaz ◽  
Kamran Siddiqui ◽  
Romeo Marian ◽  
Javaan S. Chahl
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Aerodynamic Performance ◽  
Numerical Results ◽  
Three Dimensional Model ◽  
Wing Model ◽  
Computational Fluid Dynamics Analysis ◽  
Gliding Flight ◽  
Flat Profile

Abstract In this study, computational fluid dynamics analysis was performed on a three-dimensional model of a Libellulidae wing to determine aerodynamic performance in gliding flight. The wing is comprised of various corrugated features alongside the spanwise and chordwise directions, as well as twist. The detailed features of real 3D dragonfly wing models, including all the corrugations through both span and chord, have not been considered in the past for a detailed aerodynamic analysis. The simulations were conducted by solving the Navier-Stokes equations to demonstrate gliding performance over a range of angles of attack at low Reynolds numbers. The numerical model was validated against experimental data obtained from a fabricated corrugated wing model using particle image velocimetry. The numerical results demonstrate that bio-inspired wings with corrugations compared to flat profile wings generate more lift with lower drag, trapping the vortices in the valleys of wing corrugation leading to delayed flow separation and delayed stall. The experimental and numerical results demonstrate that the methodology presented in this study can be used to measure bio-inspired 3D wing flow characteristics, including the influence of complex corrugations on aerodynamic performance. These findings contribute to the advancement of knowledge required for designing an optimized bioinspired micro air vehicle.

Quantitative Analysis of Gas Flow in a Planar SOFC

2012 ◽  
Vol 472-475 ◽  
pp. 2084-2087 ◽  
Author(s):  
Kai Wang ◽  
Yi Sheng Zhang ◽  
Jian Li
Keyword(s):  
Quantitative Analysis ◽  
Gas Flow ◽  
Three Dimensional ◽  
Analysis Method ◽  
Three Dimensional Model ◽  
Velocity Change ◽  
Gas Channel ◽  
Negative Effect ◽  
Quantitative Analysis Method ◽  
Cfd Method

Computational Fluid Dynamics (CFD) method was adopted to establish the three dimensional model for cathode gas channel of planar SOFC and simulate the gas flow in the channel of a single cell. A quantitative analysis method was presented to research the status of gas flow. The characteristics and diagram of velocity change were obtained by using the quantitative analysis method. Furthermore, it was found that gas leak has a negative effect on the uniformity of gas flow, which is more obvious in the region near the leak side.

Effect of Blade Numbers on Pressure Drop of Axial Cyclone Separators by CFD

2011 ◽  
Vol 55-57 ◽  
pp. 343-347 ◽  
Author(s):  
Yi Gang Luan ◽  
Hai Ou Sun
Keyword(s):  
Pressure Drop ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Three Dimensional Model ◽  
Navier Stokes Equations ◽  
Pressure Drops ◽  
Computational Fluid Dynamics Cfd ◽  
Cfd Method ◽  
Resistance Performance

In this article, computational fluid dynamics(CFD) method is used to predict the effect of blade numbers on the pressure drop of axial cyclone separators. A three-dimensional model is built to acquire the resistance of axial cyclone separators with different blade numbers. The flow field inside cyclone separators is calculated using 3D Reynolds-averaged Navier-Stokes equations. And turbulence model is used to simulate the Reynold stress. Also pressure drop of cyclone separators with different blade numbers is expressed as a function of different inlet velocities. At the same inlet velocity with increasing the blade numbers, pressure drops of cyclones reduce greatly. And changing the blade number of cyclone separator is an effective method to improve its resistance performance.

The Analysis of Optimal Clamping Scheme Based on Genetic Algorithm

2014 ◽  
Vol 1055 ◽  
pp. 218-223
Author(s):  
Jin Yu ◽  
Xiu Feng Zhu ◽  
Yan Liang Gao
Keyword(s):  
Genetic Algorithm ◽  
Three Dimensional ◽  
Milling Process ◽  
End Mill ◽  
Analysis Software ◽  
Three Dimensional Model ◽  
Element Analysis ◽  
Simulation And Optimization ◽  
Average Deformation ◽  
The Finite Element Analysis

This paper indicates a kind of research on the optimization of clamping scheme for the joint thin-walled parts in milling process .The three-dimensional model of four-flute end mill and the part are made by UG. The effect of different clamping scheme on the deformation of joint structure is simulated by the finite element analysis software ABAQUS. With the purpose of getting the minimum of the average deformation, MATLAB genetic algorithm optimizes the clamping scheme and acquires the best clamping scheme. The simulation and optimization provide an effective method for controlling the deformation due to different clamping scheme of aeronautic joint-shaped workpiece.

The Simulation and Optimization on Flow Field in Intake Port of Engine Based on RE and CFD

2014 ◽  
Vol 1079-1080 ◽  
pp. 926-929
Author(s):  
Dan Han ◽  
Qian Wang ◽  
Bing Huan Li ◽  
Guo Jun Zhang ◽  
Shuo Wang
Keyword(s):  
Flow Field ◽  
Laser Scanning ◽  
Gas Flow ◽  
Gasoline Engine ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Turbulence Models ◽  
Intake Port ◽  
Three Dimensional Model ◽  
Simulation And Optimization

Intake port is an important part of the gasoline engine, its structure will influence the gas flow characteristics which directly affects the performance of the engine [1]. In this paper, three-dimensional CFD calculation and structural optimization were used to research the performance of gasoline engine. Firstly, the method of laser scanning and UG software were used to reverse modeling engine exhaust port and get the three-dimensional model. Secondly, after setting boundary conditions and turbulence models, the air flowing through the intake ports were simulated by FLUENT software respectively. Finally, based on numerical methods, the pressure field, velocity field were shown. The results of the simulation of flow field characteristics analysis show that the simulation and experimental results are in good agreement.

Simulation Research on Micro-Cavity Flow Field Characteristics of Liquid Floating Rotor Gyro

2013 ◽  
Vol 562-565 ◽  
pp. 490-495 ◽  
Author(s):  
Yu Peng Shi ◽  
Fei Tang ◽  
Xiao Hao Wang
Keyword(s):  
Flow Field ◽  
Boundary Conditions ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Cavity Flow ◽  
Three Dimensional Model ◽  
Simulation Research ◽  
Resistance Torque ◽  
Flow Field Characteristics ◽  
Micro Cavity

The liquid floating rotor gyro is a gyroscope using electrostatic or electromagnetic forces to levitate rotor, and filling rotor-stator cavities with liquid in order to improve stability of motion. Under influence of the relative surface roughness, rotor velocity, dimension of flow field and fluid nature, flow characteristics of cavity flow field vary under different boundary conditions and geometrical conditions. This paper adopts three-dimensional model and periodic boundary conditions to conduct numerical modeling on cavity flow field. Its results show that, with velocity rising, distribution of flow field speed and pressure manifests partial fluctuations in turbulent-flow-intensive area; resistance torque amid rotor rotation is nonlinearly correlated with velocity, whose rules can be obtained through high-order curve fitting.

scholarly journals Influence of the occlusal contacts in formation of Abfraction Lesions in the upper premolar

2017 ◽  
Vol 20 (4) ◽  
pp. 115 ◽  
Author(s):  
Victória Luswarghi Souza Costa ◽  
João Paulo Mendes Tribst ◽  
Alexandre Luiz Souto Borges
Keyword(s):  
Three Dimensional ◽  
Cervical Region ◽  
Shear Stresses ◽  
Dimensional Model ◽  
Analysis Software ◽  
Three Dimensional Model ◽  
Finite Elements Analysis ◽  
Element Analysis ◽  
Occlusal Contact ◽  
Biomechanical Behavior

<p><strong>Objective:</strong> The aim of this study was to observe the influence of different occlusal contacts in a superior pre-molar structure using Finite Element Analysis. <strong>Material and Methods:</strong> A three-dimensional model of a superior pre-molar was designed to simulate three occlusion situations, namely central occlusion and two types of lateral occlusion contacts. The model presents enamel, dentin, a periodontal ligament and a fixation cylinder separately. All materials were considered isotropic, linear and homogeneous, and the contacts of each structure were perfectly bonded. On analysis software, a load was applied to an occlusal surface at 40° to the long axis on lateral contacts, and directed to the long axis on central occlusion contact. <strong>Results:</strong> The results were obtained in stress maps and the maximum values were then plotted in table for quantitative comparison, with the enamel concentrating more stress than dentin and the occlusal contact presenting the worst biomechanical behavior. <strong>Conclusion: </strong>Within the limitations of this study, it is possible conclude that: eccentric contacts have higher potential to develop abfraction lesions on the cervical region of teeth, thus increasing the magnitude of tensile and shear stresses.</p><p><strong>Keywords</strong></p><p>Finite Elements Analysis, Abfraction; Stress distribution; Occlusion, Premolar.</p>

Liquid Flow Characteristics in Microchannels

2011 ◽  
Vol 130-134 ◽  
pp. 1484-1490
Author(s):  
Yan Feng Liu ◽  
Hong Wei Li ◽  
Jing Wei Zhang ◽  
Jin Xue
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Fluid Flow ◽  
Three Dimensional ◽  
Flow Characteristics ◽  
Simulation Methods ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Simulation Results ◽  
Poiseuille Number

A three-dimensional model was developed to simulate the laminar flow and convective heat transfer in rectangular silicon microchannels，which have hydraulic diameter of 95.3，92.3 ,85.8 , 80 and 75μm respectively．The rationality of the simulation methods and results were validated by comparing with experimental data. The simulation results indicate that the aspect ratio has a significant impact on the Poiseuille number. Conventional fluid flow theory is fit for researching the fluid flow in microchannels, Po is a constant that is not dependent on the Reynolds number.

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