Numerical Simulation of Diffusion of UDMH in Confined Space

2013 ◽  
Vol 295-298 ◽  
pp. 586-589
Author(s):  
Jia Zhao Chen ◽  
Chao Ning ◽  
Yu Xiang Zhang
Keyword(s):  
Numerical Simulation ◽  
Concentration Distribution ◽  
Geometric Model ◽  
Polluted Area ◽  
Confined Space ◽  
Gas Concentration ◽  
Diffusion Pattern ◽  
Toxic Gas ◽  
3D Geometric Model ◽  
And Diffusion

In order to study the diffusion pattern of Unsymmetrical Dimethyl Hydrazine (UDMH) in a confined space, a 3D geometric model of cylindrical space with a column obstacle in the center was built and diffusion of UDMH in the space was simulated by using FLUENT. The gas concentration distribution in the space was gained at different moments, and the polluted area with concentration above 0.5ppm was focused on. The simulation result suggests that the toxic gas is mainly concentrated in an area about 1m above the bottom of the space, and ventilation can effectively reduce the hazard time and continuous expansion of polluted area.

Dissolved Oxygen Convection and Diffusion Numerical Simulation of Water and Air Mixture Flow in Circular Pipe

2011 ◽  
Vol 383-390 ◽  
pp. 6651-6656
Author(s):  
Ze Gao Yin ◽  
Xian Wei Cao ◽  
Dong Sheng Cheng ◽  
Le Wang
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Dissolved Oxygen ◽  
Oxygen Concentration ◽  
Pipe Flow ◽  
Concentration Distribution ◽  
Dissolved Oxygen Concentration ◽  
Mixture Flow ◽  
Velocity Pressure ◽  
And Diffusion

In Fluent, the 3-D RNG k–ε mathematical model is employed to compute water and air mixture pipe flow. The dissolved oxygen convectionaεnd diffusion model is established to simulate the concentration distribution of dissolved oxygen with user defined scalar method. Velocity, pressure and dissolved oxygen concentration are computed. Then, dissolved oxygen concentration and pressure are compared with the data of physical model, and they agree with each other approximately, showing it is valid and reliable to compute the mixture pipe flow and dissolved oxygen concentration with the model .Furthermore, under a specific condition, velocity, pressure and dissolved oxygen concentration of water and air mixture pipe flow are computed and their characteristics are analyzed.

Numerical Simulation of Corrugated Depth on the Performance of Plate Heat Exchanger

2013 ◽  
Vol 860-863 ◽  
pp. 696-699 ◽  
Author(s):  
Yu Han Zhao ◽  
Yi Fan Wu ◽  
Hai Jin Cheng ◽  
Guo Lei Zhu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Heat Exchanger ◽  
Geometric Model ◽  
Plate Heat Exchanger ◽  
Computational Domain ◽  
Plate Heat ◽  
3D Geometric Model

In this paper the numerical simulation is performed by using the CFD soft FLUENT. A 3D geometric model is established and whose mesh is generated. The fields of the temperature, pressure and velocity in the computational domain are simulated. And the effect of the corrugation depth on the heat transfer and flow is analyzed.

Hoist Sheave Structure Optimization and Lightweight

2015 ◽  
Vol 741 ◽  
pp. 133-137
Author(s):  
Xian Zhao Jia ◽  
Yong Fei Wang
Keyword(s):  
Working Condition ◽  
Geometric Model ◽  
Structure Optimization ◽  
Element Model ◽  
Stiffened Plate ◽  
Optimal Result ◽  
Ansys Software ◽  
Table Analysis ◽  
3D Geometric Model ◽  
Relational Table

To ensure wheel body of the hoisting sheave strength and stability condition. For the purpose of wheel body lightweighting. There are two schemes to reduce body weight.Reduce the spokes at the same time increase the ring stiffened plate, and reduce the spokes at the same time change the spokes width and thickness.The wheel body was established based on Pro/E 3D geometric model. Import the mesh in the Workbench of ANSYS software for finite element model. Statics analysis to select the optimized scheme. Establish a hoisting sheave wheel body under the actual working condition of widening the width - deformation - wheel weight relational table. Analysis to lightweight at the same time ensure that stiffness of wheel,then it can obtaine the optimal result.

scholarly journals Numerical Simulation and Experimental Study on Axial Stiffness and Stress Deformation of the Braided Corrugated Hose

2021 ◽  
Vol 11 (10) ◽  
pp. 4709
Author(s):  
Dacheng Huang ◽  
Jianrun Zhang
Keyword(s):  
Numerical Simulation ◽  
Geometric Model ◽  
Equivalent Stress ◽  
Element Model ◽  
Maximum Error ◽  
Structural Features ◽  
Axial Stiffness ◽  
Frictional Stress ◽  
Maximum Equivalent Stress ◽  
Simulation Results

To explore the mechanical properties of the braided corrugated hose, the space curve parametric equation of the braided tube is deduced, specific to the structural features of the braided tube. On this basis, the equivalent braided tube model is proposed based on the same axial stiffness in order to improve the calculational efficiency. The geometric model and the Finite Element Model of the DN25 braided corrugated hose is established. The numerical simulation results are analyzed, and the distribution of the equivalent stress and frictional stress is discussed. The maximum equivalent stress of the braided corrugated hose occurs at the braided tube, with the value of 903MPa. The maximum equivalent stress of the bellows occurs at the area in contact with the braided tube, with the value of 314MPa. The maximum frictional stress between the bellows and the braided tube is 88.46MPa. The tensile experiment of the DN25 braided corrugated hose is performed. The simulation results are in good agreement with test data, with a maximum error of 9.4%, verifying the rationality of the model. The study is helpful to the research of the axial stiffness of the braided corrugated hose and provides the base for wear and life studies on the braided corrugated hose.

Gas Concentration Distribution Law in the Roadway after Coal and Gas Outburst

2015 ◽  
Vol 713-715 ◽  
pp. 314-318
Author(s):  
Chun Li Yang ◽  
Yi Liang Zhao ◽  
Xiang Chun Li ◽  
Yang Yang Meng ◽  
Fei Fei Zhu
Keyword(s):  
Concentration Distribution ◽  
Correlation Coefficients ◽  
Coal And Gas Outburst ◽  
Gas Emission ◽  
Distribution Law ◽  
Gas Concentration ◽  
Research Results ◽  
Gas Outburst ◽  
Whole Process ◽  
Secondary Disasters

Gas emission happens after coal and gas outburst, and it could cause secondary disasters in the roadway. Therefore it is necessary to research gas concentration distribution law in the roadway after coal and gas outburst, and theoretical basis for avoiding the occurrence of secondary disasters could be provided. Based on the above, Fluent is used to simulate gas concentration distribution law in the roadway during outburst. The research results show that gas velocity of the initial stage is larger in the whole process of gas outburst and gas emission impacts opposite walls in the form of jet in the roadway intersection. The flow changes direction and moves along the main airway and return airway. It produces countercurrent along the main airway. Because the pressure in the main airway is high, gas migration velocity becomes zero after a certain distance and is "back" to return airway. The higher the outburst velocity is, the longer the flow length is. Gas concentration variation with two kinds of different outburst intensities and position are regressed and it shows that correlation coefficients of power function are the highest. The research results have a certain theoretical value to prevent the occurrence of secondary disasters after coal and gas outburst.

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