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Online since: June 2012
Authors: Chong Zhi Mao, Lei He, Qian Jian Guo
Numerical simulation.
The start-up period of honeycomb was simulated by means of computational fluid dynamics (CFD) software; the outlet temperature were obtained.
Simulation model In the numerical simulation the ceramic honeycomb is square channel, of which cross-section is shown in Fig.1.
Results and analysis For a 3-D numerical simulation model, the structure and meshes were constructed by GAMBIT, and then numerical solution was obtained from the commercially available CFD code FLUENT to investigate the thermal dynamic behavior of the honeycomb regenerator starting-up process.
In this simulation, the switching time is 30s, namely, one cycle time is 60s.
The start-up period of honeycomb was simulated by means of computational fluid dynamics (CFD) software; the outlet temperature were obtained.
Simulation model In the numerical simulation the ceramic honeycomb is square channel, of which cross-section is shown in Fig.1.
Results and analysis For a 3-D numerical simulation model, the structure and meshes were constructed by GAMBIT, and then numerical solution was obtained from the commercially available CFD code FLUENT to investigate the thermal dynamic behavior of the honeycomb regenerator starting-up process.
In this simulation, the switching time is 30s, namely, one cycle time is 60s.
Online since: August 2022
Authors: Nívea Gomes Nascimento de Oliveira, Hortência Luma Fernandes Magalhães, Ricardo Soares Gomez, Daniel César M. Cavalcante, A. Santos Pereira, Guilherme Luiz Oliveira Neto, Severino Rodrigues Farias Neto, Amanda K.F. Abreu, Arthur G.F. Almeida, Sirlene A. Nunes
To achieve the objectives, computational fluid dynamics (CFD) and the Ansys CFD® software were used.
Consisting of 337,360 hexahedral elements, the computational mesh was built using the Ansys ICEM CFD® software.
Experimental and simulation of a novel hydrocyclone-tubular membrane as overflow pipe.
Lead/air separation process using cyclonic separator: modeling and simulation.
Computational Fluid Dynamics Simulation of Membrane Separation Processes.
Consisting of 337,360 hexahedral elements, the computational mesh was built using the Ansys ICEM CFD® software.
Experimental and simulation of a novel hydrocyclone-tubular membrane as overflow pipe.
Lead/air separation process using cyclonic separator: modeling and simulation.
Computational Fluid Dynamics Simulation of Membrane Separation Processes.
Online since: September 2014
Authors: Ismail Kashkoush, Jennifer Rieker, Gim Chen, Dennis Nemeth
With increasing numbers of MEMS applications, interest has grown in recent years for process modelling, simulation and software tools useful for the prediction of etched surface profiles [4-6].
Computational Fluid Dynamics (CFD), Theory vs.
To better understand the fluid dynamics within the cavities, CFD calculations were performed based on the current test setup.
( b ) (c ) (a ) Figure 7: CFD model for current test setup: a) schematic of possible flows, b) 300µm etch depth and c) 450µm etch depth Results on actual test wafers however, show a clear difference in appearance as the etch depth increases.
These results differ from the CFD model and emphasize the dynamic nature of the flow inside these types of structures.
Computational Fluid Dynamics (CFD), Theory vs.
To better understand the fluid dynamics within the cavities, CFD calculations were performed based on the current test setup.
( b ) (c ) (a ) Figure 7: CFD model for current test setup: a) schematic of possible flows, b) 300µm etch depth and c) 450µm etch depth Results on actual test wafers however, show a clear difference in appearance as the etch depth increases.
These results differ from the CFD model and emphasize the dynamic nature of the flow inside these types of structures.
Online since: December 2014
Authors: Hui Min Zhang, Hui Liang Liao
Structure optimization of open turbine type agitator
Huimin Zhang1,a*, Huiliang Liao2,b*
1,2School of Mechanical Engineering, Shanghai Institute of Technology, Shanghai 201418 China
azhanghm@sit.edu.cn, b18621527191@163.com
Keywords:open turbine type agitator; numerical simulation; optimized; PIV experiments
Abstract:Regarding open turbine type agitator, CFD method was used to simulate the mixing flow field with different number of blades, different blade angles and different ratio of blade lengths and diameters.
Numerical simulations are verified by PIV experiments.
Yuan Zuqiang[7] used CFD to calculate the flow field in the agitated vessel of open turbine type three-blade propeller and optimized the bottom clearance for installation and diameter of propeller through the observation of flow field under different settings which agree with the empirical value.
(a) Experimental streamlines (b) streamlines of simulation (c) diagram of mean velocity Fig.3 Streamlines of experiment and simulation, diagram of mean velocity From the comparison of the results of PIV experiment and Fluent numerical simulation, both the swirl position and the flow pattern are basically the same.
It turns out that the PIV experiment verifies the correctness of the numerical simulation, and the selected MRF model conforms to the reality.
Numerical simulations are verified by PIV experiments.
Yuan Zuqiang[7] used CFD to calculate the flow field in the agitated vessel of open turbine type three-blade propeller and optimized the bottom clearance for installation and diameter of propeller through the observation of flow field under different settings which agree with the empirical value.
(a) Experimental streamlines (b) streamlines of simulation (c) diagram of mean velocity Fig.3 Streamlines of experiment and simulation, diagram of mean velocity From the comparison of the results of PIV experiment and Fluent numerical simulation, both the swirl position and the flow pattern are basically the same.
It turns out that the PIV experiment verifies the correctness of the numerical simulation, and the selected MRF model conforms to the reality.
Online since: March 2011
Authors: Yong Xue Zhang, Zhi Cheng Shi, Chang Liu, Chan Guo
In this study, CFD software FLUENT is used to solve the governing equations.
Comparison between LDV experiment and numerical simulation It is the same flow rate both in the numerical simulation and in the experiment to make sure the reliability of the comparison between LDV experiment and numerical simulation.
Table 1 shows the comparison between LDV experiment and numerical simulation.
[08] Wilcox D C: Turbulence Modeling for CFD.Second Edition.
[09] Fujun Wang: Computational Fluid Dynamics - Principle and Application of CFD Software (Tsinghua University Press, 2004)
Comparison between LDV experiment and numerical simulation It is the same flow rate both in the numerical simulation and in the experiment to make sure the reliability of the comparison between LDV experiment and numerical simulation.
Table 1 shows the comparison between LDV experiment and numerical simulation.
[08] Wilcox D C: Turbulence Modeling for CFD.Second Edition.
[09] Fujun Wang: Computational Fluid Dynamics - Principle and Application of CFD Software (Tsinghua University Press, 2004)
Online since: June 2014
Authors: Xuan Ya Liu, Xiao Yuan Xu, Nian Hao Yu, Hong Ya Zhu, Chao Ji
The simulation scenario of leakage and diffusion assumes that LNG transport ships had an accident on the sea.
Gavelli [14] (2011) simulated the process of deflagration of nature gas when LNG loaded on the transport ship by using CFD software FLACS .Edward Bullister [15]simulated the Falcon text and indicated that it was feasible to utilize CFD software with suitable coefficient and boundary conditions to simulate the diffusion process of LNG.
Research of LNG focused on simulation and risk assessment in china, Qin Huang from Nanjing university of technology analyzed different models for LNG leakage simulation and compared foreign experimental date with simulated result.
Many experimental data and images obtained by experiments provided important materials for simulation study.
Many scientific problems such as RPT, the formation conditions of the pool fire are not intensive studied. 3, With the maturation of the CFD technology, Experts and scholars have carried out some researches of LNG through simulation now.
Gavelli [14] (2011) simulated the process of deflagration of nature gas when LNG loaded on the transport ship by using CFD software FLACS .Edward Bullister [15]simulated the Falcon text and indicated that it was feasible to utilize CFD software with suitable coefficient and boundary conditions to simulate the diffusion process of LNG.
Research of LNG focused on simulation and risk assessment in china, Qin Huang from Nanjing university of technology analyzed different models for LNG leakage simulation and compared foreign experimental date with simulated result.
Many experimental data and images obtained by experiments provided important materials for simulation study.
Many scientific problems such as RPT, the formation conditions of the pool fire are not intensive studied. 3, With the maturation of the CFD technology, Experts and scholars have carried out some researches of LNG through simulation now.
Online since: June 2014
Authors: Tao Li, Xiao Yu Jia
Through the indoor temperature, meteorological data, walls, roof, vent, vent and other structural elements, air conditioning load simulation.
Fig.2 Energy consumption simulation-Jin Yule residential area This Fig.2 chart displays average and total simulation data for the current building.To study the building of the year temperature,heat gains and energy consumption,the first chart shows room electricity and heating（gas）with the trend of the month.the second shows the temperature trends over the month, the third shows a thermal equilibrium with the changing trend of month. 3.Heat load data If the user can define in less than 1 hours of time step, using integrated synchronous load / system / device simulation method, heat balance method was used to simulate the load, muti-regional air flow, thermal comfort and photovoltaic system.
Wind field simulation, the indoor air quality analysis software is not limited to outdoor, it can help us to the outdoor heat simulation analysis, considering the HVAC systems Fig.4, solar radiation, surface structure on the indoor thermal environment simulation analysis of the influence of double glass curtain wall, inner heat flow analysis, environment on human comfort simulation.
Fig.4 CFD-Jin Yule residential area Fig.5 The amount of sunlight-Jin Yule residential area 5.The lighting calculation and report The amount of sunlight on the lighting control system model of computation, save electrical lighting.
Conclusion In this paper, through analyzing the simulation method of environmental performance of building systems, combining Jin Yule residential building as an example, through the construction of the environment simulation, performance prediction after the completion of the construction environment, emphasizes significance to the further study on the construction of the building environment performance.
Fig.2 Energy consumption simulation-Jin Yule residential area This Fig.2 chart displays average and total simulation data for the current building.To study the building of the year temperature,heat gains and energy consumption,the first chart shows room electricity and heating（gas）with the trend of the month.the second shows the temperature trends over the month, the third shows a thermal equilibrium with the changing trend of month. 3.Heat load data If the user can define in less than 1 hours of time step, using integrated synchronous load / system / device simulation method, heat balance method was used to simulate the load, muti-regional air flow, thermal comfort and photovoltaic system.
Wind field simulation, the indoor air quality analysis software is not limited to outdoor, it can help us to the outdoor heat simulation analysis, considering the HVAC systems Fig.4, solar radiation, surface structure on the indoor thermal environment simulation analysis of the influence of double glass curtain wall, inner heat flow analysis, environment on human comfort simulation.
Fig.4 CFD-Jin Yule residential area Fig.5 The amount of sunlight-Jin Yule residential area 5.The lighting calculation and report The amount of sunlight on the lighting control system model of computation, save electrical lighting.
Conclusion In this paper, through analyzing the simulation method of environmental performance of building systems, combining Jin Yule residential building as an example, through the construction of the environment simulation, performance prediction after the completion of the construction environment, emphasizes significance to the further study on the construction of the building environment performance.
Online since: October 2010
Authors: Yong Qian Liu, Zi Chan Tian, Fen Hua Li, Jian Xing
In this study,
numerical simulations of the two-dimension hill over smooth and roof surface have been done using
three different turbulence model :standard k ε− model and other revised models ,and the simulation
results have been prepared with wind tunnel experiments ,in order to obtain the best turbulence model
.
Currently,the location of wind power plant or wind turbine is mostly selected by using standard linear model software WAsP.Now more and more designers of wind power plant find that WAsP software is not suitable for wind power plant over complex terrain.So calculated fluid dynamics(CFD)begins gradually to be applied in the research of complex wind power plant.CFD simulation can fully consider the impact of terrain,roughness and barrier on orographic wind,establish numerical wind tunnel test,and calculate the flow field of orographic wind.
This model is given by Ishihara and others in 2001 when they made wind tunnel test,figure 1 describes the length and the heigth of the hill clearly,then compares the result of the simulation with this test.The mesh generation is showm in figure 1(b),the mesh of the surface layer of the hill is refined.
2 shows the results abtained from the simulation of three models on the hill with smooth surface,figure 2 (a) expresses the distribution of standardized turbulent kinetic energy, (b) represents the distribution of the average wind speed vector,and part 1,2,3 are respectively corresponding to standard k ε− model,RNG k ε− model and realizable k ε− model;The value of standard k ε− model is much larger than that of RGN k ε− model and realizable k ε− model in the distribution of standardized turbulent kinetic energy 2 Hk u in the position of the hill top compared results of three models.
The simulated results of realizable kε− model Fig. 3 shows the results abtained from the simulation of three models on the hill with rough surface,obviously, standardized turbulent kinetic energy 2 Hk u is in the position of the hill top,and the value of standard k ε− model is much larger than that of RNG k ε− model and realizable k ε− model;In the flow region in front of the hill,when 11.25 / 0X H − < < ,the standardized value of k abtained from RNG k ε− model is more close to testing value,the standard k ε− model and the realizable k ε− model both overestimate the value of k in this region,but after pasing the hill top,RNG k ε− model underestimates the value of k,however the value of realizable k ε− model and test is most approach.
Currently,the location of wind power plant or wind turbine is mostly selected by using standard linear model software WAsP.Now more and more designers of wind power plant find that WAsP software is not suitable for wind power plant over complex terrain.So calculated fluid dynamics(CFD)begins gradually to be applied in the research of complex wind power plant.CFD simulation can fully consider the impact of terrain,roughness and barrier on orographic wind,establish numerical wind tunnel test,and calculate the flow field of orographic wind.
This model is given by Ishihara and others in 2001 when they made wind tunnel test,figure 1 describes the length and the heigth of the hill clearly,then compares the result of the simulation with this test.The mesh generation is showm in figure 1(b),the mesh of the surface layer of the hill is refined.
2 shows the results abtained from the simulation of three models on the hill with smooth surface,figure 2 (a) expresses the distribution of standardized turbulent kinetic energy, (b) represents the distribution of the average wind speed vector,and part 1,2,3 are respectively corresponding to standard k ε− model,RNG k ε− model and realizable k ε− model;The value of standard k ε− model is much larger than that of RGN k ε− model and realizable k ε− model in the distribution of standardized turbulent kinetic energy 2 Hk u in the position of the hill top compared results of three models.
The simulated results of realizable kε− model Fig. 3 shows the results abtained from the simulation of three models on the hill with rough surface,obviously, standardized turbulent kinetic energy 2 Hk u is in the position of the hill top,and the value of standard k ε− model is much larger than that of RNG k ε− model and realizable k ε− model;In the flow region in front of the hill,when 11.25 / 0X H − < < ,the standardized value of k abtained from RNG k ε− model is more close to testing value,the standard k ε− model and the realizable k ε− model both overestimate the value of k in this region,but after pasing the hill top,RNG k ε− model underestimates the value of k,however the value of realizable k ε− model and test is most approach.
Online since: January 2012
Authors: Tao Lu, Kui Sheng Wang, Yong Wei Wang
Keywords: Large eddy simulation, turbulent flow, Tee, periodic porous media
Abstract.
Many turbulence models are used to numerical simulate the turbulent flow in porous media, such as direct numerical simulations (DNS), Reynolds averaged Navier–Stokes (RANS) equations and large eddy simulation (LES).
The present paper presents numerical simulations of the fluid turbulent flow at various inlet velocities in a Tee junction filled with periodic sintered copper spheres using LES and the sub-grid scale Smagorinsky–Lilly model on the commercial computational fluid dynamics (CFD) software FLUENT.
Fig. 1 Schematic of a Tee junction filed with periodic sintered copper spheres The three-dimensional turbulent flow in a Tee junction was solved using the CFD software FLUENT.
The water properties were assumed to be constant in the simulations.
Many turbulence models are used to numerical simulate the turbulent flow in porous media, such as direct numerical simulations (DNS), Reynolds averaged Navier–Stokes (RANS) equations and large eddy simulation (LES).
The present paper presents numerical simulations of the fluid turbulent flow at various inlet velocities in a Tee junction filled with periodic sintered copper spheres using LES and the sub-grid scale Smagorinsky–Lilly model on the commercial computational fluid dynamics (CFD) software FLUENT.
Fig. 1 Schematic of a Tee junction filed with periodic sintered copper spheres The three-dimensional turbulent flow in a Tee junction was solved using the CFD software FLUENT.
The water properties were assumed to be constant in the simulations.
Online since: May 2014
Authors: Bai Jing Qiu, Bei Fen Zhu, Jing Ma, Run Yan
To obtain the design criterion ofcurve regression equations and area ratio,Wan Peisun conducted tests on the jet-mixing apparatus and discussed the relationship between its structure parameters[2].He Peijie chose different jet nozzle diameters and different jet nozzle distances and some other parameters to determine the pressure ratio and the flow ratio of jet-mixing apparatus[3].To analyze and compare the mixing performance of different kinds of jet mixing apparatus, Xu Youlin designed 4 forms of jet-mixing apparatus and carried out numerical simulation by using CFD software Fluent flow[4].Meanwhile.Qiu Baijing studied pipe distance, area ratio and inlet angle on the effects of mixing performance of the mixing device by CFD, he obtained some rules between the three structural parameters and the jet mixing properties[5].
At present, the research on jet mixing was limited to the flow field simulation of jet mixing apparatus and experimental analysis, but the jet-mixing device and spray system to integrate a large system for the research didn’t be taken.Therefore, this text studies working state of jet mixing apparatus used in spray system based on the bench test. 1 Working state of jet-mixing apparatus 1.1 The structure and parameters of jet-mixing apparatus A jet-mixing apparatus is mainly composed of jet nozzle, medicine sucking mouth, suction chamber, mixing tube and diffusion tube, its structure is schematically shown in figure1.And the structural parameters of jet-mixing apparatus could be divided into fixed parameters and variable parameters, fixed parameter is a constant parameter in the optimization design and variable parameter refers to changing parameters values in order to explore an optimized parameter in the effects of flow jet to jet-mixing apparatus in simulation design.
The apparatus may appears reflux and cavitation that are thought as failed condition, to avoid back flow and cavitation state, the current research on reflux state of jet-mixing apparatus is less, this paper will study the working state of the jet-mixing apparatus from numerical simulation and experimental study. 2 Bench test 2.1 The bench test device The main parts of the test device are: online mixing test platform, it consists of dynamic liquid pump, water tank, pesticide tank, jet mixer, spraying system and the measuring elements, the structure and the test bench of online automatic mixing test platform are both shown in figure 2.
[4] Xu Youlin,Zhou Fengfang,Guo Jingkun.Flow Field Simulation of Chemical Mixing Process for Direct Injection System based on CFD[C].2008:ASABE International Meeting,Rhode [5] Qiu Baijing,Xu Xichao,Yang Ning.The simulation analysis of the influence of structure paraments on the mixing performance of jet mixing device[J],Transaction of the Chinese Society for Agricultural Machinery,2011, 42(6): 172~174.
At present, the research on jet mixing was limited to the flow field simulation of jet mixing apparatus and experimental analysis, but the jet-mixing device and spray system to integrate a large system for the research didn’t be taken.Therefore, this text studies working state of jet mixing apparatus used in spray system based on the bench test. 1 Working state of jet-mixing apparatus 1.1 The structure and parameters of jet-mixing apparatus A jet-mixing apparatus is mainly composed of jet nozzle, medicine sucking mouth, suction chamber, mixing tube and diffusion tube, its structure is schematically shown in figure1.And the structural parameters of jet-mixing apparatus could be divided into fixed parameters and variable parameters, fixed parameter is a constant parameter in the optimization design and variable parameter refers to changing parameters values in order to explore an optimized parameter in the effects of flow jet to jet-mixing apparatus in simulation design.
The apparatus may appears reflux and cavitation that are thought as failed condition, to avoid back flow and cavitation state, the current research on reflux state of jet-mixing apparatus is less, this paper will study the working state of the jet-mixing apparatus from numerical simulation and experimental study. 2 Bench test 2.1 The bench test device The main parts of the test device are: online mixing test platform, it consists of dynamic liquid pump, water tank, pesticide tank, jet mixer, spraying system and the measuring elements, the structure and the test bench of online automatic mixing test platform are both shown in figure 2.
[4] Xu Youlin,Zhou Fengfang,Guo Jingkun.Flow Field Simulation of Chemical Mixing Process for Direct Injection System based on CFD[C].2008:ASABE International Meeting,Rhode [5] Qiu Baijing,Xu Xichao,Yang Ning.The simulation analysis of the influence of structure paraments on the mixing performance of jet mixing device[J],Transaction of the Chinese Society for Agricultural Machinery,2011, 42(6): 172~174.