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Flow Field and Temperature Field in GaN-MOCVD Reactor Based on Computational Fluid Dynamics Modeling 被引量:1
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作者 梅书哲 王权 +8 位作者 郝美兰 徐健凯 肖红领 冯春 姜丽娟 王晓亮 刘峰奇 徐现刚 王占国 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第9期82-86,共5页
Metal organic chenlical vapor deposition (AIOCVD) growth systems arc one of the. main types of equipment used for growing single crystal materials, such as GaN. To obtain fihn epitaxial materials with uniform perfor... Metal organic chenlical vapor deposition (AIOCVD) growth systems arc one of the. main types of equipment used for growing single crystal materials, such as GaN. To obtain fihn epitaxial materials with uniform performanee, the flow field and ternperature field in a GaN-MOCVD reactor are investigated by modeling and simulating. To make the simulation results more consistent with the actual situation, the gases in the reactor are considered to be compressible, making it possible to investigate the distributions of gas density and pressure in the reactor. The computational fluid dynamics method is used to stud,v the effects of inlet gas flow velocity, pressure in the reactor, rotational speed of graphite susceptor, and gases used in the growth, which has great guiding~ significance for the growth of GaN fihn materials. 展开更多
关键词 MOCVD Flow Field and Temperature Field in GaN-MOCVD Reactor Based on Computational fluid dynamics modeling GAN
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A Finite-Mode Model of Ideal Fluid Dynamics on the 2-Sphere
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《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1997年第3期68-81,共14页
AFinite-ModeModelofIdealFluidDynamicsonthe2-SphereWeiMozhengCRCforSouthernHemisphereMeteorologyCSIRODivision... AFinite-ModeModelofIdealFluidDynamicsonthe2-SphereWeiMozhengCRCforSouthernHemisphereMeteorologyCSIRODivisionofAtmosphericRese... 展开更多
关键词 A Finite-Mode model of Ideal fluid dynamics on the 2-Sphere
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The State Key Laboratory of Numerical Modelling for Atmospheric Science and Geophysical Fluid Dynamics 被引量:1
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《Bulletin of the Chinese Academy of Sciences》 2000年第4期233-235,共3页
The State Key Laboratory of Numerical Modelling for Atmospheric Science and Geophysical Fluid Dynamics (LASG) was established in 1985. It was considered an Excellent Opening Laboratory in the national assessment organ... The State Key Laboratory of Numerical Modelling for Atmospheric Science and Geophysical Fluid Dynamics (LASG) was established in 1985. It was considered an Excellent Opening Laboratory in the national assessment organized by the former State Science and Technology Committee (now the Ministry of Science and Technology) in 1988. Because of this, LASG was upgraded to a State Key Laboratory in 1989. It won the honor of "Excellent 展开更多
关键词 The State Key Laboratory of Numerical modelling for Atmospheric Science and Geophysical fluid dynamics
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State Key Lab of Numerical Modeling for Atmospheric Science and Geophysical Fluid Dynamics
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《Bulletin of the Chinese Academy of Sciences》 2000年第4期2-2,共1页
The State Key Laboratory of Numerical Modeling for Atmospheric Science and Geophysical Fluid Dynamics (LASG) was set up as early as in 1985. It has been appraised as an Excellent State Key Lab in each of the three nat... The State Key Laboratory of Numerical Modeling for Atmospheric Science and Geophysical Fluid Dynamics (LASG) was set up as early as in 1985. It has been appraised as an Excellent State Key Lab in each of the three national assessments organized by State Economic Planning Commission, National Natural Science Foundation (NSFC) and the Ministry of Science and Technology (MOST) in 1991, 1996 and 2000, respectively. 展开更多
关键词 LAB State Key Lab of Numerical modeling for Atmospheric Science and Geophysical fluid dynamics
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A theoretical study of the signal enhancement mechanism of coaxial DP-LIBS
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作者 宋震 王俊霄 +11 位作者 王钢 张雷 王树青 张婉飞 马晓飞 刘珍荣 罗学彬 马维光 叶泽甫 朱竹君 尹王保 贾锁堂 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第5期156-164,共9页
In the field of dual-pulse laser-induced breakdown spectroscopy(DP-LIBS)research,the pursuit of methods for determining pulse intervals and other parameters quickly and conveniently in order to achieve optimal spectra... In the field of dual-pulse laser-induced breakdown spectroscopy(DP-LIBS)research,the pursuit of methods for determining pulse intervals and other parameters quickly and conveniently in order to achieve optimal spectral signal enhancement is paramount.To aid researchers in identification of optimal signal enhancement conditions and more accurate interpretation of the underlying signal enhancement mechanisms,theoretical simulations of the spatiotemporal processes of coaxial DP-LIBS-induced plasma have been established in this work.Using a model based on laser ablation and two-dimensional axisymmetric fluid dynamics,plasma evolutions during aluminum–magnesium alloy laser ablation under single-pulse and coaxial dualpulse excitations have been simulated.The influences of factors,such as delay time,laser fluence,plasma temperature,and particle number density,on the DP-LIBS spectral signals are investigated.Under pulse intervals ranging from 50 to 1500 ns,the time evolutions of spectral line intensity,dual-pulse emission enhancement relative to the single-pulse results,laser irradiance,spatial distribution of plasma temperature and species number density,as well as laser irradiance shielded by plasma have been obtained.The study indicates that the main reason behind the radiation signal enhancement in coaxial DP-LIBS-induced plasma is attributed to the increased species number density and plasma temperature caused by the second laser,and it is inferred that the shielding effect of the plasma mainly occurs in the boundary layer of the stagnation point flow over the target surface.This research provides a theoretical basis for experimental research,parameter optimization,and signal enhancement tracing in DP-LIBS. 展开更多
关键词 laser-induced plasma radiation fluid dynamics model double pulse laser-induced breakdown spectroscopy(DP-LIBS) laser ablation signal enhancement mechanism
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Modeling the effects of mechanical parameters on the hydrodynamic behavior of vertical current classifiers 被引量:3
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作者 Arabzadeh Jarkani Soroush Khoshdast Hamid +1 位作者 Shariat Elaheh Sam Abbas 《International Journal of Mining Science and Technology》 SCIE EI 2014年第1期123-127,共5页
This study modeled the effects of structural and dimensional manipulations on hydrodynamic behavior of a bench vertical current classifier. Computational fluid dynamics (CFD) approach was used as modeling method, an... This study modeled the effects of structural and dimensional manipulations on hydrodynamic behavior of a bench vertical current classifier. Computational fluid dynamics (CFD) approach was used as modeling method, and turbulent intensity and fluid velocity were applied as system responses to predict the over- flow cut size variations. These investigations showed that cut size would decrease by increasing diameter and height of the separation column and cone section depth, due to the decrease of turbulent intensity and fluid velocity. As the size of discharge gate increases, the overflow cut-size would decrease due to freely fluid stream out of the column. The overflow cut-size was significantly increased in downward fed classifier compared to that fed by upward fluid stream. In addition, reforming the shape of angular overflow outlet's weir into the curved form prevented stream inside returning and consequently unselec- tire cut-size decreasing. 展开更多
关键词 Hydraulic classifier modeling Computational fluid dynamic Cut size
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AXIAL HEAT CONDUCTION MODEL TO PREDICT MAXIMUM HEAT REMOVE OF MINIATURE HEAT PIPE BASED ON GREY MODEL THEORY 被引量:3
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作者 Tsai Mengchang Chang Shinhsing Kang Shungwen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2005年第4期477-481,共5页
Computer chip is always accompanied by the increase of heat dissipation and miniaturization. The miniature heat pipes are widely used in notebook computer to resolve the heat dissipation problems. Maximum heat removed... Computer chip is always accompanied by the increase of heat dissipation and miniaturization. The miniature heat pipes are widely used in notebook computer to resolve the heat dissipation problems. Maximum heat removed model of miniature heat pipes building by grey model is presented. In order to know the foundation for modeling, the smooth grade of error examination is inquired and the accuracy of grey relational grade is verified. The model can be used to select a suitable heat pipes to solve electric heat problems in the future. Final results show that the grey model only needs four experiment data and its error value is less than 10%, further, it is better than computational fluid dynamics (CFD) model. 展开更多
关键词 Maximum heat removed model Miniature heat pipe Grey model theory Computational fluid dynamics (CFD) Grey relational grade
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Using computational fluid dynamic simulation with Flow-3D to reveal the origin of the mushroom stone in the Xiqiao Mountain of Guangdong, China
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作者 LI Jian-cheng WANG Wei +5 位作者 ZHENG Yan-ming WEN Xiao-hao FENG Jing SHENG Li WANG Chen QIU Ming-kun 《Journal of Mountain Science》 SCIE CSCD 2022年第1期1-15,共15页
Mushroom shaped rocks are not uncommon in nature, but their origin is often misunderstood because they can be formed by different natural forces. A huge mushroom stone in a stream valley of the Xiqiao Mountain of Guan... Mushroom shaped rocks are not uncommon in nature, but their origin is often misunderstood because they can be formed by different natural forces. A huge mushroom stone in a stream valley of the Xiqiao Mountain of Guangdong,China is widely believed to be formed through the way of stream water erosion. However, the result of the simulation performed with Flow-3 D in this study indicates that the mushroom shape of the rock could not have been sculpted by the flowing water erosion because the simulation result contradicts that of the field investigations:(1) the sediment brought by upstream flowing water tends to be deposited on the leeward side of the flowing water preventing the rock on this side form being eroded, but the narrowest part of the rock bottom is exactly located on this side of the rock and(2) the stream flow should erode the bed sediment and produce high abrasion on the rock surface on the upstream and lateral sides of the rock,respectively, but no abrasion marks are found on the same sides of the rock. Subsequent geological analyses in this study provide evidence that the narrow bottom of the mushroom stone was resulted from chemical and physical weathering happening within the sediment that used to deposit on the lee side of the stone. 展开更多
关键词 Mushroom Stone Computational fluid dynamics(CFD)model Mineralogical analysis Chemical weathering Xiqiao Mountain happening
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CFD modeling of a headbox with injecting dilution water in a central step diffusion tube
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作者 Xu Yang Jinsong Zeng +1 位作者 Kefu Chen Yucheng Feng 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第10期1313-1324,共12页
For engineering applications of water dilution controlling system,the fluid dynamics of a mixed flow was studied with computational fluid dynamics(CFD) simulations and self-designed experimental set-up.In order to exa... For engineering applications of water dilution controlling system,the fluid dynamics of a mixed flow was studied with computational fluid dynamics(CFD) simulations and self-designed experimental set-up.In order to examine the predictability of CFD model for the headbox in industrial scale,two pulp suspensions before mixing were treated as homogeneous flows separately.Standard k-ε turbulence models with the mass diffusion in turbulent flows-species transport approach were applied in the simulations.A numerical simulation of this headbox model was analyzed with semi-implicit method for pressure linked equations scheme with pressure–velocity coupling.Results show that the model can predict hydrodynamic characteristics of headbox with injecting dilution water in a central diffusion tube,and the distribution of water content at the outlet of the slice lip is ideally normal at different speeds. 展开更多
关键词 Computational fluid dynamics Headbox Turbulence model Species transport Pulp suspension
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Experimental and numerical modeling of carbonized biomass gasification: A critical review
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作者 Kannie Winston Kuttin Haowen Yu +4 位作者 Mingming Yang Lu Ding Xueli Chen Guangsuo Yu Fuchen Wang 《Green Carbon》 2024年第2期176-196,共21页
Gasification is one of the most significant and well-researched pathways to produce energy from biomass among the different options available.It is a conversion through thermo-chemical process that takes place within ... Gasification is one of the most significant and well-researched pathways to produce energy from biomass among the different options available.It is a conversion through thermo-chemical process that takes place within a gasifier,with interconnected factors that have an impact on how well the gasifier works.Gasification of carbonized biomass,which has a variety of effects on both the gasification process and the final product,is a significant method of producing energy from raw biomass that contains a lot of moisture or has non-homogeneous morphology.Although carbonized biomass has the potential to eliminate or significantly reduce tar formation,which is the most difficult aspect of biomass gasifier design and operation,it has not received the attention it merits even though gasification of biomass is a well-known conversion process with extensive research and development spanning all sectors of the process.This review gathers and analyzes the growing number of experimental and numerical modeling approaches in gasification of carbonized biomass based on exact conditions such as type of modeling considerations,feedstock,gasifier,and assessed parameters.The study also provides an overview of various models,such as equilibrium and kinetic rate models and numerical simulations of carbonized biomass gasification schemes based on computational fluid dynamics and Aspen Plus,while comparing the modeling approaches and results for each type of models that are described in the literature.Also,this review encompasses a broad variety of technologies,from laboratory reactors to industrial scale.Overall,this review offers a brief overview of the modeling decisions that must be taken at the beginning of a modeling research. 展开更多
关键词 Carbonized biomass GASIFICATION Thermodynamic model Kinetic model Computational fluid dynamics model
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Numerical simulation of laser-induced plasma in background gas considering multiple interaction processes
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作者 Junxiao WANG Lei ZHANG +11 位作者 Shuqing WANG Maogen SU Duixiong SUN Jianghua HAN Guofu XIA Chenzhong DONG Qi MIN Weiguang MA Lei DONG Wangbao YIN Liantuan XIAO Suotang JIA 《Plasma Science and Technology》 SCIE EI CAS CSCD 2021年第3期1-10,共10页
Laser-induced plasma is often produced in the presence of background gas,which causes some new physical processes.In this work,a two-dimensional axisymmetric radiation fluid dynamics model is used to numerically simul... Laser-induced plasma is often produced in the presence of background gas,which causes some new physical processes.In this work,a two-dimensional axisymmetric radiation fluid dynamics model is used to numerically simulate the expansion process of plasma under different pressures and gases,in which the multiple interaction processes of diffusion,viscosity and heat conduction between the laser ablated target vapor and the background gas are further considered,and the spatio-temporal evolutions of plasma parameters(species number density,expansion velocity,size and electron temperature)as well as the emission spectra are obtained.The consistency between the actual and simulated spectra of aluminum plasma in 1 atm argon verifies the correctness of the model and the numerical simulation,thus providing a refinement analysis method for the basic research of plasma expansion in gases and the application of laser-induced breakdown spectroscopy. 展开更多
关键词 laser-induced plasma radiation fluid dynamics model DIFFUSION VISCOSITY heat conduction
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Computational fluid dynamic modeling of gas flow characteristics of the high-power CW CO_2 laser 被引量:1
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作者 黄鸿雁 王又青 《Chinese Optics Letters》 SCIE EI CAS CSCD 2011年第1期60-63,共4页
To increase the photoelectronic conversion efficiency of the single discharge tube and to meet the requirements of the laser cutting system, optimization of the discharge tube structure and gas flow field is necessary... To increase the photoelectronic conversion efficiency of the single discharge tube and to meet the requirements of the laser cutting system, optimization of the discharge tube structure and gas flow field is necessary. We present a computational fluid dynamic model to predict the gas flow characteristics of high-power fast-axial flow CO2 laser. A set of differential equations is used to describe the operation of the laser. Gas flow characteristics, are calculated. The effects of gas velocity and turbulence intensity on discharge stability are studied. Computational results are compared with experimental values, and a good agreement is observed. The method presented and the results obtained can make the design process more efficient. 展开更多
关键词 FLOW Computational fluid dynamic modeling of gas flow characteristics of the high-power CW CO2 laser CO HIGH
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Complementarity of CFD,experimentation and reactor models for solving challenging fluidization problems 被引量:4
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作者 John R. Grace Tingwen Li 《Particuology》 SCIE EI CAS CSCD 2010年第6期498-500,共3页
Experimentalists, numerical modellers and reactor modellers need to work together, not only just for validation of numerical codes, but also to shed fundamental light on each other's problems and underlying assumptio... Experimentalists, numerical modellers and reactor modellers need to work together, not only just for validation of numerical codes, but also to shed fundamental light on each other's problems and underlying assumptions. Several examples are given, Experimental gas axial dispersion data provide a means of choosing the most appropriate boundary condition (no slip, partial slip or full slip) for particles at the wall of fluidized beds. CFD simulations help to identify how close "two-dimensional" experimental columns are to being truly two-dimensional and to representing three-dimensional columns. CFD also can be used to provide a more rational means of establishing assumptions needed in the modelling of two-phase fluidized bed reactors, for example how to deal with cases where there is a change in molar flow (and hence volumetric flow) as a result of chemical reactions. 展开更多
关键词 fluidization Mixing Computational fluid dynamics Wall slip Reactor modelling Volume change
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Computational Fluid Dynamics and Experimental Study of Lock-in Phenomenon in Vortex-Induced Motions of a Cell-Truss Spar 被引量:5
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作者 王颖 杨建民 吕海宁 《Journal of Shanghai Jiaotong university(Science)》 EI 2009年第6期757-762,共6页
Spar platforms could be subject to vortex-induced-motions(VIM) in certain current conditions.Lockin is a phenomenon which occurs in a range of reduced velocities in VIM.In this paper,a new concept of spar platform cal... Spar platforms could be subject to vortex-induced-motions(VIM) in certain current conditions.Lockin is a phenomenon which occurs in a range of reduced velocities in VIM.In this paper,a new concept of spar platform called cell-truss spar is studied using both computational fluid dynamics(CFD) and model test to investigate the VIM of the spar under different reduced velocities.The unique configuration of the cell-truss spar is carefully considered,and the unsteady flow around the spar is calculated and visualized in CFD simulations.A physical model with a scale ratio of 1:100 of the cell-truss spar is fabricated,and model tests are carried out in the current-generating ocean engineering basin.Many important parameters in VIM of the cell-truss spar are obtained,the occurrence of lock-in phenomenon is successfully simulated,and the mechanism and rules of lock-in are analyzed. 展开更多
关键词 SDar vortex-induced motions (VIM) lock in com gutational fluid dynamics (CFD) model test
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Computational fluid dynamics simulation of hydrodynamics in the riser of an external loop airlift reactor 被引量:6
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作者 Xuedong Jiang Ning Yang Bolun Yang 《Particuology》 SCIE EI CAS CSCD 2016年第4期95-101,共7页
Local hydrodynamics in the riser of an external loop airlift reactor (EL-ALR) are identified and the performances of three drag models are evaluated in computational fluid dynamics simulation. The simulation results... Local hydrodynamics in the riser of an external loop airlift reactor (EL-ALR) are identified and the performances of three drag models are evaluated in computational fluid dynamics simulation. The simulation results show that the Schiller-Naumann drag model underestimated the local gas holdup at lower superficial gas velocity whereas the Tomiyama drag model overestimated that at higher superficial gas velocity. By contrast, the dual-bubble-size (DBS)-local drag model gave more reasonable radial and axial distri-butions of gas holdup in all cases. The reason is that the DBS-local drag model gave correct values of the lumped parameter, i,e., the ratio of the drag coefficient to bubble diameter, for varying operating conditions and radial positions. This ratio is reasonably expected to decrease with increasing superficial gas velocity and be smaller in the center and larger near the wall. Only the DBS-local drag model correctly reproduced these trends. The radial profiles of the axial velocity of the liquid and gas predicted by the DBS-local model also agreed well with experimental data. 展开更多
关键词 Computational fluid dynamics External loop airlift reactor Drag model Gas holdup Mnltiscale Mesoscale
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Simulations of vertical jet penetration using a filtered two-fluid model in a gas-solid fluidized bed 被引量:2
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作者 Shuyan Wang Baoli Shao +5 位作者 Xiangyu Li Jian Zhao Lili Liu Yikun Liu gang Liu Qun Dong 《Particuology》 SCIE EI CAS CSCD 2017年第2期95-104,共10页
The influence of a vertical jet located at the distributor in a cylindrical fluidized bed on the flow behavior of gas and particles was predicted using a filtered two-fluid model proposed by Sundaresan and coworkers. ... The influence of a vertical jet located at the distributor in a cylindrical fluidized bed on the flow behavior of gas and particles was predicted using a filtered two-fluid model proposed by Sundaresan and coworkers. The distributions of volume fraction and the velocity of particles along the lateral direction were investigated for different jet velocities by analyzing the simulated results. The vertical jet penetration lengths at the different gas jet velocities have been obtained and compared with predictions derived from empirical correlations; the predicted air jet penetration length is discussed. Agreement between the numerical simulations and experimental results has been achieved. 展开更多
关键词 fluidized bed Vertical jet penetration Filtered model Computational fluid dynamics Numerical simulation
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Variation in pore distribution along sample length in sintered 7xxx aluminum alloy
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作者 Xi-ni YUAN S.M.AMINOSSADATI M.QIAN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第8期2019-2028,共10页
An experimental and computational fluid dynamics (CFD) numerical study of the sintering of an Al?7Zn?2.5Mg?1Cu alloy in flowing nitrogen was presented. Three rectangular bars with dimensions of 56 mm × 10 mm ... An experimental and computational fluid dynamics (CFD) numerical study of the sintering of an Al?7Zn?2.5Mg?1Cu alloy in flowing nitrogen was presented. Three rectangular bars with dimensions of 56 mm × 10 mm × 4.5 mm each, equally spaced 2 or 10 mm apart, were sintered in one batch at 620 °C for 40 min in a tube furnace. The pore distribution in the selected cross section of sintered samples was found to be dependent on the sample separation distance and the distance from the cross section examined to the sample end. A three-dimensional (3D) CFD model was developed to investigate the nitrogen gas behavior near each sintering surface of the three samples during isothermal sintering. The variation in porosity in the cross section of each sintered sample along sample length was found to be closely related to the nitrogen gas flow field near the sintering surfaces. 展开更多
关键词 aluminum alloy SINTERING pore distribution NITROGEN computational fluid dynamics (CFD) modeling
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Theoretical simulation study of laser-induced plasma bombardment on bacteria
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作者 Junxiao WANG Yan ZHANG +6 位作者 Wanfei ZHANG Yong GUO Lei ZHANG Zefu YE Zhujun ZHU Wangbao YIN Suotang JIA 《Plasma Science and Technology》 SCIE EI CAS 2024年第10期101-107,共7页
With the rapid advancement of laser decontamination technology and growing awareness of microbial hazards,it becomes crucial to employ theoretical model to simulate and evaluate decontamination processes by laser-indu... With the rapid advancement of laser decontamination technology and growing awareness of microbial hazards,it becomes crucial to employ theoretical model to simulate and evaluate decontamination processes by laser-induced plasma.This study employs a two-dimensional axisymmetric fluid dynamics model to simulate the power density of plasma bombardment on bacteria and access its decontamination effects.The model considers the transport processes of vapor plasma and background gas molecules.Based on the destructive impact of high-speed moving particles in the plasma on bacteria,we investigate the bombardment power density under various conditions,including different laser spot sizes,wavelengths,plate's tilt angles,and plate-target spacing.The results reveal that the bombardment power density increases with a decrease in laser spot size and wavelength.For instance,when the plate is parallel to the target surface with a 1 mm spacing,the bombardment power density triples as the laser spot size decreases from 0.8 mm to 0.5 mm and quadruples as the wavelength decreases from 1064 nm to 266 nm.Notably,when the plate is parallel to the target with a relatively close spacing of 0.5 mm,the bombardment power density at 0°inclination increases sevenfold compared to 45°.This simulation study is essential for optimizing optical parameters and designing component layouts in decontamination devices using laser-induced plasma.The reduction of laser spot size,wavelength,plate-target spacing and aligning the plate parallel to the target,collectively contribute to achieving precise and effective decontamination. 展开更多
关键词 laser-induced breakdown spectroscopy fluid dynamics model bacterial decontamination
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A stability condition for turbulence model:From EMMS model to EMMS-based turbulence model 被引量:4
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作者 Lin Zhang Xiaoping Qiu +1 位作者 Limin Wang Jinghai Li 《Particuology》 SCIE EI CAS CSCD 2014年第5期142-154,共13页
The closure problem of turbulence is still a challenging issue in turbulence modeling. In this work, a stability condition is used to close turbulence. Specifically, we regard single-phase flow as a mixture of turbule... The closure problem of turbulence is still a challenging issue in turbulence modeling. In this work, a stability condition is used to close turbulence. Specifically, we regard single-phase flow as a mixture of turbulent and non-turbulent fluids, separating the structure of turbulence. Subsequently, according to the picture of the turbulent eddy cascade, the energy contained in turbulent flow is decomposed into different parts and then quantified. A turbulence stability condition, similar to the principle of the energy-minimization multi-scale (EMMS) model for gas-solid systems, is formulated to close the dynamic constraint equa- tions of turbulence, allowing the inhomogeneous structural parameters of turbulence to be optimized. We name this model as the "EMMS-based turbulence model", and use it to construct the corresponding turbulent viscosity coefficient. To validate the EMMS-based turbulence model, it is used to simulate two classical benchmark problems, lid-driven cavity flow and turbulent flow with forced convection in an empty room, The numerical results show that the EMMS-hased turbulence model improves the accuracy of turbulence modeling due to it considers the principle of compromise in competition between viscosity and inertia. 展开更多
关键词 Stability condition Mathematical modeling Turbulence EMMS Hydrodynamics Computational fluid dynamics
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Modeling and simulation of chemically reacting flows in gas-solid catalytic and non-catalytic processes 被引量:5
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作者 Changning Wu Binhang Yan Yong Jin Yi Cheng 《Particuology》 SCIE EI CAS CSCD 2010年第6期525-530,共6页
This paper gives an overview of the recent development of modeling and simulation of chemically react- ing flows in gas-solid catalytic and non-catalytic processes. General methodology has been focused on the Eulerian... This paper gives an overview of the recent development of modeling and simulation of chemically react- ing flows in gas-solid catalytic and non-catalytic processes. General methodology has been focused on the Eulerian-Lagrangian description of particulate flows, where the particles behave as the catalysts or the reactant materials. For the strong interaction between the transport phenomena (i.e., momentum, heat and mass transfer) and the chemical reactions at the particle scale, a cross-scale modeling approach, i.e., CFD-DEM or CFD-DPM, is established for describing a wide variety of complex reacting flows in multiphase reactors, Representative processes, including fluid catalytic cracking (FCC), catalytic conversion of syngas to methane, and coal pyrolysis to acetylene in thermal plasma, are chosen as case studies to demonstrate the unique advantages of the theoretical scheme based on the integrated particle-scale information with clear physical meanings, This type of modeling approach provides a solid basis for understanding the multiphase reacting flow problems in general. 展开更多
关键词 Gas-solid chemically reacting flow Cross-scale modeling and simulation Eulerian-Lagrangian scheme Computational fluid dynamics (CFD) Discrete element method (DEM) Discrete phase model (DPM)
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