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Study of the Wall Slip Effect on Viscous Fluid Micro-extrusion Process Congping Chena, Xiaoyun Wangb, Jieguang Huang College of Mechanical and Power Engineering, China Three Gorges University, Yichang, 443002, China aemail:mechencp@163.com, bemail:acuando@sohu.com Keywords: Wall Slip; CFD; Flow Rate; Fluid Expansibility Abstract.
In this research, a wall slip model based on a micro-tube flow was developed, and then the wall slip effect on the viscous fluid micro-extrusion process was explored by computational fluid dynamics (CFD) with different extruding pressures.
Under different inlet pressures, a series of simulations by CFD were used to comparatively study the fluid extrusion expansibility, velocity, flow rate on the condition with and without wall slip, the results showed that wall slip make the fluid resistance and expansibility decrease, and the fluid mass flow rate increase. 2 Wall Slip Model Generally, the micro-extrusion process is on the condition of low velocity, viscosity and wall resistance.
In micro-scale flow, the Navier slip model is always employed and given as (1) Here, is the shear stress of fluid in the wall, is the slip coefficient, is the tangential velocity of the wall, is the tangential velocity of fluid in the wall, is the material parameter. 3 Numerical Simulations 3.1 CFD Model In order to study the fluid extrusion expansibility, it is required to track out the outline of the fluid/liquid extruded out, however, the outline is changed with extrusion procedure, which is very difficult to develop a theory model.
Simulation model’s dimensions [mm] Parameter Micro-tube Air Chamber Diameter Length Wall thickness Diameter Length Value 0.5 15 0.75 2 5 Set the tube inlet pressures as 5MPa, 6MPa, 7MPa, 8MPa and 9MPa, respectively, the gas-liquid component ratio figures are shown in Fig. 2 and Fig. 3.It can be noticed that, when the fluid is extruded out to the air, its section width is larger than that of the micro-tube.

Study on energy saving model of air condition for subway station ZHANG Lin-xin1,a, LI Gui-qin2,b, Mitrouchev Peter3,c,GUO Lei4,d 1,2,4Shanghai Key Laboratory of IntelligentManufacturing and Robotics, Shanghai University, Shanghai 200072, China 3University Grenoble Alpes, G-SCOP, F-38000, Grenoble, France azlxin163@163.com,bleeching@staff.shu.edu.cn,cpeter.mitrouchev@g-scop.inpg.fr, d422414261@qq.com Key words: numerical simulation; orthogonal experimental method; multiple linear regression; energy saving strategies Abstract:In order to analyze air conditioner energy conservation of subway station quantitatively,three-dimensional numerical simulations study is conductedby using CFD theory for air distribution of subway platform,and the flow field and temperature field of the platform under different environment conditions are obtained.The orthogonal experiment method is applied to the numerical simulation analysis for human comfort under different parameters.
Theresearch of three-dimensional numerical simulation on the airflow organization of the platform based on CFD theory is conducted in this paper.The orthogonal experiment method is chosen to select portion of the data for test,greatly reducing the test time; The function relationship between human comfort and the boundary conditions ofthe platformis foundby the use of multiple linear regression fitting method, and the results are compared with the actual detection, providing a theoretical basis for the energy saving strategyproposed.
The test results and the simulation results are in good agreement, indicating that the CFD simulation can accurately reflect the actual situation, has a good applicability.
Test times TemperatureK） Velocity（m/s） Test times (a)temperaturecomparison (b)velocitycomparison Fig.4 Comparison between measurement results and simulation results Conclusion (1)The simulation results show that the temperature distribution is relatively uniform, wind speed is higher on the inlet area, with an obvious wind feeling, other areas have lower wind speed; (2)The field test shows that, the error between the calculation results of actual tests and simulation results is less than 5%,the CFD model can accurately reflect the actual situation, has a good applicability.
(Natural Science Edition),2009:8 [5] Wang Jianyu,RenQingchang.Model Predictive Control and Case Simulation for VAV System[J].Journal of System Simulation,2008,20(16)

Thermal Management of Electronic Components by Using Computational Fluid Dynamic (CFD) Software, FLUENTTM in Several Material Applications (Epoxy, Composite Material & Nano-silver) M.
The strength of CFD software in handling heat transfer problems is proved to be excellent.
In the simulation model, the arrangement of the packages begins with the PLCC 1 located in front of motherboard followed by 2, 3 and 4.
Seetharamu, Application of CFD in Cooling Electronic Packages, The Seventh Asian Congress of Fluid Mechanics, pp 777-780, December 1997
Kuat, CFD application in Electronics System Cooling, Final Year Project, School of Mechanical Engineering, Universiti Sains Malaysia, 1998

Dynamic filtration with rotating disks is modeled by three-dimensional graphics software and its flow field is analyzed and numerical simulated by CFD software.
Simulation results are consistent to the practice, which provides important theoretical basis for improving and optimization of dynamic filtration with rotating disks.
By the using of CFD software, the geometric model of dynamic filtration with rotating disks is meshed.
By the using of CFD software parametric solver flexibly, the flow field velocity distribution of dynamic filtration with rotating disks for w=0.25, w=2, and w=4rad/s are obtained.
[2]Xu Zhou, He Gao-hong, Luhui Ding, CFD Simulation of Dynamic Filtration System with Rotating Disk, Dalian university of technology，Master thesis，2009

Yuan et al.[2-4] presented an investigation of the unsteady pressure pulsation caused by cavitation, RSI in the pump by CFD simulation and particle image velocimetry measurement method.
The CFD study runs at the same conditions as the experiment.
Unsteady turbulent simulation and pressure fluctuation analysis for centrifugal pumps.
Numerical Simulation of Pressure Fluctuation and Radial Force in a Double Volute Pump.
Wu, et al. 3D Unsteady Turbulence Simulation of the Runaway Transients of the Francis Turbine.

Project natural ventilation simulation (CFD study) Natural ventilation is a passive cooling strategy that uses natural air currents to cool buildings.
CFD simulations can be used to predict the airflow patterns, temperature distribution, and ventilation rates in a building.
Run the CFD simulation.
The CFD simulation will solve the equations of fluid flow and heat transfer. 4.
The results of the CFD simulation is used to assess the performance of the natural ventilation system.

CFD Simulation Simulations (CFD) allow the solution of the equations governing the physical behavior of a fluid.
The device will be fabricated and installed to verify the results of both the hydraulic design and CFD simulation reported in this paper.
CFD Numerical simulations of Francis turbines | Simulación numérica (CFD) de turbinas Francis.
CFD Numerical simulation of the flow in hydraulic turbo machines, state of art and source of mistake.
Application of Richardson extrapolation method to the CFD simulation of vertical-axis wind turbines and analysis of the flow field.

Table 4 Equations of Two-dimensional CFD model [20].
Table 5 Summarized of Membrane Reactor Modeling and Simulation Studies.
CFD Computational fluid dynamics Pd palladium MR Membrane reactor SCR Steam to carbon ratio References [1] S.
Bian et al., "CFD simulation of a hydrogen-permeable membrane reactor for CO2 reforming of CH4: the interplay of the reaction and hydrogen permeation," Energy & Fuels, vol. 34, no. 10, pp. 12366-12378, 2020
Lim, "CFD simulation of methane steam reforming in a membrane reactor: Performance characteristics over range of operating window," International Journal of Hydrogen Energy, vol. 46, no. 59, pp. 30402-30411, 2021

Based on CFD software, three dimensional unsteady internal flow field numerical simulation of some type rotor oil pump is carried out.
And, the velocity and pressure simulation results at different speeds are obtained.
Based on acoustic finite element and infinite element method, CFD software and acoustic solver software are used to simulate the flow induced noise of rotor oil pump.
In this paper, by using the professional CFD software and the acoustic software, the internal flow induced noise of rotor oil pump is studied.
Fig.3 Flow characteristic curve at different speeds 2.2 Sound field simulation of oil pump 2.2.1 The simulation flow of sound field Based on the result of numerical simulation in internal flow field of the oil pump, couple the main variables such as pressure and flow velocity obtained from simulation results with acoustic solver.

CFD packages used in this study, with powerful computing features, it's built-in the dynamic fluid dynamics equations, have to know how to self do rational, logical judgments engineering objects.
Experimental equipment In order to identify the most appropriate air flow field inside the dust collector pressure situation, the research laboratory equipment commercial computational fluid dynamics CFD (computational fluid dynamic CFD) commercial software package, selected under different conditions,conducted simulation experiments,and want to pursue the purpose of this study, the dust collector internal air flow field flow pressure in what circumstances?
The present simulation experiment using the same air inlet a suction wind speed of 3.0m / s, and to cause the entire virtual dust collecting apparatus (Figure 1), its internal air flow simulation, in the Z axis direction was provided with a downward gravity acceleration of -9.8 (m / s ²).
The simulation of air were the type of gas should be regarded as a non-Newtonian fluid not sticky (Inviscid) .
Numerical Simulation In recent decades, CFD has been greatly developed, all phenomena involving fluid flow, heat exchange and molecular transport problems, almost all through computational fluid dynamics methods to the analysis and simulation [6].