The Comparison with Numerical Simulation Results of Steam-Water Flow Field and Experimental Data for Car Exhaust Pipe

2011 ◽  
Vol 187 ◽  
pp. 570-574
Author(s):  
Qing Guo Liu ◽  
Yan Ma ◽  
Chun Mei Yang

In this paper, the physical model for flow field of exhaust pipe has been established on the condition of a liquid-gas exhaust pipe from cars using ethanol gasoline. The numerical simulation results for internal flow field of car exhaust pipe are compared with the experimental data. It is showed that the outside free vortex tangential velocity and axial velocity of single-phase flow field have been simulated better. It is indicated in the simulation of separation process of steam-water two-phase: The relative error, comparing the relationship between flow and separation efficiency with measured of that is less than 7%, and the same to 15%, comparing the relationship between flow and separation ratio with measured of that. Thereby, it is confirmed correctly for the mathematical model founded for numerical calculation and the algorithm selected.

2019 ◽  
Vol 33 (24) ◽  
pp. 1950279
Author(s):  
Xinhua Song ◽  
Xiaojie Li ◽  
Yang Wang ◽  
Honghao Yan

In this paper, a computational fluid dynamics–discrete element method (CFD–DEM) coupling method is established to simulate the starch granule injection by coupling CFD and DEM. Then a gas–solid two-phase pulsed jet system is designed to capture the flow field trajectory of particle injection (colored starch with a mean diameter of 10.67 [Formula: see text]m), and the image is processed by color moment and histogram. Finally, the simulation results are compared with the experimental results, and the following conclusions are drawn. The numerical simulation results show that with the increase of injection pressure, the injection height increases gradually. When the injection pressure reaches above 0.4 MPa, the increase of injection height decreases. The experimental images show that the larger the pressure (i.e., the greater the initial velocity), the faster the velocity of particle distribution in the space, and the injection heights with the injection pressures of 0.4 MPa and 0.5 MPa are close, which is consistent with the result from the FLUENT numerical simulation based on CFD–DEM.


2005 ◽  
Vol 127 (4) ◽  
pp. 479-486
Author(s):  
Bin Liu ◽  
Mauricio Prado

For any pumping artificial lift system in the petroleum industry, the free gas significantly affects the performance of the pump and the system above the pump. A model, though not a complete two-phase flow model, has been developed for the effective prediction of separation efficiency across a wide range of production conditions. The model presented is divided into two main parts, the single-phase flow-field solution and the bubble-tracking method. The first part of the model solves the single-phase liquid flow field using the computational fluid dynamics approach. Then, a simple bubble-tracking method was applied to estimate the down-hole natural separation efficiency for two-phase flow. A comparison between the results of the model and the experimental data was conducted. It shows a very good agreement with the experimental data for lower gas void fractions (bubble flow regime).


2012 ◽  
Vol 490-495 ◽  
pp. 3786-3791
Author(s):  
Qing Guo Liu ◽  
Yan Ma

The flow field of car exhaust pipe using ethanol gasoline has been researched, the continuity equation of a mixed two-phase model have been established by means of the mathematical model of two-phase flow field, and the simulation for the velocity distribution of droplets radial slipping in exhaust gas have been achieved. By using the divided grid and setting these four boundary conditions as conditions of the entrance, flow conditions at the end of the export, overflow conditions of the export, solid-wall boundary conditions, the iterative steps of calculation process and the relationship among the residuals of various parameters have been obtained. State of exhaust flow have been calculated using algebraic slip model (ASM) ,obtaining the distribution rule of the internal flow field in exhaust pipe for the disconnection of steam-water ,and the characteristics relationship of separation for two-phase flow field of steam-water. The characteristic relationship among flow, split ratio and separation efficiency have been numerically simulated. The existence of the best range of split ratio for a particular exhaust pipe has been confirmed.


2011 ◽  
Vol 130-134 ◽  
pp. 1568-1572
Author(s):  
Hui Wang ◽  
Jie Gang Mu ◽  
Miao Yin Su ◽  
Shui Hua Zheng ◽  
Jin Jing Zhao ◽  
...  

The paper studies the relationship between axial force and breadth of back blade by numerical simulation and experiment. On the basis of the RNG k-ε turbulence model and technology of compact local grids and regional computing, three dimensional numerical simulations to 100HZ165-250 centrifugal pump with various breadths were carried out. Through comparing and analyzing of the flow field, it can be seen that the axial force reduces with the increase of the back blade breadth. After that, the simulation results were verified by the experimental data got from different test devices, and it shows that the conclusions are reliable.


2012 ◽  
Vol 152-154 ◽  
pp. 1303-1306
Author(s):  
Chun Mei Yang ◽  
Yan Ma

The flow field of car exhaust pipe using ethanol gasoline has been researched, the continuity equation of a mixed two-phase model have been established by means of the mathematical model of two-phase flow field, and the simulation for the velocity distribution of droplets radial slipping in exhaust gas have been achieved. By using the divided grid and setting these four boundary conditions as conditions of the entrance, flow conditions at the end of the export, overflow conditions of the export, solid-wall boundary conditions, the iterative steps of calculation process and the relationship among the residuals of various parameters have been obtained. State of exhaust flow have been calculated using algebraic slip model (ASM) ,obtaining the distribution rule of the internal flow field in exhaust pipe for the disconnection of steam-water ,and the characteristics relationship of separation for two-phase flow field of steam-water. The characteristic relationship among flow, split ratio and separation efficiency have been numerically simulated. The existence of the best range of split ratio for a particular exhaust pipe has been confirmed.


2011 ◽  
Vol 52-54 ◽  
pp. 1532-1537
Author(s):  
Shu Zhen Shang ◽  
Gui Min Lu ◽  
Xiao Ling Tang ◽  
Zu Xin Zhao ◽  
Wei Cao

Effects of deformation temperature and strain rate on deformation behavior of semi-solid 6061 alloy were investigated on Gleeble3800 thermal-mechanical simulator. On basis of the experimental data of semi-solid 6061, a model was established to describe the relationship between the processing parameters and flow stress, which showed that the experimental results and calculation ones fitted well. It would be beneficial to realize the distribution of stress and strain during the semi-solid forming on the basis of numerical simulation technology. This research paper presented the numerical simulation results of the 6061 alloy during the backward extrusion thixoforming process.


2012 ◽  
Vol 616-618 ◽  
pp. 655-661 ◽  
Author(s):  
Run Quan Yang ◽  
Huai Fa Wang ◽  
Jian Chao Liu

A laboratory scale jet flotation column system was designed and air inflation for flotation column was provided by jet aerator with a chamber. In order to understand interior flow field distribution of jet aerator and flotation column, two-phase turbulent flow model was established by use of commercial computational fluid dynamics (CFD) software FLUENT 6.3.26. Modeling of the flow field was firstly established with GAMBIT 2.3.16; standard k-ε turbulence model and multiphase flow model MIXTURE were adopted for gas-liquid two-phase numerical simulation about jet aerator and flotation column. The simulation results show that gas-liquid two-phase mixing have been established by the cavity entrainment vortex flow in jet aerator with a chamber, and the distortion was really occurred although the reversed cone feed inlet have been designed, at the same time non-uniform distribution of air-bubble was also simulated. Simulation results can help to optimize the structure of the jet flotation column.


Author(s):  
V. I. Maksimov ◽  
A. Е. Nurpeiis

We suggested a new approach for describing heat transfer in thermosyphons and determining the characteristic temperatures. The processes of thermogravitation convection in the coolant layer at the lower cap, phase transitions in the evaporation zone, heat transfer as a result of conduction in the lower cap are described at the problem statement. The main assumption, which was used during the problem formulation, is that the characteristic times of steam motion through the thermosyphon channel are much less than the characteristic times of thermal conductivity and free convection in the coolant layer at the lower cap of the thermosyphon. For this reason, the processes of steam motion in the thermosyphon channel, the condensate film on the upper cap and the vertical walls were not considered. The problem solution domain is a thermosyphon through which heat is removed from the energy-saturated equipment. The ranges of heat flow changes were chosen based on experimental data. The geometric parameters of thermosyphon and the fill factors were chosen the same as in the experiments (height is 161 mm, diameter is 42 mm, wall thickness is 1.5 mm, ε=4-16%) for subsequent comparison of numerical simulation results and experimental data. In the numerical analysis it was assumed that the thermophysical properties of thermosyphon and coolant caps do not depend on temperature; laminar flow regime was considered. The dimensionless equations of vortex, Poisson and energy transfer for the liquid coolant under natural convection and the equations of thermal conductivity for the lower cap wall are solved by the method of finite differences. Numerical simulation results showed the relationship between the characteristic temperatures and the heat flow supplied to the bottom cap of thermosyphon. The results of the theoretical analysis are in satisfactory agreement with the known experimental data. 


Author(s):  
Bin Liu ◽  
Mauricio Prado

For any pumping artificial lift system in petroleum industry, the free gas significantly affects the performance of the pump and the system above the pump. A model, though not a complete two-phase flow model, has been developed for the effective prediction of separation efficiency across a wide range of production conditions. The model presented is divided into two main parts, the single-phase flow field solution and the bubble tracking method. The first part of the model solves the single-phase liquid flow field using the CFD approach. Then, a simple bubble-tracking method was applied to estimate the down-hole natural separation efficiency for two-phase flow. A comparison between the results of the model and the experimental data was conducted. It shows a very good agreement with the experimental data for lower gas void fractions (bubble flow regime).


2012 ◽  
Vol 184-185 ◽  
pp. 341-347
Author(s):  
Cai Jin Wu ◽  
Zheng Fei Ma ◽  
Yong Yang

The three-dimension flow field and the separation efficiency of the inclined cut-in double-inlet cyclone were simulated numerically with Reynolds Stress Model (RSM). Numerical results show that the flow field nonsymmetry is improved in the inclined cut-in double-inlet cyclone and the swirl in the flow field was decreased greatly compared to that in the single-inlet cyclone. With the increase of inclined angle, both the tangential velocity and the axial velocity first increase and then decrease, reaching a peak at inclined 12 ° angle and at inclined 10 ° angle, respectively. The pressure drop in the inclined cut-in double-inlet cyclone increases first and then decreases with the increase of inclined angle, reaching a maximum far lower than that in the single-inlet cyclone, while the change of the radial velocity is not obvious. The separation efficiency of the inclined cut-in double-inlet cyclone could be effectively improved and the optimum inclined angle is 10 °.


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