scholarly journals Analysis of Bubble Flow Mechanism and Characteristics in Gas–Liquid Cyclone Separator

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 123
Author(s):  
Yujie Bai ◽  
Hong Ji ◽  
Yaozhuo Liu ◽  
Lei Li ◽  
Shengqing Yang
Keyword(s):  
Gas Discharge ◽  
Separation Mechanism ◽  
Bubble Flow ◽  
Flow Mechanism ◽  
Exhaust Port ◽  
Flow Effect ◽  
Calculation Results ◽  
Flow Field Characteristics ◽  
Discharge Efficiency ◽  
Better Than

The separation of bubbles in a gas–liquid cyclone is complicated. A combination of numerical simulation and visual experimentation was considered apt to reveal the microscopic mechanisms of bubble flow. First of all, cyclones with different structures were numerically simulated. The calculation results show that the larger the diameter of the exhaust port, the better the bubble flow effect. When the exhaust port diameter was 24 mm, the gas discharge efficiency was 8% higher than that with an exhaust port diameter of 16 mm. The sequence of the bubble flow effect of a four-structure cyclone was obtained, and the gas discharge efficiency of the cyclone with a rectangular inlet was 7% higher than that of the trapezoidal inlet. Finally, a visual experimental platform was built to compare the rectangular inlet cyclone and spiral inlet cyclone with the best bubble flow effect. In accordance with the simulation numerical calculations, the bubble flow effect of the rectangular inlet cyclone was better than that of the spiral and trapezoid inlet cyclones, and the rectangular inlet in the middle was better. This article provides a specific theory and experience to guide further research on the separation mechanism, flow field characteristics and structurally optimal design of gas–liquid cyclones.

scholarly journals Study of the Effect of Centrifugal Force on Rotor Blade Icing Process

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Zhengzhi Wang ◽  
Chunling Zhu
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Force ◽  
Rotor Blade ◽  
Flow Direction ◽  
Three Dimensional ◽  
Simulation Method ◽  
Two Phase ◽  
Numerical Simulation Method ◽  
Calculation Results ◽  
Flow Field Characteristics

In view of the rotor icing problems, the influence of centrifugal force on rotor blade icing is investigated. A numerical simulation method of three-dimensional rotor blade icing is presented. Body-fitted grids around the rotor blade are generated using overlapping grid technology and rotor flow field characteristics are obtained by solving N-S equations. According to Eulerian two-phase flow, the droplet trajectories are calculated and droplet impingement characteristics are obtained. The mass and energy conservation equations of ice accretion model are established and a new calculation method of runback water mass based on shear stress and centrifugal force is proposed to simulate water flow and ice shape. The calculation results are compared with available experimental results in order to verify the correctness of the numerical simulation method. The influence of centrifugal force on rotor icing is calculated. The results show that the flow direction and distribution of liquid water on rotor surfaces change under the action of centrifugal force, which lead to the increasing of icing at the stagnation point and the decreasing of icing on both frozen limitations.

Discussion on Burden Calculation of Ferromanganese Alloy Production

2011 ◽  
Vol 194-196 ◽  
pp. 248-254
Author(s):  
Shao Jun Chu ◽  
Pei Xiao Liu ◽  
Pei Xian Chen
Keyword(s):  
Error Rate ◽  
Total Error ◽  
Reference Value ◽  
Mass Conservation ◽  
Recovery Method ◽  
Total Error Rate ◽  
Calculation Results ◽  
Improve Production Technology ◽  
Technology Product ◽  
Better Than

The burden calculation of ferromanganese alloy was calculated based on the slag composition and designed product. The calculation results showed the total error rate of this method was 1.53% and the error rate of ore, coke and silicon was 4.66%, 1.71%, and 5.66% respectively, which was much better than using the traditional elements recovery method with the total error rate was 8.00% and the silicon error rate reached to 18.55%. This new method is more accurate than the traditional method and much closer to the actual production data. And it can apply to different ferroalloy factories because it is based on phase diagram and the mass conservation law. At the same time, the calculation result can reflect the gap between enterprise production craft level and ideal production level. This method has certain reference value to improve production technology, product quality and economic profit of enterprise.

Numerical Simulation of Turbulent Mixing for Dislocated Blades in a Stirred Tank

2011 ◽  
Vol 354-355 ◽  
pp. 559-563
Author(s):  
Lei Shi ◽  
Shen Jie Zhou ◽  
Feng Ling Yang ◽  
Fan Jin Hu
Keyword(s):  
Numerical Simulation ◽  
Turbulent Mixing ◽  
Stirred Tank ◽  
Industrial Processes ◽  
Mixing Efficiency ◽  
Mixing Process ◽  
Flow Number ◽  
Stirred Tanks ◽  
Calculation Results ◽  
Better Than

Mixing efficiency is an important parameter in the design of many industrial processes in stirred tanks. In this study, CFD technology was used to simulate the mixing process inside the stirred tank with dislocated blades and standard turbine. Calculations were performed to study the effects of agitator speed and the configuration of impellers on mixing efficiency. The results showed that the flow field in the stirred tank with the dislocated blades is better than the standard turbine, and the flow number of the dislocated blades had been improved while the power number had been reduced. According to calculation results of Wr, we found the mixing efficiency of the dislocated blades had been improved about 4 times than that of standard turbine.

scholarly journals Research on Rubber Spring Model of High-speed EMU Based on Non-hyperelastic Forces

Mechanika ◽  
2021 ◽  
Vol 27 (1) ◽  
pp. 12-21
Author(s):  
Chuanbo XU ◽  
Maoru CHI ◽  
Liangcheng DAI ◽  
Yiping JIANG ◽  
Yongfa CHEN ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Prediction Accuracy ◽  
High Speed ◽  
Dynamic Condition ◽  
Static Condition ◽  
Good Prediction ◽  
Calculation Formula ◽  
Good Prediction Accuracy ◽  
Calculation Results ◽  
Better Than

The research on the mechanical model of rubber spring is one of the hot spots in train dynamics. In order to accurately calculate the viscoelastic force of the rubber spring, especially the non-hyperelastic forces (NHEF) part, a NHEF model is proposed based on the elliptic approximation method. Furthermore, the calculation formula of periodic energy consumption is put forward. The NHEF model is verified by experiments, and the function λ isconstructed to verify the formula of periodic energy consumption. The calculation results showed that the NHEF model had high accuracy in predicting the dynamic and quasi-static NHEF of rubber spring, the prediction accuracy of shear condition was better than that of compression condition, and the accuracy of quasi-static condition was better than that of dynamic condition; the calculation formula of periodic energy consumption had a good prediction accuracy in all working conditions.

Parameter Analysis of the Static Droplets Phase Transformation Under the Pressure Variation Condition

2016 ◽  
Author(s):  
Fulong Zhao ◽  
Qianfeng Liu ◽  
Hanliang Bo
Keyword(s):  
Phase Transformation ◽  
Steam Generator ◽  
Pressure Variation ◽  
Parameter Analysis ◽  
Separation Mechanism ◽  
Time Step ◽  
Water Separation ◽  
Ultimate Pressure ◽  
Water Separator ◽  
Calculation Results

The steam-water separator is a vital important plant in the steam generator, whose function is to remove transported small droplets in the vapor stream and provide the high quality saturated steam for the steam turbine. The performance of the steam-water separator in the steam generator has a great impact on the safety and economy of the nuclear power station. The steam-water separation mechanism is far from maturity as a result of the complexity of the separator structure and the interaction of the steam, droplets together with the liquid film. Our research team tries to build a new research route about the steam-water separation mechanism from the microcosmic behavior aspects of the droplets including the production, movement, collision, extinction as well as the phase transformation. When the droplets move during the steam-water separator, the pressure could decrease continuously due to the resistance and the structure variation, which may break the liquid-vapor equilibrium and make the droplets evaporate and then could greatly influence the steam-water separating characteristics. This paper builds a hydrodynamic-kinetic model on the static droplets phase transformation under the pressure variation condition based on the physics phenomenon description of the droplets evaporation as well as the mechanism explanation. Through different kinds of calculations by change of the time step, the model has been proved to be independent on the time step. In order to make sure that the new model is correct, this paper compares the calculation results with the experimental ones and finds that the calculation results are in wonderful accordance with the existing experimental data. The relative errors between the calculation results and the experimental ones are between ± 5%. At last, this paper conducts the detailed sensitivity analysis of different relative parameters, which are useful for the understanding of the process of the droplets evaporation as well as could deepen the comprehension of the droplets phase transformation mechanism under the condition of the pressure change. The calculation results show that the evaporation characteristics of the static droplets under the pressure variation condition are predominantly influenced by the initial pressure, the ultimate pressure of the environment, as well as the difference of the initial and ultimate pressure. In addition, the initial radius of the droplets and the environment temperature can have a great impact on the droplets evaporation characteristics This model could provide the theoretical reference for further study of the process of the droplets phase transformation during transport in the steam-water separator as well as the steam-water separating performance of the separator, which can guide the design of the steam-water separation plants.

Assessment of Scavenge Efficiency for a Helicopter Particle Separation System

2012 ◽  
Vol 57 (2) ◽  
pp. 41-48 ◽  
Author(s):  
L.Y. Jiang ◽  
M. Benner ◽  
J. Bird
Keyword(s):  
Shape Factor ◽  
Particle Separation ◽  
Operating Conditions ◽  
Separation Mechanism ◽  
Separation System ◽  
Small Particles ◽  
Inlet Velocity ◽  
Separation Systems ◽  
Large Particles ◽  
Flow Field Characteristics

The effectiveness of a helicopter particle separation system has been numerically assessed at practical operating conditions and sand environments for various scenarios. The particle separation mechanism and its limitations are revealed by the predicted flow field characteristics and particle trajectories. The separation-by-inertia concept is effective for removing large particles, but problematic for small particles of diameter ≤36 μm for the configuration and operating conditions considered in the present study. It is also found that particle size, shape factor, and rebound characteristics exert substantial effects on particle scavenge efficiency. However, the effects of gravity, particle inlet velocity, inlet mass distribution, and engine-operating conditions on scavenge efficiency are minor or limited. Finally, a few suggestions for further investigation on engine particle separation systems are included.

Simulation of Liquid/Solid Interfacial Structures in Metal/Ceramics Wetting Systems

2006 ◽  
Vol 11-12 ◽  
pp. 485-488 ◽  
Author(s):  
Takehiko Makino ◽  
Shun Ichiro Tanaka
Keyword(s):  
Contact Angles ◽  
First Principles Calculation ◽  
Interatomic Potentials ◽  
Forming Process ◽  
Interfacial Structures ◽  
Atomic Interactions ◽  
Calculation Results ◽  
Wetting Behaviors ◽  
The Relationship ◽  
Better Than

Wetting can be regarded as a kind of effective nanostructure-forming process. To control the structure, a study on the relationship between atomic interactions and the resultant wetting behaviors is required. To model the wetting system, two sets of interatomic potentials for Metal/MgO(100) systems are derived from first principles calculation results for the simple configurations. A molecular dynamics method is applied to simulate the system and shows that Al atoms wet better than Sn atoms on the MgO substrate. The tendency is consistent with the experimental contact angles. The interfacial structures are different between these two systems.

scholarly journals FEASIBILITY VERIFICATION OF VIRTUAL REFERENCE STATION TECHNOLOGY IN GEOLOGICAL HAZARD MONITORING

2021 ◽  
Vol XLIII-B1-2021 ◽  
pp. 235-240
Author(s):  
Q. Zhang ◽  
M. Chen ◽  
J. Wu ◽  
C. Xu ◽  
F. Wang
Keyword(s):  
Real Time ◽  
Early Warning ◽  
Reference Station ◽  
Geological Hazard ◽  
Virtual Reference ◽  
Geological Disaster ◽  
Calculation Results ◽  
Disaster Monitoring ◽  
Monitoring And Early Warning ◽  
Better Than

Abstract. The surveying and mapping administrative competent departments in 31 provinces (autonomous regions and municipalities) have built provincial-level satellite navigation and positioning reference stations and data centers, and provided CORS services. This provides a good condition for exploring the application of geological hazard monitoring and early warning using Virtual Reference Station (VRS) service based on CORS. At present, the layout mode of "one point one reference station" is usually adopted, when GNSS is used for geological disaster monitoring and early warning. However, the high deployment cost of this plan limits its largescale promotion and application. Using the existing CORS service resources of natural resource system, this paper carried out the application experiment of virtual reference station in geological hazard monitoring application at Huanglongya geological hazard monitoring site in Shaanxi Province, and assessed the virtual reference station data quality, comparative analyzed the precision of static baseline processing results and GNSS real-time deformation monitoring results. The experimental results show that the overall quality of virtual reference station data is better than that of the monitoring station, and the accuracy of the static baseline calculation results is better than 1.0cm in the X direction, and better than 2.0cm in the Y direction and Z direction, which is similar to the static baseline calculation results formed by the physical reference station. The accuracy of the baseline results of real-time observation data calculation is better than 5mm in horizontal RMS and 15mm in vertical RMS. Therefore, it can be seen that the virtual reference station is feasible to be used as the reference station for geological disaster monitoring. In addition, the application experiment of network RTK real-time dynamic single epoch positioning mode is also carried out in geological hazard monitoring. The experimental results show that the RMS values of all three directions are ±3.7mm, ±9.2mm and ±5.0mm respectively, which meet the precision requirements of GNSS disaster monitoring. Therefore, it is also a feasible scheme for geological disaster monitoring and early warning.

scholarly journals USE OF 3D-VISUALIZATION MEDIA IN NUCLEOPHILIC SUBSTITUTION REACTION MATERIAL TO IMPROVE STUDENTS' CONCEPT MASTERY

2020 ◽  
Vol 5 (2) ◽  
pp. 213-219
Author(s):  
Dessi Nur Adiska ◽  
Liliasari Liliasari ◽  
Iqbal Musthapa
Keyword(s):  
Nucleophilic Substitution ◽  
Substitution Reaction ◽  
3D Visualization ◽  
Nucleophilic Substitution Reaction ◽  
Multiple Choice Questions ◽  
Concept Mastery ◽  
Post Test ◽  
Calculation Results ◽  
Technological Developments ◽  
Better Than

Development of technology is increasingly rapid today, including in the field of education. Technological developments are sometimes not used properly in the learning process, so that students not actively studying in class. The purpose of this study was to determine the effect of using 3D visualization media on nucleophilic substitution reaction material to improve students' concept mastery. Research method used was a quasi-experiment with pre-test and post-test design, involved 68 students from two different universities in West Java. The test instrument to measure concept mastery consisted of nine reasoned multiple-choice questions. The results showed that the use of 3D visualization media in nucleophilic substitution reaction materials can improve students' mastery of concepts. Based on the N-gain calculation results, University A was better than University B except for the indicators of determining that obtained a medium category and sorting that obtained a low category. There were four indicators of concept mastery used, including determining, analyzing, linking, and sorting indicators.

scholarly journals Investigation on Bubble Diameter Distribution in Upward Flow by the Two-Fluid and Multi-Fluid Models

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5776
Author(s):  
Yongzhong Zeng ◽  
Weilin Xu
Keyword(s):  
Experimental Data ◽  
Volume Fraction ◽  
Fluid Model ◽  
Bubble Diameter ◽  
Diameter Distribution ◽  
Bubble Flow ◽  
Calculation Results ◽  
Two Fluid Model ◽  
Gas Volume ◽  
Two Fluid

Bubble flow can be simulated by the two-fluid model and the multi-fluid model based on the Eulerian method. In this paper, the gas phase was further divided into several groups of dispersed phases according to the diameter by using the Eulerian-Eulerian (E-E) multi-fluid model. The diameters of bubbles in each group were considered to be the same, and their distributions were reorganized according to a specific probability density function. The experimental data of two kinds of bubble flow with different characteristics were used to verify the model. With the help of the open-source CFD software, OpenFOAM-7.x (OpenFOAM-7.0, produced by OpenFOAM foundation, Reading, England), the influences of the group number, the probability distribution function, and the parameters of different bubble diameters on the calculation results were studied. Meanwhile, the numerical simulation results were compared with the two-fluid model and the experimental data. The results show that for the bubble flow with the unimodal distribution, both the multi-fluid model and the two-fluid model can obtain the distribution of gas volume fraction along the pipe radius. The calculation results of the multi-fluid model agree with the experimental data, while those of the two-fluid model differ greatly from the experimental data, which verifies the advantage of the multi-fluid model in calculating the distribution of gas volume fraction in the polydisperse bubble flow. Meanwhile, the multi-fluid model can be used to accurately predict the distribution of the parameters of each phase of the bubble flow if the reasonable bubble diameter distribution is provided and the appropriate interphase force calculation model is determined.

Sign in / Sign up

Export Citation Format

Share Document