scholarly journals Vibroacoustic characteristics analysis of a planetary gear reducer considering the exterior housing structure

2021 ◽  
Vol 12 (1) ◽  
pp. 539-557
Author(s):  
Lihong Jin ◽  
Junpeng Shao ◽  
Xigui Wang ◽  
Yongmei Wang ◽  
Baixue Fu
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Dynamic Characteristics ◽  
Optimization Design ◽  
Structural Parameters ◽  
Planetary Gear ◽  
Design Parameters ◽  
Weak Links ◽  
Acoustic Characteristics ◽  
Transfer Path

Abstract. Previous studies have attempted to identify weak links in the dynamic characteristics of the planetary gear reducer (PGR) exterior body structure (EBS). Through numerical simulation, these studies analyzed the mode and natural frequencies and the vibration types of each order of the EBS. However, these scholars have never focused on the main factors affecting the dynamic characteristics of the EBS of this subject. This study in the topic has analyzed the vibroacoustic characteristics of an EBS and optimized its design using numerical simulation. Herein, the contribution of the vibration transfer path from the excitation points on the exterior body to the machine foot is emphatically revealed, and the influences of the main structural parameters on the transfer characteristics are discussed. An optimal EBS for a PGR with lower acoustic vibrations is designed in detail, and a composite EBS with damping vibration attenuation and acoustic absorption is proposed. The radiation acoustic characteristics without acoustic protection and damping materials are analyzed. These research results are implemented in order to realize the dynamic characteristics, transmission, and radiation acoustic characteristics as objects of optimization, and the structural design parameters of the PGR exterior body are deeply optimized using dynamic modification and sensitivity analysis. This topic focuses on the vibroacoustic coupling of EBS in stationary fluid and average flow field. Based on the analysis method of theoretical modeling and numerical calculation, the EBS dynamic response and vibroacoustic characteristics under the action of frontal excitation external acoustic flow field are studied, which will be beneficial to explore the comprehensive optimization design of PGR dynamic and vibroacoustic properties.

scholarly journals Influence of Vortex Finder Structure on Separation Performance of Double-Overflow Three-Product Hydrocyclones

Separations ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 79
Author(s):  
Yuekan Zhang ◽  
Jiangbo Ge ◽  
Lanyue Jiang ◽  
Hui Wang ◽  
Junru Yang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Experimental Research ◽  
Separation Efficiency ◽  
Structural Parameters ◽  
Separation Performance ◽  
Insertion Depth ◽  
Flow Field Characteristics ◽  
Vortex Finder ◽  
Fine Classification

In view of the difficulty of traditional hydrocyclones to meet the requirements of fine classification, a double-overflow three-product (internal overflow, external overflow and underflow) hydrocyclone was designed in this study. Numerical simulation and experimental research methods were used to investigate the effects of double-overflow flow field characteristics and structural parameters (i.e., internal vortex finder diameter and insertion depth) on separation performance. The research results showed that the larger the diameter of the internal vortex finder, the greater the overflow yield and the larger the cut size. The finest internal overflow product can be obtained when the internal vortex finder is 30 mm longer than the external vortex finder. The separation efficiency is highest when the internal vortex finder is 30 mm shorter than the external vortex finder.

scholarly journals Experimental Research and Numerical Simulation of Ejector Precipitator in a Fully Mechanized Mining Face

2020 ◽  
Vol 45 (11) ◽  
pp. 9815-9833
Author(s):  
Guodong Zhai ◽  
Wentao Zhang ◽  
Yaozong Li ◽  
Xinghao Lu ◽  
Wenyuan Hu
Keyword(s):  
Numerical Simulation ◽  
Flow Field ◽  
Negative Pressure ◽  
Coal Dust ◽  
Structural Parameters ◽  
Dust Concentration ◽  
Dust Removal ◽  
Measuring Point ◽  
Mining Face ◽  
Supply Water

AbstractIn order to effectively reduce the coal dust concentration in a fully mechanized mining face, this research used laboratory experiment, numerical simulation, and field test to conduct an in-depth exploration of the ejector precipitator installed at the low-level caving coal hydraulic support. Firstly, through the experimental platform in the laboratory, the dust removal effect of the nozzle with different structural parameters was tested, and the 3D particle dynamic analyzer was adopted to verify its atomization characteristics; then, the structural parameters corresponding to the nozzle in the best test results were obtained. Secondly, by using Fluent, the negative pressure flow field in the ejector barrel was numerically simulated. The results indicated that when the pressure of supply water was 12 MPa, the negative pressure value formed in the flow field was the lowest and the inspiratory velocity was the largest, which was conducive to dust removal. Finally, the tests of liquid–gas ratio and dust removal ratio were carried out in a fully mechanized mining face. The results showed that when the nozzle specification recommended by the experiment and the pressure of supply water recommended by the numerical simulation were used, the removal ratios of the total coal dust and the respirable coal dust were 89.5% and 91.0%, respectively, at the measuring point of the highest coal dust concentration. It indicates that the ejector precipitator has a good application effect in reducing the coal dust concentration in a fully mechanized mining face and improving the work environment of coal mine workers.

Optimization Design of Agricultural Fans Based on Skewed-Swept Blade Technology

2019 ◽  
Vol 35 (2) ◽  
pp. 249-258
Author(s):  
Tao Ding ◽  
Lumeng Fang ◽  
Ji-Qin Ni ◽  
Zhengxiang Shi ◽  
Baoming Li ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Energy Efficiency ◽  
Optimization Design ◽  
Control Parameter ◽  
Rapid Development ◽  
Performance Testing ◽  
Design Parameters ◽  
Leakage Flow ◽  
Blade Design ◽  
Direction Control

Abstract.With the rapid development of modern agriculture facilities, agricultural fans have been widely used due to their low pressure and large airflow characteristics. However, existing agricultural fans have large flow losses and low energy efficiencies. To increase the airflow and energy efficiency of these fans, optimization designs based on skewed and swept blades were carried out. First, a “DDZ” agricultural fan (a leaf model agricultural fan commonly used in China) was chosen as the archetype fan. Its performance curves and flow field distribution were obtained by performance testing and numerical simulation. Second, the stack lines of the skewed blade and swept blade were designed based on the original blade, 3 skewed blade parameters (skewed angle a, x direction control parameter kx, and y direction control parameter ky), and 3 swept blade design parameters (swept angle ß, z direction control parameter kz, and r direction control parameter kr). Finally, the optimal skewed blade design parameters (a = 16.8°, kx = 1.65, and ky = 0.5) and optimal swept blade design parameters (ß = 10.6°, kz = -0.33, and kr =0.6) were obtained using numerical simulations and orthogonal testing, which is a response surface method. The numerical simulation results showed that the airflow and energy efficiency ratios of the optimal skewed blade fan were increased by 4.3% and 20.5%, and those of the optimal swept blade fan were increased by 4.5% and 15.4%, respectively, in comparison with those of the original fan. The flow fields showed that the optimal skewed blade mainly reduced the radial flow at the blade root and the leakage flow. The optimal swept blade mainly reduced the leakage flow by changing the distribution of the static pressure on the blade surfaces. Keywords: Agricultural fan, Skewed-Swept blade, Numerical simulation, Optimization.

Application of the Flow Simulation for the Optimization Analysis of SCR DeNOx System of Coal Power Plant

2012 ◽  
Vol 610-613 ◽  
pp. 1533-1539 ◽  
Author(s):  
Xing Lian Ye ◽  
Ding Yang
Keyword(s):  
Numerical Simulation ◽  
Power Plant ◽  
Flow Field ◽  
Physical Model ◽  
Model Experiment ◽  
Optimization Design ◽  
Coal Power Plant ◽  
Physical Model Experiment ◽  
Coal Power ◽  
Scr System

Based on the Selective Catalystic Reduction (SCR) DeNOx project for 2×330MW-unit in a coal power plant, the gas flow field in SCR system has been optimized by numerical simulation. The optimized simulation results were compared with the physical model experiment, and the fly ash sedimentation in the duct was also investigated. Correlation analysis of the results shows that, the flow field predicted by numerical simulation matches very well with that of physical model experiment. Numerical simulation can not only predict but also improve the flow field in SCR system. The combination of simulation and physical model experiment provides a reliable basis for flow field optimization design in SCR system.

Analyzing of Dynamic Characteristics of Special CNC Machine Tool

2010 ◽  
Vol 29-32 ◽  
pp. 2037-2041
Author(s):  
Ke Wang ◽  
Guang Lv ◽  
Xing Wei Sun
Keyword(s):  
Machine Tool ◽  
Dynamic Characteristics ◽  
Optimization Design ◽  
High Efficiency ◽  
Structural Parameters ◽  
Force Frequency ◽  
Cutting Method ◽  
Finite Element Software ◽  
Exciting Frequency ◽  
Motion Parameters

The dynamic characteristics of machine tool is an important factor, which make affect on the cutting stability of machine tool. The poor dynamic characteristics will seriously affect the stability of cutting, make the low cutting efficiency and low machining precision, and also accelerate the wear of tools and even reduce the machine’s service life. So it is necessary to analyze the dynamic characteristics of machine tool, and according to the results of analysis to optimize structural parameters and motion parameters of the machine tools. This paper analyses the dynamic characteristics of machine bed and machined work piece of the CNC special machine tool for Kelly with the finite element software, and analysis of excitation characteristics of cutting tool. It also makes optimization design to the machine bed, through the analysis and optimization, the natural frequency and stiffness will be obviously improved. According to the structure and calculation of the motion parameters we can get the exciting force frequency to workpiece when it is cut, using interlocking tooth cutting method to replace the initial symmetrical cutting method in order to avoid the resonance produced in the cutting process and improve stability. The exciting frequency when cutting can be improved and the probability of resonance when cutting is lowered. All these ensure high efficiency and high stability cutting.

Design for NGW Type Planetary Gear Transmission

2012 ◽  
Vol 479-481 ◽  
pp. 876-879
Author(s):  
Xian Zhi Li ◽  
Bao Lin Yin ◽  
Chun Shan Liu ◽  
Si Yu Chen
Keyword(s):  
Computer Program ◽  
Optimization Model ◽  
Optimization Design ◽  
Planetary Gear ◽  
Gear Transmission ◽  
Transmission Mechanism ◽  
Design Parameters ◽  
Boundary Constraint ◽  
And Mathematics ◽  
Drawing Program

This article analyzes the NGW type planetary gear transmission mechanism and structure, establishes boundary constraint conditions and mathematics optimization model in view of the smallest volume's project objective. It can realize the NGW type planetary gear transmission optimization design through compiling corresponding computer program, obtain the optimization design parameters. In optimization design's foundation, it applies the CAD technology to establish drawing program, realizes the parametric drawing.

Numerical Simulation of the Flow Field in Safety Valve

2012 ◽  
Vol 472-475 ◽  
pp. 1432-1436
Author(s):  
Xiao Bin Ji ◽  
Xue Yi Qi ◽  
Xiao Yan Li ◽  
Wan Bin Jin
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Reynolds Number ◽  
Flow Field ◽  
Field Distribution ◽  
Safety Valve ◽  
Structural Parameters ◽  
Flow Noise ◽  
Simulating Calculation

By using the Reynolds stress turbulence model at big Reynolds number condition and computational fluid dynamics, the data simulating calculation was carried out to the safety valve inner flow field with different opening size and different valve structural parameters. The result were showed in visual graphics , and the study showed that the valve structural parameters impact on the flow field distribution , the cavitation creation and the flow noise greatly.

Analysis of the Flow Field and Structure Optimization in Gas-Liquid-Solid Three-Phase Hydrocyclone

2014 ◽  
Vol 533 ◽  
pp. 17-20
Author(s):  
De Hai Chen ◽  
Ming Hu Jiang ◽  
Li Xin Zhao ◽  
Yong Zhang
Keyword(s):  
Flow Field ◽  
Optimization Design ◽  
Structural Parameters ◽  
Structure Optimization ◽  
Technical Support ◽  
Inverted Cone ◽  
Three Phase ◽  
Outlet Hole ◽  
Simulation Results ◽  
Hole Structure

The flow field of gas-liquid-solid three-phase hydrocyclone was analyzed by using the software FLUNET. We have researched different structural parameters on the effect of degassing and degritting. The result shows that the change of inverted cone length ratio, inverted cone diameter, the form of liquid outlet hole structure and the angle of vent structure have some influence on degassing and degritting. Simulation results provides a good technical support for the optimization design of three-phase hydrocyclone structure.

scholarly journals Thermal performance analysis and optimization design of dry type air core reactor with the double rain cover

2021 ◽  
pp. 67-67
Author(s):  
FaTing Yuan ◽  
Shouwei Yang ◽  
Shihong Qin ◽  
Kai Lv ◽  
Bo Tang ◽  
...  
Keyword(s):  
Finite Element ◽  
Temperature Distribution ◽  
Temperature Rise ◽  
Optimization Design ◽  
Orthogonal Experiment ◽  
Structural Parameters ◽  
Fluid Velocity ◽  
Optimization Method ◽  
Design Parameters ◽  
Air Core

In this paper, a fluid-thermal coupled finite element model is established according to the design parameters of dry type air core reactor. The detailed temperature distribution can be achieved, the maximum error coefficient of temperature rise is only 6% compared with the test results of prototype, and the accuracy of finite element calculate method is verified. Taking the equal height and heat flux design parameters of reactor as research object, the natural convection cooling performance of reactor with and without the rain cover is investigated. It can be found that the temperature rise of reactor is significantly increased when adding the rain cover, and the reasons are given by analyzing the fluid velocity distribution of air dcuts between the encapsulation coils. In order to reduce the temperature rise of the reactor with the rain cover, the optimization method based on the orthogonal experiment design and finite element method is proposed. The six factors of the double rain cover are given, which mainly affect the temperature rise of reactor, and the five levels are selected, the influence curve and contribution rate of each factor on the temperature rise of reactor are analyzed. The results show that the contribution ratio of the parameter H1, L1 and L2, are obviously higher than the parameter H2, L3 and ?, so the more attention should be paid in the design of double rain cover. Meanwhile, the optimal structural parameters of rain cover are given based on the influence curves, and the temperature rise is only 43.25?C. The results show that the optimization method can reduce the temperature rise of reactor significantly. In addition, the temperature distribution of inner encapsulations coils of reactor are basically the same, the current carrying capacity of coils can be fully utilized, which provides an important guidance for the optimization design of reactor.

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