scholarly journals Scheme optimization for a turbine blade under multiple working conditions based on the entropy weight vague set

2021 ◽  
Vol 12 (1) ◽  
pp. 615-624
Author(s):  
Guodong Yi ◽  
Huifang Zhou ◽  
Yang Wang ◽  
Jingli Wu ◽  
Jundi Wu
Keyword(s):  
Working Conditions ◽  
Simulation Analysis ◽  
Scoring Function ◽  
Optimization Method ◽  
Condition Index ◽  
Entropy Weight ◽  
Shape Deviation ◽  
Vague Set ◽  
Design Scheme ◽  
Blade Shape

Abstract. The deformation of blades under complex loads of multiple working conditions will reduce the energy conversion efficiency. To reduce the deviation of the blade shape in practical working conditions, a combination and optimization method of blade design schemes under multiple working conditions, based on the entropy weight vague sets, is proposed. The sensitivity of each working condition index is analyzed based on the information entropy, and the satisfaction degree of the design scheme based on the design requirements and experiences is described with the vague set. The matching degree of different design schemes for multiple working conditions is quantified according to the scoring function. The combination and optimization of the design scheme are verified by numerical simulation analysis. The results show that the proposed design scheme has a smaller blade shape deviation than the traditional design scheme under multiple working conditions.

scholarly journals The Dynamic Characteristic of a Faulted Rotor System with Multi-Objective Optimization Designed SFD

2019 ◽  
Vol 9 (17) ◽  
pp. 3628 ◽  
Author(s):  
Liang Ma ◽  
Jun Wang ◽  
Guichang Zhang
Keyword(s):  
Fundamental Frequency ◽  
Working Conditions ◽  
Optimization Method ◽  
Rotor System ◽  
Dynamic Responses ◽  
Multi Objective Optimization ◽  
Operational Parameters ◽  
Multi Objective ◽  
Coupling Fault ◽  
Misalignment Fault

As an important part of the turbomachinery, the rotor–bearing system has been upgraded to provide a high rotating speed in order to meet the demand of high power production. With increasing demand for stability, the squeeze film damper (SFD) has been widely used in industrial machinery because it can reduce the vibration amplitude and suppress the external force. Usually, it shows inadaptability under the different working conditions where the SFD parameters didn’t change appropriately. Therefore, the reasonable choice of operational parameters of SFD is the key solution that can provide viscous damping effectively and restrain the nonlinear vibration generated by faults. In this paper, the mathematical model of a rotor-ball bearing-SFD system considering the misalignment fault and misalignment-rubbing coupling fault is built first. Then the dynamic characteristics under typical working conditions (ω = 1000 rad/s) of the faulted rotor are discussed. The vibration attenuation effects of the SFD parameters selected by using the multi-objective optimization method on the dynamic responses are analyzed. The results show that when the rotor system operates under different states, the value and the sensitivity of optimization parameters are altered. With no fault, the amplitude of fundamental frequency decrease 23%. With the misalignment fault, the amplitude of the fundamental frequency decreases by 43.4%, the amplitude of 2× fundamental frequency decreases by 27.5%, and the amplitude of 3× fundamental frequency decreases by 66.7%. With the misalignment-rubbing coupling fault, the amplitude of fundamental frequency reduces by 7.4%, the amplitude of 2× fundamental frequency drops by 51.5%, and the amplitude of 3× fundamental frequency drops by 16.8%. Overall, the feasibility of the optimization method of the variable-structured SFD operational parameters for the faulted rotor system is verified. These parametric analyses are very helpful in the development of a high-speed rotor system and provide a theoretical reference for the vibration control and optimal design of rotating machinery.

scholarly journals Modified Modeling and System Stabilization of Shunt Active Power Filter Compensating Loads with μF Capacitance

Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2084 ◽  
Author(s):  
Yuqi Bing ◽  
Daozhuo Jiang ◽  
Yiqiao Liang ◽  
Chongxi Jiang ◽  
Tianxiang He ◽  
...  
Keyword(s):  
Working Conditions ◽  
Simulation Analysis ◽  
Active Power Filter ◽  
Active Power ◽  
System Model ◽  
Conventional Model ◽  
Shunt Active Power Filter ◽  
Stability Problems ◽  
Power Filter ◽  
Hybrid Controller

The interactions between shunt active power filter (APF) and capacitance load tend to result in stability problems and resonance. The conventional model of a shunt APF is not precise enough to reflect this phenomenon. To address it, this paper proposes a modified shunt APF system model to accurately reflect various stability problems. This paper also studies the mechanism of positive feedback resonance brought by capacitance load and proposes a modified hybrid controller to improve the stable margin of the system, making the shunt APF work stably under different working conditions where there are μF capacitors on the demand side. The correctness and validity of the proposed strategy are verified by simulation analysis and prototype experiments.

Research on Vague Set of Target Threat Information Fusion Algorithm

2014 ◽  
Vol 599-601 ◽  
pp. 1671-1678
Author(s):  
Ke Hu Xu ◽  
Jin Yu Chen ◽  
De Peng Kong ◽  
Pu Fan
Keyword(s):  
Information Fusion ◽  
Scoring Function ◽  
Score Function ◽  
Quantitative Information ◽  
Uncertain Information ◽  
Fusion Technology ◽  
Fusion Algorithm ◽  
Information Process ◽  
Vague Set ◽  
Research Areas

Information fusion technology is one of the most active research areas currently, which is affected by the fact that the computer can only handle quantitative information and the result cannot reflect the actual feature of the target sometimes. This paper makes use of advantages of the vague set in dealing with uncertain information process to establish the target threat sequencing model based on vague set and take both quantitative and qualitative information of target into account. Using the improved scoring function, this paper comes up with the target threat sequence steps based on extreme score function method to provide a better data supporting for the decision-making function of information fusion technology.

The Application of Virtual Prototyping Technology in the Kinematic Analysis of Hydraulic Excavator Working Device

2012 ◽  
Vol 538-541 ◽  
pp. 3235-3239
Author(s):  
Hai Hong Chen ◽  
Jian Ping Zi
Keyword(s):  
Virtual Environment ◽  
Working Conditions ◽  
Kinematic Analysis ◽  
Simulation Analysis ◽  
Virtual Prototyping ◽  
Three Dimensional ◽  
Hydraulic Excavator ◽  
Kinematic Simulation ◽  
Virtual Prototyping Technology ◽  
Working Device

Three-dimensional software Solidworks and ADAMS were combined together to establish the virtual prototyping model of hydraulic excavator working device in this paper. Various real typical working conditions of excavators were simulated in the virtual environment, then kinematic simulation analysis was conducted, and the main mining parameters in different conditions were given, the results provide a basis for the design of excavator working device.

scholarly journals Preparation and performance of sensing material for diethyl ether: Optimization of working conditions by response surface methodology

2020 ◽  
Author(s):  
Wenjuan Zhang ◽  
Fuxiu Yang ◽  
Hong Wang ◽  
Chunxiu Gu ◽  
Yun Lu ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Diethyl Ether ◽  
Working Conditions ◽  
Sol Gel ◽  
Optimization Method ◽  
Impregnation Method ◽  
Sensing Material ◽  
And Performance ◽  
Lower Temperature

Pd doped ZnNi3Al2O7 composite was synthesized by sol-gel and impregnation method. The EDS spectrum and TEM image showed that Pd atoms are uniformly distributed on the surface of ZnNi3Al2O7 with a particle size of less than 50 nm. A sensitive diethyl ether gas sensor based on cataluminescence on the composite at lower temperature than 200℃ was reported. There is a good linear relationship between the luminescence intensity and the concentration of diethyl ether in the range of 0.1-75 mg/m3. The detection limit (3σ) is 0.06 mg/m3. The working conditions optimized by response surface methodology were analytical wavelength of 548.86 nm, reaction temperature of 109.18℃ and carrier gas velocity of 125.88 ml/min, respectively. The sensitivity of the method can be increased by 4.5% under the optimized working conditions. The optimization method is universal for many multi parameter processes.

scholarly journals Advanced Optimization Design of Cross Beams Structure

2014 ◽  
Vol 8 (1) ◽  
pp. 117-123
Author(s):  
Ke Zhang ◽  
Xuan Mu ◽  
Dehong Zhao ◽  
Yuhou Wu
Keyword(s):  
Topology Optimization ◽  
Optimization Design ◽  
Simulation Analysis ◽  
Lightweight Design ◽  
Optimization Method ◽  
Production Costs ◽  
Structure Quality ◽  
Machining Center ◽  
Traditional Structure ◽  
Inherent Frequency

Solid Isotropic Microstructure with Penalization(SIMP) in topology optimization was deeply analyzed, and thus SIMP topology optimization criteria algorithm was deduced. Simulation analysis to the results was also conducted by Ansys, so as the structural lightweight design to machine crossbeams of the HTM series gantry. By verifying, the structure was 3.8% lower than the traditional structure quality, stiffness increased by 16.07%, and the overall inherent frequency was improved. By applying topology optimization method to the design process of the machining center HTM series, ma-terial utilization is improved and production costs were reduced.

scholarly journals Simulation Analysis of a Ventilation System in a Smart Broiler Chamber Based on Computational Fluid Dynamics

Atmosphere ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 315 ◽  
Author(s):  
Shikai Zhang ◽  
Anlan Ding ◽  
Xiuguo Zou ◽  
Bo Feng ◽  
Xinfa Qiu ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wind Velocity ◽  
Working Conditions ◽  
Simulation Analysis ◽  
Ventilation System ◽  
Absolute Error ◽  
Maximum Absolute Error ◽  
Three Dimensional Model ◽  
Mesh Model

In this paper, a CFD (computational fluid dynamics) numerical calculation was employed to examine whether the ventilation system of the self-designed smart broiler house meets the requirements of cooling and ventilation for the welfare in poultry breeding. The broiler chamber is powered by two negative pressure fans. The fans are designed with different frequencies for the ventilation system according to the specific air temperature in the broiler chamber. The simulation of ventilation in the empty chamber involved five working conditions in this research. The simulation of ventilation in the broiler chamber and the simulation of the age of air were carried out under three working conditions. According to the measured dimensions of the broiler chamber, a three-dimensional model of the broiler chamber was constructed, and then the model was simplified and meshed in ICEM CFD (integrated computer engineering and manufacturing code for computational fluid dynamics). Two models, i.e., the empty chamber mesh model and the chamber mesh model with block model, were imported in the Fluent software for calculation. In the experiment, 15 measurement points were selected to obtain the simulated and measured values of wind velocity. For the acquired data on wind velocity, the root mean square error (RMSE) was 19.1% and the maximum absolute error was 0.27 m/s, which verified the accuracy of the CFD model in simulating the ventilation system of the broiler chamber. The boundary conditions were further applied to the broiler chamber model to simulate the wind velocity and the age of air. The simulation results show that, when the temperature was between 32 and 34 °C, the average wind velocity on the plane of the corresponding broiler chamber (Y = 0.2 m) was higher than 0.8 m/s, which meets the requirement of comfortable breeding. At the lowest frequency of the fan, the oldest age of air was less than 150 s, which meets the basic requirement for broiler chamber design. An optimization idea is proposed for the age of air analysis under three working conditions to improve the structure of this smart broiler chamber.

scholarly journals TOPSIS Method for Probabilistic Linguistic MAGDM with Entropy Weight and Its Application to Supplier Selection of New Agricultural Machinery Products

Entropy ◽  
2019 ◽  
Vol 21 (10) ◽  
pp. 953 ◽  
Author(s):  
Jianping Lu ◽  
Cun Wei ◽  
Jiang Wu ◽  
Guiwu Wei
Keyword(s):  
Supplier Selection ◽  
Scoring Function ◽  
Ideal Solution ◽  
Agricultural Machinery ◽  
Topsis Method ◽  
Entropy Weight ◽  
Suitable Alternative ◽  
Attribute Weights ◽  
Multiple Attribute ◽  
Selection Of

In multiple attribute group decision making (MAGDM) problems, uncertain decision information is well-represented by linguistic term sets (LTSs). These LTSs are easily converted into probabilistic linguistic sets (PLTSs). In this paper, a TOPSIS method is proposed for probabilistic linguistic MAGDM in which the attribute weights are completely unknown, and the decision information is in the form of probabilistic linguistic numbers (PLNs). First, the definition of the scoring function is used to solve the probabilistic linguistic entropy, which is then employed to objectively derive the attribute weights. Second, the optimal alternatives are determined by calculating the shortest distance from the probabilistic linguistic positive ideal solution (PLPIS) and on the other side the farthest distance of the probabilistic linguistic negative ideal solution (PLNIS). This proposed method extends the applications range of the traditional entropy-weighted method. Moreover, it doesn’t need the decision-maker to give the attribute weights in advance. Finally, a numerical example for supplier selection of new agricultural machinery products is used to illustrate the use of the proposed method. The result shows the approach is simple, effective and easy to calculate. The proposed method can contribute to the selection of suitable alternative successfully in other selection problems.

scholarly journals Numerical Simulation Analysis of Collapse Process of Isolated Structure in Strong Earthquakes

2018 ◽  
Vol 53 ◽  
pp. 02017
Author(s):  
Yue Ren ◽  
Ruidong Wang ◽  
Wenguang Liu ◽  
Wenfu He
Keyword(s):  
Working Conditions ◽  
Simulation Analysis ◽  
Vertical Direction ◽  
Vertical Displacement ◽  
Bearing Failure ◽  
Peak Acceleration ◽  
Strong Earthquakes ◽  
Set Up ◽  
Abaqus Model ◽  
Collapse Process

In this paper, the Abaqus model of an 8 layer isolation structure is established, and the connector element provided in the software is used to simulate the stiffness multilinearity in the horizontal and vertical direction of the isolation bearing. In the numerical analysis, six kinds of working conditions are set up to compare the vertical displacement, the peak acceleration and the interlayer displacement etc, and the effect of bearing failure on the superstructure is obtained.

Ant Colony Optimization Based Simulation Analysis of Sports Course Achievement Management System

2021 ◽  
Vol 7 (5) ◽  
pp. 1978-1990
Author(s):  
Mingli Chi
Keyword(s):  
Physical Education ◽  
Ant Colony Optimization ◽  
Management System ◽  
Simulation Analysis ◽  
Rapid Development ◽  
Optimization Method ◽  
Ant Colony ◽  
Ant Colony Optimization Algorithm ◽  
School Teaching ◽  
Scientific Platform

Objectives: With the rapid development of computer technology and network technology, school teaching and management also need to keep pace with the development of the times, and information construction is needed in teaching and management. In the process of campus informationization construction, it is required that all links can be developed in a balanced way, and the school should be built into a scientific platform of information education and teaching from both hardware and software aspects. Methods: Sports achievement management system is based on reducing the workload of physical education teachers, improving teaching efficiency, optimizing the process of students’ class selection, enhancing the identification of students taking part in examinations, saving manpower, financial resources and time compared with the traditional registration model. Results: The ant colony optimization algorithm has achieved encouraging results in solving the combinatorial optimization problem that the traditional optimization method is difficult to work. Therefore, using this algorithm to optimize the simulation analysis of the physical education curriculum management system has better matching characteristics. Conclusion: The system has the characteristics of friendly man-machine interface, easy operation, strong compatibility, fast running speed, etc. It has rich reports and powerful query statistics.

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