scholarly journals Simulation analysis of underwater working condition of ship rudder blade based on Fluent

2021 ◽  
Vol 2108 (1) ◽  
pp. 012006
Author(s):  
Haowei Zhao ◽  
Guifeng Liu ◽  
Jianggui Han
Keyword(s):  
Numerical Calculation ◽  
Power Plant ◽  
Working Conditions ◽  
Working Condition ◽  
Simulation Analysis ◽  
Normal Operation ◽  
Damage And Failure ◽  
Influence Of Water ◽  
Simulation Results ◽  
Numerical Calculation Method

Abstract The rudder blade is an important power plant of the ship. Removing damage and failure is the premise of the normal operation of the ship. In this paper, the numerical calculation method is used, combined with K-ɛ (k-epsilon model) and S-A (spalart allmaras) turbulence model, the underwater working conditions of ship rudder blade are analyzed, and the influence of water flow impact at different angles of attack on the damage failure of rudder blade components is discussed. The simulation results show that when the ship is sailing at constant speed, with the change of water attack angle, the main distribution range of rudder blade stress deviates, and the lift and resistance of rudder blade are also gradually increasing, which is easy to damage the parts with concentrated stress. It has theoretical guiding significance for the protection and repair of rudder blade damage.

Simulation Analysis of Static Characteristics of CJX2-40 Type AC Contactor Electromagnetic Mechanism

2014 ◽  
Vol 8 (1) ◽  
pp. 467-473
Author(s):  
Jiaxian Li
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Calculation ◽  
Boundary Value Problems ◽  
Simulation Analysis ◽  
Boundary Value ◽  
Simulation Method ◽  
Limited Range ◽  
Numerical Calculation Method ◽  
Element Method

At present, the finite element method has been widely used in electrical engineering; value has an absolute advantage in the field of solving the problem of position in the electromagnetic boundary. From the perspective of historical development, for solving the electromagnetic boundary value problems, four kinds of methods are used namely; graphical method, simulation method, analytical method and numerical calculation . This study introduced finite element method which has developed rapidly. Before finite element method, numerical calculation method was used, although this method was effective to a certain extent but the results showed that it had a limited range of the electromagnetic boundary value problems to be solved.

Simulation Analysis of Upper Mould Base for High Speed Punch

2011 ◽  
Vol 101-102 ◽  
pp. 427-430
Author(s):  
Rui Yin Song ◽  
Mei Qin Zhang ◽  
Chen Tang ◽  
Lei Li
Keyword(s):  
High Speed ◽  
Working Condition ◽  
Simulation Analysis ◽  
Simulation Models ◽  
Frequency Condition ◽  
Temperature Changes ◽  
Thermal Boundary Conditions ◽  
Mould Base ◽  
Simulation Results ◽  
Set Up

Based on two kinds of upper mould bases real structures of high speed punch, the structure was simplified and simulation models were built in next step. According to working condition of actual temperature changes and moving characteristics for the high speed punch, the thermal boundary conditions, the thermal- stress coupling conditions and mechanical constraint conditions of the simulation model were set up, and the deformation for the guiding hole of upper mould base were got through simulation analysis. Through the comparison of the two simulation results, it illustrated that the improved upper mould base is more suitable for high speed punch with high punch frequency condition.

Flow Filed Simulation Analysis of Nearly Balanced Drilling Mechanism

2011 ◽  
Vol 109 ◽  
pp. 232-236
Author(s):  
Xin Hua Yi ◽  
Xiao Min Cheng ◽  
Hong Chao Fan
Keyword(s):  
Numerical Simulation ◽  
Working Condition ◽  
Pressure Field ◽  
Pressure Effect ◽  
Simulation Analysis ◽  
Design Method ◽  
Structure Design ◽  
Negative Effect ◽  
Design Requirements ◽  
Simulation Results

In order to eliminate the negative effect of pressure effect-continuation effect and not to affect drilling liquid washing the bottom of hole in nearly balanced drilling. This paper mainly presents the structure design method based on the nearly balanced drilling device theory, makes use of numerical simulation technology to analyze accurately the flow filed of drilling liquid in the certain working condition and uses k-ε model to simulation this problem. Simulation results show the pressure field and velocity field is consistent with the design requirements.

Study of HVDC System and Subsynchronous Oscillation

2015 ◽  
Vol 1092-1093 ◽  
pp. 356-361
Author(s):  
Peng Fei Zhang ◽  
Lian Guang Liu
Keyword(s):  
Power Plant ◽  
Time Domain ◽  
Simulation Method ◽  
Time Domain Simulation ◽  
Stable Convergence ◽  
Turbine Generator ◽  
Plant Model ◽  
Subsynchronous Oscillation ◽  
Hvdc System ◽  
Simulation Results

With the application and development of Power Electronics, HVDC is applied more widely China. However, HVDC system has the possibilities to cause subsynchronous torsional vibration interaction with turbine generator shaft mechanical system. This paper simply introduces the mechanism, analytical methods and suppression measures of subsynchronous oscillation. Then it establishes a power plant model in islanding model using PSCAD, and analyzes the effects of the number and output of generators to SSO, and verifies the effect of SEDC and SSDC using time-domain simulation method. Simulation results show that the more number and output of generators is detrimental to the stable convergence of subsynchronous oscillation, and SEDC、SSDC can restrain unstable SSO, avoid divergence of SSO, ensure the generators and system operate safely and stably

Feature extraction method of pipeline signal based on parameter optimized vocational mode decomposition and exponential entropy

2021 ◽  
pp. 014233122110294
Author(s):  
Yina Zhou ◽  
Yong Zhang ◽  
Jingyi Lu ◽  
Fan Yang ◽  
Hongli Dong ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Working Conditions ◽  
Acoustic Signals ◽  
Normal Operation ◽  
Local Characteristic ◽  
Support Vector ◽  
K Value ◽  
Feature Vectors ◽  
Mode Decomposition ◽  
Exponential Entropy

Pipeline leakage is the main reason that affects normal operation of the pipeline. In this paper, a feature recognition method for pipeline acoustic signals based on vocational mode decomposition (VMD) and exponential entropy (EE) is investigated, which could extract the characteristics of pipeline signals and further accurately identify the pipeline acoustic signals under different working conditions. First, the VMD is used to decompose the collected acoustic signals into a number of mode components, during which process the optimal mode number (i.e., K-value) is determined by combining local characteristic scale decomposition (LCD) and correlation analysis methods. Then, the characteristic content of each mode component is analyzed with the help of the determined correlation coefficient (CC) threshold. If the correlation coefficient of a mode component is greater than the threshold, then the mode component is selected as the feature component. Subsequently, the EE values of the selected feature components are calculated to form the feature vectors corresponding to different kinds of pipeline signals. Finally, the feature vectors are input into support vector machine (SVM) to classify and recognize the different pipeline states. The experimental results demonstrate that the proposed method can identify the pipeline signals under different working conditions, and the recognition accuracy is up to [Formula: see text]. By analyzing and comparing with methods of EE-SVM, original data-SVM, VMD-singular spectrum entropy (SSE) and VMD-information entropy (IE), it is further verified that the proposed method is feasible and superior to the methods.

Rough Sets Based Simplified Analysis of Energy Loss Indicators in Power Plant

2011 ◽  
Vol 383-390 ◽  
pp. 4130-4133
Author(s):  
Song Feng Tian ◽  
Wei Wang ◽  
Yun Feng Tian ◽  
Shuang Bai Liu
Keyword(s):  
Power Plant ◽  
Energy Loss ◽  
Rough Sets ◽  
Power Plants ◽  
Working Condition ◽  
Thermal Power ◽  
Thermal Power Plants ◽  
Optimal Management ◽  
Loss Analysis ◽  
Key Indicators

There are many kinds of energy loss indicators in power plant, and there are some relevance among the various indicators. So extraction of the key indicators plays an important role between in energy loss analysis of power plants and optimal management of thermal power plants. Based on the characteristics of these indicators, the idea of rough sets was applied to the energy loss analysis of thermal power plants, then we proposed a new algorithm -- use fuzzy C means algorithm (FCM) to discrete cluster the energy loss indicators of thermal power plant, and then analysis simplified the results with algorithm Johnson. Real experiments (Chaozhou 1,2 and Ningde 3,4 assembling units which of the same type in the SIS system under the THA working condition)’ results had proved high accuracy and valuable of the algorithm.

Determination Method of Elasto-Plastic Correction Factor of TA16 Titanium Alloy Based On RCC-M Code Methodology

2021 ◽  
Author(s):  
Xuejiao Shao ◽  
Juan Du ◽  
Liping Zhang ◽  
Hai Xie ◽  
Jun Tian ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Titanium Alloy ◽  
Numerical Calculation ◽  
Austenitic Stainless Steel ◽  
Constitutive Model ◽  
Correlation Coefficient ◽  
Correction Factor ◽  
Calculation Method ◽  
Plastic Correction ◽  
Numerical Calculation Method

Abstract In the code for nuclear equipment, the elasto-plastic correction factor KE is a correction factor when the stress range exceeds the yield limit for simplified elasto-plastic fatigue analysis. The parameters and expressions of KE for commonly used materials (such as austenitic stainless steel) are given in the RCC-M and ASME code, but the parameters of KE for titanium alloy materials is lacking. Based on the cyclic elasto-plastic constitutive model of Z2CND18.12 (nitrogen control) and KE parameters of austenitic stainless steel given in the code, considering various sensitive factors, a numerical calculation method for determining KE correlation coefficient is established. The elasto-plastic constitutive model of TA16 alloy with nonlinear kinematic hardening was established by the uniaxial tension, strain and stress cycling tests of TA16 titanium alloy. Based on the numerical calculation method of KE and the constitutive model of TA16 titanium alloy, the expression and correlation coefficient of KE for TA16 titanium alloy were determined.

Precise grading of surrounding rock based on the numerical calculation of the jointed rock mass

2022 ◽  
pp. 1-32
Author(s):  
Dan Huang ◽  
Xiao-Qing Li ◽  
Wen-Chao Song
Keyword(s):  
Rock Mass ◽  
Numerical Calculation ◽  
Calculation Method ◽  
Jointed Rock ◽  
Jointed Rock Mass ◽  
Surrounding Rock ◽  
Geological Survey ◽  
Survey Method ◽  
Synthetic Rock ◽  
Numerical Calculation Method

In this study, grading of surrounding rock was based on rock mass basic quality (BQ) values according to the specifications in China. Numerical approach was to construct synthetic rock mass (SRM) model to represent the jointed rock mass, and obtain the strength of the rock mass. It represented intact rock by the bonded particle model (BPM), and represent joint behaviour by the smooth joint model (SJM) to construct the discrete fracture network (DFN). In the Hongtuzhang Tunnel, the micro properties of granite cores with different weathered degrees were determined by the validation process, and the calculation representative elementary volume (REV) of surrounding rock was 15 m×15 m. Five slightly weathered, three slightly to moderately weathered, and two moderately weathered granite surrounding rock mass models were established based on the probability distribution of joint sets in each borehole, the conversion BQ value was acquired according by the calculated strength of rock mass model. It was discussed the differences of surrounding rock grades between the geological survey method and the numerical calculation method, and then found that the geological survey report is higher than the numerical calculation method predicted. And the numerical calculation is consistent with the actual excavation of rock mass at borehole A1388.

Study on operating modes of doubly fed induction generator with a short circuit fault on grid near the wind power plant

2021 ◽  
Vol 15 (1) ◽  
pp. 37-44
Author(s):  
Thai Hiep Le ◽  
◽  
Duong Hoang Phuc Tran
Keyword(s):  
Power Plant ◽  
Short Circuit ◽  
Active Power ◽  
Induction Generator ◽  
Wind Power Plant ◽  
Doubly Fed Induction Generator ◽  
Power Characteristic ◽  
Simulation Results ◽  
Doubly Fed ◽  
Short Circuit Fault

In this paper, the operating mode of a doubly fed induction generator (DFIG) wind turbine is studied in order to evaluate its fault ride-through and transient stability with a grid’s short circuit fault at near the wind power plant. Based on the structure of DFIG, external resistors are directly connected to rotor windings, then the generator operates as a wound rotor induction generator (WRIG) when there is a short circuit fault on the grid. According to the simulation results in Matlab, the active power is consumed on the crowbar resistor, causing the active power characteristic of generator is changed from high to low. As a result, the amount of excess mechanical energy is not much, so the generator be not accelerated significantly. These simulation results show that it is appropriate to use the crowbar resistor to change the power characteristic of the DFIG. Thanks to this change, the generator is still connected to the grid, stable operation both during and after a short circuit.

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