Numerical Simulation and Experimental Research on Pedestal Looseness of a Rotor System

2007 ◽  
Author(s):  
Hui Ma ◽  
Hong Liang Yao ◽  
Zhao Hui Ren ◽  
Feng Wen ◽  
Bang Chun Wen
Keyword(s):  
Numerical Simulation ◽  
Mechanical Model ◽  
Test Rig ◽  
Rotating Speed ◽  
Runge Kutta Method ◽  
Motion State ◽  
Simulation And Experiment ◽  
State Changes ◽  
Simulation Results ◽  
Set Up

The mechanical model of looseness of fastening bolt on the bearing pedestal is set up based on the project practice. Using the nonlinear oil-film model put forward by Adiletta, the dynamic characteristics were investigated by numerical Runge-Kutta method. At last, the experiment is performed to investigate the pedestal looseness by a test rig and the fault signals are analyzed by the spectrum cascade and reassigned wavelet scalogram. Numerical simulation and experiment all show that system motion state changes frequently with the increase of the rotating speed. And the experimental results coincide with the simulation results.

scholarly journals An Investigation of Dynamic Responses and Head Injuries of Standing Subway Passengers during Collisions

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Yong Peng ◽  
Tuo Xu ◽  
Lin Hou ◽  
Chaojie Fan ◽  
Wei Zhou
Keyword(s):  
Numerical Simulation ◽  
Head Injury ◽  
Head Injuries ◽  
Dynamic Responses ◽  
Passive Safety ◽  
Friction Coefficients ◽  
Safety Design ◽  
Parametric Studies ◽  
Simulation Results ◽  
Set Up

With the development of the subway and the pressing demand of environmentally friendly transportation, more and more people travel by subway. In recent decades, the issues about passenger passive safety on the train have received extensive attention. In this research, the head injury of a standing passenger in the subway is investigated. Three MADYMO models of the different standing passenger postures, defined as baseline scenarios, are numerically set up. HIC15values of passengers with different postures are gained by systematic parametric studies. The injury numerical simulation results of various scenarios with different friction coefficients, collision acceleration, standing angle, horizontal handrail height, and ring handrail height are analyzed. Results show that the horizontal handrail provides better protection in the three different standing passenger postures. Different friction coefficients and the standing angle have great impact on the head injuries of passengers in three different scenarios. The handrail height also has some effects on head injury of passengers with different standing postures, so it is necessary to be considered when designing the interior layout of the subway. This study may provide guidance for the safety design of the subway and some advices for standing subway passengers.

Research on the Numerical Simulation of Silting in Floodplain and Scouting in Main Channel of Over-Bank Flooding in the Lower Yellow River

2011 ◽  
Vol 255-260 ◽  
pp. 3692-3696
Author(s):  
Xiao Lei Zhang ◽  
Dong Po Sun ◽  
Feng Ran Zhang
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Yellow River ◽  
Main Channel ◽  
River Channel ◽  
Lower Yellow River ◽  
The Lower Yellow River ◽  
Water And Sediment ◽  
Simulation Results ◽  
Set Up

The 2-D water and sediment mathematical model which reflects silting in floodplain and scouting in main channel of over-bank flooding in the Lower Yellow River has been set up in this paper. Through carrying on 2-D water and sediment numerical simulation of the “96.8” typical flood, the author studied influence of over-bank flooding on flood travel and transverse exchange. The primary simulation results show that, adopting the over-bank flooding for silting in floodplain and scouting in main channel effectively guaranteed and expanded transverse exchange between floodplain and main channel and maintained the river channel vigor. This can relieve “secondary suspended river” states in the Low Yellow River to a certain extent; at the same time, the different magnitudes of over-bank floods have different effect of silting in floodplain and scouting in main channel.

scholarly journals Numerical Simulation and Experimental Study on Shaped Charge Warhead of Guided Ammunition

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Guangsong Ma ◽  
Guanglin He
Keyword(s):  
Numerical Simulation ◽  
Cone Angle ◽  
Shaped Charge ◽  
Liner Material ◽  
Penetration Ability ◽  
Simulation And Experiment ◽  
Control Section ◽  
Simulation Results ◽  
And Control ◽  
Shaped Charge Jet

To study the jet penetration capability of shaped charge warhead of guided ammunition, a variable cone angle-shaped charge liner was designed. LS-DYNA software is used to simulate the penetration capability of shaped charge warhead with three different metal materials (copper, steel, and aluminum). Numerical simulation results show that the velocity of the shaped charge jet formed by the three kinds of materials is v aluminum > v copper > v steel , and the residual velocity after penetration is V steel > V aluminum > V copper , the time when the jet starts to break is tcopper > tsteel > taluminum, and the penetration completion time is Tcopper < Taluminum < Tsteel; therefore, according to the numerical simulation results, copper was selected as the liner material, and the principle prototype is made for the experiment. The results of numerical simulation and experiment show that the shaped charge warhead with copper shaped charge liner has good penetration ability and after-effect damage ability to steel target after penetrating the guidance section, steering gear section, and control section.

Virtual Prototype Co-Simulation of 4WS Vehicle

2011 ◽  
Vol 328-330 ◽  
pp. 408-411
Author(s):  
Wei Wei Wang ◽  
Jian Feng Xu
Keyword(s):  
Control System ◽  
Physical Model ◽  
Mechanical Model ◽  
Theoretical Basis ◽  
Virtual Prototype ◽  
Lane Change ◽  
Vehicle Model ◽  
Response Curves ◽  
Simulation Results ◽  
Set Up

A new 4WS vehicle model is set up by means of revamping a foreign FWS model. Co-simulation is completed by loading 4WS mechanical model as a subsystem which is built to express the characteristics of physical model of vehicle in ADAMS/Car into the control system modeled in MATLAB. Moreover, the response curves of evaluating handling stability are obtained according to co-simulation results of step steering maneuvers and single lane change maneuvers. It provides theoretical basis for developing 4WS physical vehicle rapidly.

Study on the Porous Media Used in Numerical Simulation of Temperature Characteristic for Isothermal Chambers

2011 ◽  
Vol 291-294 ◽  
pp. 1689-1692
Author(s):  
Li Hong Yang ◽  
Da Hua Liu
Keyword(s):  
Numerical Simulation ◽  
Porous Medium ◽  
Porous Media ◽  
Flow Rate ◽  
Temperature Characteristic ◽  
Test Results ◽  
Temperature Characteristics ◽  
Simulation And Experiment ◽  
Simulation Results ◽  
Metal Wires

Isothermal chamber, which is fabricated by empty chamber stuffed with thin metal wires, is a kind of test devices for flow rate characteristics of pneumatic components, and its temperature characteristics are critical to the accuracy of test results. In this paper, the stuffers in isothermal chamber were considered as porous medium with large porosity, so the temperature characteristics could be studied by numerical simulation. Though there are differences between simulation and experiment, they have same trends and the law of variation can be seen from the simulation results, which demonstrates the reliability of numerical simulation. Consequently, simulation can be an efficient method, which is energy-saving and cost-reducing.

Simulation and Experimental Study on the Impact of Breadth of Back Blade on Axial Force Balance

2011 ◽  
Vol 130-134 ◽  
pp. 1568-1572
Author(s):  
Hui Wang ◽  
Jie Gang Mu ◽  
Miao Yin Su ◽  
Shui Hua Zheng ◽  
Jin Jing Zhao ◽  
...  
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Experimental Study ◽  
Axial Force ◽  
Three Dimensional ◽  
Force Balance ◽  
Simulation And Experiment ◽  
Simulation Results ◽  
The Impact ◽  
The Relationship

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.

Optimization and Numerical Simulation of Locking Mechanism

2014 ◽  
Vol 494-495 ◽  
pp. 725-728
Author(s):  
De Yong Cai ◽  
Fu Jun Liu ◽  
Gong Min Tang
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Mechanical Model ◽  
The Finite Element Method ◽  
Working Process ◽  
Optimization Result ◽  
Locking Mechanism ◽  
Design Requirements ◽  
Simulation Results

The mechanical model of a new spring locking mechanism was established. The optimum spring parameters of the locking mechanism which meet the design requirements were provided by optimization. Using the finite element method, numerical simulation of working process of the locking mechanism was carried out. The rationality of optimization result was verified by simulation results of numerical simulation.

Research on Numerical Simulation of Quad Bundle Conductor on Galloping

2013 ◽  
Vol 457-458 ◽  
pp. 23-27
Author(s):  
Xue Ping Zhan ◽  
Kuan Jun Zhu ◽  
Cao Lan Liu ◽  
Bin Liu ◽  
Jun Zhang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Numerical Results ◽  
Kutta Method ◽  
Aerodynamic Parameter ◽  
Runge Kutta Method ◽  
Simulation Results ◽  
Runge Kutta ◽  
Element Method

The models of the multi-bundled conductors are constructed by finite element method in this paper. The numerical results are given by using the 4th order Runge-Kutta method considering aerodynamic parameter of sub-conductor. The simulation results are obtained on galloping of quad bundle conductors with the different span. Thus some effective numerical results of quad twin bundle conductor can provide a useful reference for anti-galloping design.

Design and Simulation Research on Mechanical Ventilation System for Small Underground Granary

2014 ◽  
Vol 875-877 ◽  
pp. 2148-2151
Author(s):  
Hai Hong Zhang ◽  
Zhong Ying Wang ◽  
Qiang Liu ◽  
Peng Fei Ma
Keyword(s):  
Numerical Simulation ◽  
Mechanical Ventilation ◽  
Pressure Field ◽  
Ventilation System ◽  
Simulation Research ◽  
New Type ◽  
Simulation Results ◽  
Dynamic Numerical Simulation ◽  
Set Up ◽  
Better Than

The mechanical ventilation system of new type underground granary was designed and three wind pipe models with different length were investigated in this paper. Dynamic numerical simulation was applied for evaluating the cooling effect of mechanical ventilation of the granary. The simulation results, including temperature field, flow field and pressure field results, show that the cone shaped base of grain granary is better than flat shaped base. It is an optimal project that the main wind pipe opens with mesh only in the bottom. In addition, four vertical guide plates were set up around the main wind pipe, which have the function of saving energy and reducing consumption.

Effects of rotational speed on the leakage behavior, temperature increase, and swirl development of labyrinth seal in a compressor stator well

2016 ◽  
Vol 231 (13) ◽  
pp. 2362-2374 ◽  
Author(s):  
Gaowen Liu ◽  
Xiaozhi Kong ◽  
Yuxin Liu ◽  
Qing Feng
Keyword(s):  
Flow Characteristics ◽  
Internal Flow ◽  
Labyrinth Seal ◽  
Swirl Flow ◽  
Tip Clearance ◽  
Experimental Results ◽  
Test Rig ◽  
Experimental Conditions ◽  
Rotating Speed ◽  
Set Up

The stator well in a compressor is the space between the rotor and stator inside the mainstream annulus flow. Labyrinth seals are normally used to control the internal flow in the stator well. The upstream and downstream rotating cavities of the labyrinth seal can lead to substantial temperature rise and swirl development in this region. Additionally, due to the centrifugal expansion and thermal expansion, the tip clearance of labyrinth seal changes dramatically at different rotational speeds and temperatures in the stator well. A test rig capable to establish different rotational speeds and pressure ratios was designed according to the simplified model of the labyrinth seal in a compressor stator well (one stage). The leakage flow rate and change in total temperature across the stator well were measured. This paper also contains the experimental results of swirl ratios in the outlet rotating cavity to reveal the swirl development. Special emphasis in this work lies on acquiring the working tip clearance precisely. The set up tip clearance was measured with plug gauges, while the radial displacements of labyrinth ring and stator casing were measured separately with two high precision laser distance sensors. Two-dimensional, axisymmetric swirl flow numerical simulations were performed to get a further understanding about the basic flow characteristics and to evaluate their ability to predict the experimental results. The computational results of discharge coefficient, windage heating, and swirl ratio were compared to those obtained from test rig measurements. Particularly, when calculating, the tip clearance, the inlet parameters, and the outlet parameters of numerical model at a specific rotating speed were set to be the same with the experimental conditions.

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