Analysis on the Effect of Bend Curve Radius to Inherent Characteristics of the U-Tubes

2012 ◽  
Vol 490-495 ◽  
pp. 355-359
Author(s):  
Li Na Zhang ◽  
Zhen Yu Ma ◽  
Min Shan Liu
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Resonance Frequency ◽  
Natural Frequency ◽  
Vibration Frequency ◽  
Bend Radius ◽  
First Order ◽  
Transfer Tube ◽  
Shaped Tube ◽  
Curve Radius

For large-capacity steam generator, piping zone diameter of U-tube section is nearly 5m, the range of U-shaped bend radius is very large from Zero meters to 2.5 meters, this affects obviously the Vibration characteristics of heat transfer tube, this effect is researched using numerical simulation. Engineering formulas of natural frequency of U-shaped tube under different conditions are given. According the vibration-type, The lowest natural frequency of U-shaped tube is plane vibration frequency of the first order for adding one anti-vibration bar or not. Natural frequency of U-shaped tube increases significantly adding anti-vibration bars to bend, which is favorable to avoid the resonance frequency and severe vibration of U-shaped tube

The Vibration and Modal Analysis of the Disc Brake

2013 ◽  
Vol 774-776 ◽  
pp. 78-81
Author(s):  
Fa Zong Li ◽  
Shui Guang Tong
Keyword(s):  
Numerical Simulation ◽  
Resonance Frequency ◽  
Modal Analysis ◽  
Natural Frequency ◽  
Vibration Mode ◽  
Noise Control ◽  
Simulation Method ◽  
Disc Brake ◽  
At Resonance ◽  
Numerical Simulation Method

The article analyzed the modal of disc brake, the intrinsic characteristics of each disc brake parts were obtained, using modal tests to verify the accuracy of the numerical simulation method; by comparing different vibration mode and natural frequency of the brake parts, predicting the frequency which vibration may occur, aiming at resonance frequency which is easy to occur, improving the structure of the disc brake to improve each order natural frequency, the resonance of the disc brake is effectively reduced, the braking noise was decreased, The study laid a foundation for vibration and noise control of the disc brake.

scholarly journals The Static and Dynamic Sensitivity of Magnetostrictive Bioinspired Whisker Sensor

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Ran Zhao ◽  
Qingjie Yuan ◽  
Jianwu Yan ◽  
Qanguo Lu
Keyword(s):  
Natural Frequency ◽  
Cantilever Beam ◽  
Vibration Frequency ◽  
Experimental System ◽  
High Sensitivity ◽  
First Order ◽  
Dynamic Sensitivity ◽  
Flow Sensing ◽  
Technical Indicator ◽  
Static Sensitivity

Magnetostrictive bioinspired whisker is a new kind of sensor that can realize tactile and flow sensing by utilizing magnetoelastic effect. The sensitivity is a key technical indicator of whisker sensor. The paper presented a new magnetostrictive whisker based on Galfenol cantilever beam, as well as its operation principle. Then, the static and dynamic sensitivity of the whisker sensor was investigated by using a self-made experimental system. The results illustrated that the proposed sensor has a high sensitivity. Its static sensitivity is 2.2 mV/mN. However, its dynamic sensitivity depends on the vibration frequency. When working at the natural frequency of the cantilever beam, the dynamic sensitivity performs an obvious increase—1.3 mV/mN at 3.5 Hz (the first-order natural frequency) and 2.1 mV/mN at 40 Hz (the second-order natural frequency), respectively.

The Analysis on the First Order Vibration Frequency of Post-Tensioned Unbonded Pre-Stress Concrete Beam

2011 ◽  
Vol 105-107 ◽  
pp. 107-111
Author(s):  
Jin Bo Ma ◽  
Li Jun Wang ◽  
Ting Tang
Keyword(s):  
Natural Frequency ◽  
Vibration Frequency ◽  
Linear Correlation ◽  
Vibrational Frequency ◽  
Concrete Beam ◽  
Experimental Results ◽  
Structural Vibration ◽  
First Order ◽  
Post Tensioned

In order to study the influence on structural vibration from pre-stress and eccentricity, a experiment is designed. After analyzing the experimental results of 9 groups of modal tests on a post-tensioned unbonded pre-stress concrete beam, the following conclusions can be drawn: The influences on first order vibration frequency which are caused by eccentricity and pre-stress really exist. The rules of influences brought about by eccentricity and pre-stress on first order vibration frequency are complicated. When the eccentricity is close to the centroid, the linear correlation between the pre-stress and the first natural frequency will be good, on the contrary, the nonlinear will be strengthened. The first order vibrational frequency of the tested beam will go up with the increase of pre-stress.

Numerical simulation of modulated heat transfer tube in laminar flow regime

2014 ◽  
Vol 75 ◽  
pp. 171-183 ◽  
Author(s):  
Zhen Cao ◽  
Jinliang Xu ◽  
Dongliang Sun ◽  
Jian Xie ◽  
Feng Xing ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Laminar Flow ◽  
Flow Regime ◽  
Heat Transfer Tube ◽  
Laminar Flow Regime ◽  
Transfer Tube

Numerical Simulation of Fretting Wear of Heat-Transfer Tubes in Steam Generator Under Random Excitation Forces

2016 ◽  
Author(s):  
Lichen Tang ◽  
Hao Qian ◽  
Yongcheng Xie ◽  
Yi Jing ◽  
Yongzhong Huo
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Simulation Method ◽  
Elastic Stability ◽  
Relative Displacement ◽  
Random Excitation ◽  
Contact Forces ◽  
Fretting Wear ◽  
Contact Points ◽  
Transfer Tube

A numerical simulation method of fretting wear on heat-transfer tube under random excitation is proposed in this paper. Linear springs are used to simulate the in-plane support of anti-vibration Bars (AVBs) to the U-bend tube. The contact forces between the tube and the AVBs are calculated by using FEM random excitation analysis program. And the in-plane relative displacements subjected to turbulence between the tube and the AVBs at each contact points are calculated. The workrate in Archard equation can be calculated by multiplying the contact force, the relative displacement, coefficient of friction and the modal frequency. By using this method, a representative tube is studied. And the effect that the pre-tightening forces between the tube and AVBs had on the fretting wear and the fluid-elastic stability is discussed.

Numerical simulation of micro-crack leakage on steam generator heat transfer tube

2021 ◽  
Vol 382 ◽  
pp. 111385
Author(s):  
Xiaohan Zhao ◽  
Yixiang Liao ◽  
Mingjun Wang ◽  
Kui Zhang ◽  
G.H. Su ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Numerical Simulation ◽  
Steam Generator ◽  
Heat Transfer Tube ◽  
Transfer Tube
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