Theoretical study and experimental validation on the energy dissipation mechanism of particle dampers

2017 ◽  
Vol 25 (4) ◽  
pp. e2125 ◽  
Author(s):  
Zheng Lu ◽  
Biao Huang ◽  
Ying Zhou
2016 ◽  
Vol 24 (4) ◽  
pp. 682-693
Author(s):  
Jianglong Fang ◽  
Xiaopeng Wang ◽  
Tianning Chen ◽  
Kai Zhang

To study the energy dissipation mechanism of nonobstructive particle dampers (NOPDs) and provide guidance to the application of NOPDs, the dense granular flow theory was introduced to establish a quantitative energy dissipation model for NOPDs. The convection movement of the particles under vibrational excitations was studied using the discrete element method, and the Prandtl mixing length theory was adopted to modify the constitution law of dense granular flows. The pressure of the granular flow was obtained by equivalenting the vibrational excitation to a body force acted on particles. Theoretical results showed that the energy dissipation rate of the NOPD was increased with the vibration intensity and decreased with the granular diameter. It also indicated that particles near the side wall and the bottom of the damper dissipated more energy than those particles in other regions. The theoretical model was verified by simulation and experimental result. The results may provide a new approach to studying the energy dissipation mechanism of NOPD and give some guidance to enhancing the damping performance of NOPD in engineering practices.


2019 ◽  
Vol 163 ◽  
pp. 107532 ◽  
Author(s):  
Kaijin Wu ◽  
Zhijun Zheng ◽  
Shuaishuai Zhang ◽  
Linghui He ◽  
Hongbin Yao ◽  
...  

2015 ◽  
Vol 17 (36) ◽  
pp. 23468-23480 ◽  
Author(s):  
Sundaram Arulmozhiraja ◽  
Naoki Nakatani ◽  
Akira Nakayama ◽  
Jun-ya Hasegawa

Triplet energy dissipation mechanism of a carotenoid: just bond twisting and stretching lead to minimum energy intersystem crossing point.


Author(s):  
Qinghua Yang ◽  
Qian Yang

Abstract The baffle drop shaft is widely used in deep tunnel drainage system due to its fine applicability and high energy dissipation. To fully study the turbulence characteristics and energy dissipation mechanism of baffle drop shafts, a 1:25 scale physical model test and the numerical simulation based on the Realizable k-ε model and Volume of Fluid (VOF) method were performed. The results showed that a baffle spacing that is too dense or too sparse is not conducive to energy dissipation and discharge. The minimum baffle spacing is the optimal structural design at the design flow rate when the flow regime is free-drop flow. The energy dissipation calculation model established in this paper has high accuracy for calculating the energy dissipation rate on the baffles in free-drop flow. The energy dissipation modes of the shaft can be divided into inlet energy dissipation, baffle energy dissipation, and shaft-bottom energy dissipation. Baffles play a major role in the energy dissipation at low flow rates, and the proportions of inlet and shaft-bottom energy dissipation increase with the increase in flow rate.


2021 ◽  
pp. 151673
Author(s):  
Ahmed A. Tiamiyu ◽  
Xi Chen ◽  
Edward L. Pangv ◽  
Yuchen Sun ◽  
Jasper Z. Lienhard ◽  
...  

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