Study of radial flow mode magnetorheological energy absorber with center drain hole

2018 ◽  
Vol 27 (10) ◽  
pp. 105008 ◽  
Author(s):  
Zhuqiang Li ◽  
Changrong Liao ◽  
Bengyuan Fu ◽  
Xiaochun Jian ◽  
Mengjie Shou ◽  
...  
2018 ◽  
Vol 30 (1) ◽  
pp. 127-139 ◽  
Author(s):  
Benyuan Fu ◽  
Changrong Liao ◽  
Zhuqiang Li ◽  
Lei Xie ◽  
Xiaochun Jian ◽  
...  

High-viscosity linear polysiloxane–based magnetorheological fluid features its excellent suspension stability. Few reports could be found for magnetorheological energy absorbers using such highly viscous but highly stable magnetorheological fluids as the controlled medium. This study presents a design strategy for the high-viscosity linear polysiloxane–based magnetorheological fluid–based magnetorheological energy absorber with multi-stage radial flow mode. The design strategy is based on the Herschel–Bulkley flow model incorporating minor losses proposed in our prior work. The optimal geometrical parameters were obtained by gradually reducing the number of unknown variables. By analyzing the effect of thicknesses of baffle and outer cylinder and number of coil turns on magnetic circuit, the distribution of magnetic flux in the effective region of magnetorheological valve was optimized. Furthermore, a magnetorheological energy absorber was fabricated and tested using a high-speed drop tower facility with a 600 kg mass. The maximum nominal impact velocity was 4.2 m/s, and the applied current varied discretely from 0, 1, 2, to 3 A. Comparison of our Herschel–Bulkley flow model with measured data was conducted via analysis of peak force, dynamic range, and maximum displacement that indicate the performance of magnetorheological energy absorber. The results validated the effectiveness of the design strategy for the high-viscosity linear polysiloxane–based magnetorheological fluid–based magnetorheological energy absorber.


2017 ◽  
Vol 26 (2) ◽  
pp. 025025 ◽  
Author(s):  
Benyuan Fu ◽  
Changrong Liao ◽  
Zhuqiang Li ◽  
Lei Xie ◽  
Peng Zhang ◽  
...  

Molecules ◽  
2021 ◽  
Vol 26 (22) ◽  
pp. 7059
Author(s):  
Benyuan Fu ◽  
Xianming Zhang ◽  
Zhuqiang Li ◽  
Ruizhi Shu ◽  
Changrong Liao

The excellent suspension stability of the high-viscosity linear polysiloxane magnetorheological fluid (HVLP MRF) makes it a great controlled medium for magnetorheological energy absorbers (MREAs). In our previous work, the Herschel–Bulkley flow model (HB model) was used to describe the shear-thinning rheological behavior and establish the dynamic model of an HVLP MRF-based MREA with radial flow mode. However, as the established model was implicit, the MREA response time increased and the buffer effect was degraded. To improve the time response characteristics, an explicit dynamic model based on the HB model incorporating minor losses (called the E-HBM model) is proposed in this study. The model parameters were identified based on the HBM model. To verify the E-HBM model, five evaluation parameters for the energy absorption performance of the MREA, that is, peak force, mean force, crush force efficiency, specific energy absorption, and stroke efficiency, were introduced to compare the theoretical results with the experimental results obtained using a high-speed drop tower facility with a mass of 600 kg. Then, the relative error of the crush force efficiency, specific energy absorption, and stroke efficiency was quantitatively and comprehensively analyzed considering the E-HBM model and experimental results. The results indicate that the proposed E-HBM model agrees with the impact behavior of the radial flow mode MREA.


2009 ◽  
pp. 141-151 ◽  
Author(s):  
G. Cavazzini ◽  
G. Pavesi ◽  
G. Ardizzon ◽  
P. Dupont ◽  
S. Coudert ◽  
...  

2003 ◽  
Vol 780 ◽  
Author(s):  
P. Thomas ◽  
E. Nabighian ◽  
M.C. Bartelt ◽  
C.Y. Fong ◽  
X.D. Zhu

AbstractWe studied adsorption, growth and desorption of Xe on Nb(110) using an in-situ obliqueincidence reflectivity difference (OI-RD) technique and low energy electron diffraction (LEED) from 32 K to 100 K. The results show that Xe grows a (111)-oriented film after a transition layer is formed on Nb(110). The transition layer consists of three layers. The first two layers are disordered with Xe-Xe separation significantly larger than the bulk value. The third monolayer forms a close packed (111) structure on top of the tensile-strained double layer and serves as a template for subsequent homoepitaxy. The adsorption of the first and the second layers are zeroth order with sticking coefficient close to one. Growth of the Xe(111) film on the transition layer proceeds in a step flow mode from 54K to 40K. At 40K, an incomplete layer-by-layer growth is observed while below 35K the growth proceeds in a multilayer mode.


2019 ◽  
Author(s):  
Valentin Smeets ◽  
Ludivine van den Biggelaar ◽  
Tarek Barakat ◽  
Eric M. Gaigneaux ◽  
Damien Debecker

Self-standing macrocellular titanosilicate monolith foams are obtained using a one-pot sol-gel route and show excellent performance in the epoxidation of cyclohexene. Thanks to the High Internal Phase Emulsion (HIPE) templating method, the materials feature a high void fraction, a hierarchically porous texture and good mechanical strength. Highly dispersed Ti species can be incorporated in tetrahedral coordination the silica matrix. These characteristics allow the obtained ‘SiTi(HIPE)’ materials to reach high catalytic turnover in the epoxidation of cyclohexene. The monoliths can advantageously be used to run the reaction in continuous flow mode.<br>


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