共查询到19条相似文献,搜索用时 234 毫秒
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被外电场极化而固化的电流变液容易在极板处产生剪切滑移而降低其力学性能.使用抛光、激光打坑、覆盖尼龙网和光刻腐蚀四种方法对极板形貌进行了修饰,并对电流变液的压缩力学性能进行了测试.研究表明,光滑极板和光刻腐蚀柱阵列极板易产生界面滑移而压缩强度较低,粗糙坑阵列和覆盖尼龙网可抑制界面滑移而压缩强度高.极板形貌增强极板附近局部电场强度,强化了链末端与极板间的作用,迫使链结构屈服位置远离链末端,从而有效抑制了滑移.研究结果对进一步认识电流变液的屈服强度,提高电流变器件的力学性能有重要参考价值.
关键词:
电流变液
滑移
极板形貌修饰
压缩应力 相似文献
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根据电流变液中球形颗粒的运动模型,研究了颗粒质量很小时,电流变液中颗粒运动的渐近状态,利用微分不等式理论,给出了相应运动的渐近估计.
关键词:
电流变液
微分不等式理论
渐近估计 相似文献
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以流动模式(flow mode)多极板之电流变阀(electrorheological valve)进行避震器阻尼力特性的研究。由于电极板的大小直接影响到流体流动的剪力及避雷器的阻尼力,因此使用多极板型式来探讨避震器的特性。设计有1-5个流道之并联及1-3个流道之串联多极板电流变阀的电流变避震器,并使用自制的电流变液进行实验。由研究结果显示,流动式并联极板之电流变避震器,一个流道之阻尼力最大,流道极板增加则阻尼力反而下降,而流动式串联多极板之电流变避震器之阻尼力则随极板数递增,故需要高阻尼力之避震器较适合使用串联多极板型式。 相似文献
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开展非等温黏弹性泊肃叶流动的光滑粒子流体动力学(SPH)方法模拟,其中流体的黏弹特性依据eXtended Pom-Pom(XPP)本构模型进行建模和计算。推导温度方程的SPH离散格式,并依据时温等效原理考量流体的黏弹特性对温度的依赖。将SPH模拟结果与利用有限体积方法得到的结果进行比较,验证SPH方法模拟非等温XPP泊肃叶流动的准确性和有效性。利用4个不同粒子初始间距进行模拟,讨论SPH方法的数值收敛性。研究温度方程的引入对泊肃叶流动带来的影响。深入分析不同物理参数对流动过程的影响。 相似文献
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The formation of density waves and the effect of wall roughness on them are studied using molecular dynamics simulations of
gravity-driven granular Poiseuille flow. Three basic types of structures are found in moderately dense flows: a plug, a sinuous
wave and a slug; a new varicose wave mode has been identified in dense flows with channels of large widths at moderate dissipations;
only clump-like structures appear in dilute flows. The simulation results are contrasted with the predictions of a linear
stability analysis of the kinetic-theory continuum equations for granular Poiseuille flow. The theoretical predictions on
the form of density waves are in qualitative agreement with simulations in denser flows, however, there are discrepancies
between simulation and theory in dilute flows. 相似文献
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Using Brownian dynamics simulations, we perform a systematic investigation of the shear-induced migration of colloidal particles subject to Poiseuille flow in both cylindrical and planar geometry. We find that adding an attractive component to the interparticle interaction enhances the migration effect, consistent with recent simulation studies of platelet suspensions. Monodisperse, bidisperse and polydisperse systems are studied over a range of shear-rates, considering both steady-states and the transient dynamics arising from the onset of flow. For bidisperse and polydisperse systems, size segregation is observed. 相似文献
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In this paper, simulation of Poiseuille flow within nanochannel containing Copper and Platinum particles has been performed using molecular dynamic (MD). In this simulation LAMMPS code is used to simulate three-dimensional Poiseuille flow. The atomic interaction is governed by the modified Lennard–Jones potential. To study the wall effects on the surface tension and density profile, we placed two solid walls, one at the bottom boundary and the other at the top boundary. For solid–liquid interactions, the modified Lennard–Jones potential function was used. Velocity profiles and distribution of temperature and density have been obtained, and agglutination of nanoparticles has been discussed. It has also shown that with more particles, less time is required for the particles to fuse or agglutinate. Also, we can conclude that the agglutination time in nanochannel with Copper particles is faster that in Platinum nanoparticles. Finally, it is demonstrated that using nanoparticles raises thermal conduction in the channel. 相似文献
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Telkki VV Zhivonitko VV 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2011,210(2):238-245
Remote detection technique can increase sensitivity of an NMR experiment by several orders of magnitude in microfluidic applications. Travel time experiment is a basic remote detection NMR experiment, which reveals the travel time distribution of the molecules flowing from the encoding coil region to the detector. In this article, we focus on analyzing how flow type (Poiseuille or plug flow), diffusion, dispersion and geometry of the flow channels are manifested in the travel time curves measured from microfluidic channels. We demonstrate that remote detection travel time experiment could be used even as an alternative NMR method for measuring self-diffusion coefficient of a fluid without magnetic field gradients. In addition, we introduce a modified travel time pulse sequence, which removes the signal of unencoded fluid spins as well as the background signal arising from the material inside or close to the detector. 相似文献
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N. N. Zholonko 《Physics of the Solid State》2006,48(9):1678-1680
The thermal conductivity of solid parahydrogen is investigated using the stationary method with a plane sample in the temperature range 1.5–6.0 K in order to reveal a Poiseuille flow in solid hydrogen. It is established that the thermal conductivity at temperatures below the low-temperature maximum decreases very rapidly in accordance with the law K ~ T n (3 < n < 8). This finding is a direct indication that the possibility exists of observing a Poiseuille flow in solid hydrogen. The results obtained are compared with those for solid helium, in which the Poiseuille flow was observed for the first time in dielectric solids. According to the estimates, the mean free path of phonons at a temperature of approximately 3 K exceeds the radius of a cylindrical sample (3 mm). The thermal conductivity in the vicinity of the low-temperature maximum is found to be two times higher than the value available in the literature. 相似文献
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This paper describes the design, computer simulation and experimental evaluation of a novel measurement system that has been recently developed for the measurement of mass flow rate of particles in a gravity chute convey pipeline. Comprehensive computer simulation and numerical calculations show that the proposed method with laser-sensing array is theoretically correct and the programmed algorithm is effective. This method has been characterized by dynamic testing, real time and continuous measurements. The results of simulation and experiment have demonstrated that the multi-laser source fan-shaped geometry can be an effective approach to interrogate the mass flow rate of particles over the pipe cross-section. The mass flow rate of particles derived from extinction principle has shown a good agreement with the projection sum of light beams and the real mass flow rate. 相似文献
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Yihao Zheng Alejandro L. Garcia Berni J. Alder 《Journal of statistical physics》2002,109(3-4):495-505
Comparison of particle (DSMC) simulation with the numerical solution of the Navier–Stokes (NS) equations for pressure-driven plane Poiseuille flow is presented and contrasted with that of the acceleration-driven Poiseuille flow. Although for the acceleration-driven case DSMC measurements are qualitatively different from the NS solution at relatively low Knudsen number, the two are in somewhat better agreement for pressure-driven flow. 相似文献
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Molecular dynamics simulations of dense and rarefied fluids comprising small chain molecules in chemically patterned nanochannels predict a novel switching from Poiseuille to plug flow along the channel. We also demonstrate behavior akin to the lotus effect for a nanodrop on a chemically patterned substrate. Our results show that one can control and exploit the behavior of fluids at the nanoscale using chemical patterning. 相似文献