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含空洞复杂岩体 1

微震事件定位 1

快速行进法 1

龙格-库塔法 1

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Kinetic model for hydroisomerization reaction of C-aromatics

XU Ouguan, SU Hongye, JIN Xiaoming, CHU Jian

《化学科学与工程前沿（英文）》 2008年第2卷第1期页码 10-16 doi: 10.1007/s11705-008-0015-2

摘要： Based on the reported reaction networks, a novel six-component hydroisomerization reaction network with a new lumped species including C-naphthenes and C-paraffins is proposed and a kinetic model for a commercial unit is also developed. An empirical catalyst deactivation function is incorporated into the model accounting for the loss in activity because of coke formation on the catalyst surface during the long-term operation. The Runge-Kutta method is used to solve the ordinary differential equations of the model. The reaction kinetic parameters are benchmarked with several sets of balanced plant data and estimated by the differential variable metric optimization method (BFGS). The kinetic model is validated by an industrial unit with sets of plant data under different operating conditions and simulation results show a good agreement between the model predictions and the plant observations.

关键词： ordinary differential Runge-Kutta catalyst deactivation C-paraffins optimization

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Dynamics analysis of a cracked dual-disk over-hung rotor-bearing system

CHEN Hong, LI He, WEN Bang-chun, ZHANG Xiao-wei

《机械工程前沿（英文）》 2006年第1卷第2期页码 204-208 doi: 10.1007/s11465-006-0002-6

摘要： A dynamic model of a dual-disk vertical over-hung rotor-bearing system is developed, taking into account nonlinear oil-film force. Its dynamic behaviors are investigated by numerical Runge-Kutta method. Its bifurcation and chaos characteristics are analyzed with crack fault and without crack fault. By analyzing the bifurcation plot, Poincare section plots and amplitude spectra, we found that the crack greatly influences the dynamic characteristics of the rotor-bearing system. Because of the strong effect of the nonlinear oil-film force and crack to the system, 1/2 times, 1/3 times frequency components appear in the response spectrum map. The results may bring up theoretical references for fault diagnosis of rotor-bearing systems.

关键词： nonlinear oil-film diagnosis bifurcation dynamic numerical Runge-Kutta

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Chaotic behavior of LNG after stratification in main stream region of storage tank

WANG Jingjing, MA Xiaoqian

《能源前沿（英文）》 2008年第2卷第4期页码 514-518 doi: 10.1007/s11708-008-0076-4

摘要： A study of the chaotic behavior of liquefied natural gas (LNG) after stratification in the main stream region of a storage tank was conducted. Based on non-linear dynamics, a 2-dimensional Rayleigh-Benard convection model was developed to simulate the convection, Lorenz equations of LNG convection were deduced from conservation equations, and the Runge-Kutta method was used to solve the equations. The results showed that when = 1.33, 106 < < 1470, chaos was obtained, which meant that the velocity field and the temperature field were highly unsteady. In addition, the influence of temperature and scale factor on the solutions and the corresponding range of parameters were studied. The results revealed that the chaos in LNG convection resulted from the interaction of buoyancy and viscid forces. A small quantity of heat impacting the storage tank would lead to a strong and unstable convection of LNG in the main stream region.

关键词： Runge-Kutta non-linear corresponding temperature addition

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含空洞岩体微震定位的快速行进法——性能分析与工程应用 Article

蒋若辰, 戴峰, 刘燚, 李昂

《工程（英文）》 2021年第7卷第7期页码 1023-1034 doi: 10.1016/j.eng.2020.10.019

摘要：

微震事件定位是微震监测技术的重要组成部分，用于圈定围岩损伤区。然而，复杂的地质条件会对最终的微震事件定位结果造成不利的影响。为实现含空洞复杂岩体中的高精度微震事件定位，本研究基于二阶差分形式的快速行进法，开发了微震事件定位方法。该方法基于建立的三维离散网格波速模型，通过搜索满足理论到时与实际到时之间残差最小的网格节点，实现对微震事件的定位。此外，基于二阶快速行进法的计算结果，微震破裂源到微震传感器的传播路径，可通过应用线性插值与龙格-库塔法获得。所用方法的合理性在一系列的数值仿真实验中得到了验证。提出的方法被应用于定位在猴子岩水电站地下洞室开挖过程中所记录的爆破与微震事件。爆破事件的定位结果表明，与采用均一岩体波速模型的定位结果相比，本方法能够有效减低微震事件定位误差。而对于微震事件的定位结果，通过现场的混凝土破裂与剥落，以及现场多点位移计的监测结果得到验证。本文提出的方法可提供相对更准确的岩体破裂位置，为圈定围岩损伤区工作提供便利。

关键词：快速行进法微震事件定位含空洞复杂岩体龙格-库塔法