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Men X.-X.,Northeastern University China | Tang C.-A.,Dalian University of Technology | Han Z.-H.,ACRE Coking And Refractory Engineering Consulting Corporation | Ma T.-H.,Dalian University of Technology
Dongbei Daxue Xuebao/Journal of Northeastern University | Year: 2013

Hydraulic fracturing process of the heterogeneity rockmass under different perforation angles was simulated using the RFPA2D2.0-Flow. Considering the heterogeneous characteristics of rock in a meso-scale, a seepage-stress-failure coupling model was created based on the finite element calculation method. The simulation results show that the maximum principal stress controls the fracture propagation direction no matter how perforation angle changes. With the increase of the perforation angle, a turning fracture becomes more obvious and the turning distance bigger. The best perforation angle area is from 0° to 30°. The numerically simulated results were in agreement with the experimental results. Source

Men X.X.,Northeastern University China | Tang C.A.,Dalian University of Technology | Han Z.H.,ACRE Coking And Refractory Engineering Consulting Corporation
Applied Mechanics and Materials | Year: 2014

Hydraulic fracturing process in fractured rockmass which with an existing single natural fracture at its various conditions: its different angles and different lengths was simulated by using RFPA2D(2.0)-Flow version which adopts the finite element method and considers the heterogeneous characteristics of rock in meso-scale, creates seepage-stress-failure coupling model. The effect tendency of natural fracture's angle and length on the seepage characteristics of fractured rockmass was given through the description of tensile fracture initiation and propagation in the rock specimens. The simulation results show that the effect of these two factors on fractures initiation, propagation and rockmass stability under the hydraulic fracturing could be remarkable. © (2014) Trans Tech Publications, Switzerland. Source

Jiang D.-Y.,ACRE Coking And Refractory Engineering Consulting Corporation | Dong H.-G.,Dalian University of Technology
AIChE Annual Meeting, Conference Proceedings | Year: 2012

A two-dimensional model, which focuses on fluid flow, heat-mass transfer, and reaction kinetics both in axial and radial directions, is developed to represent a practical reactor. And the basic model is employed to construct a state-space framework for reactor network synthesis. Total Annual Cost (TAC) as an objective is considered to describe the performance of reactor system. Source

He W.,Zhejiang University | Xu G.,Zhejiang University | Rong Z.,Shanghai Key Laboratory of Spacecraft Mechanism | Li G.,ACRE Coking And Refractory Engineering Consulting Corporation | Liu M.,Hangzhou Electric Power
Metrology and Measurement Systems | Year: 2014

Considering the low efficiency during the process of traditional calibration for digital-display vibrometers, an automatic calibration system for vibrometers based on machine vision is developed. First, an automatic vibration control system is established on the basis of a personal computer, and the output of a vibration exciter on which a digital-display vibrometer to be calibrated is installed, is automatically adjusted to vibrate at a preset vibration level and a preset frequency. Then the display of the vibrometer is captured by a digital camera and identified by means of image recognition. According to the vibration level of the exciter measured by a laser interferometer and the recognized display of the vibrometer, the properties of the vibrometer are calculated and output by the computer. Image recognition algorithms for the display of the vibrometer with a high recognition rate are presented, and the recognition for vibrating digits and alternating digits is especially analyzed in detail. Experimental results on the built-up system show that the prposed image recognition methods are very effective and the system could liberate operators from boring and intense calibration work for digital-display vibrometers. © 2014 Polish Academy of Sciences. All rights reserved. Source

Yu S.,Jilin University | Qu P.,ACRE Coking And Refractory Engineering Consulting Corporation | Liu Y.,Jilin University
Proceedings - 2014 International Conference on Mechatronics and Control, ICMC 2014 | Year: 2014

In this paper the schemes to compute robust control invariant sets for linear (uncertain) systems are collected, which are not necessary minimal robust control invariant sets. Firstly, the concept of logarithmic norm is resorted to a simply differential functional inequality. Feedback control laws are obtained for both of the two schemes. In the scheme based on the differential functional inequality, the obtained robust control invariant set is a level set of the storage function. © 2014 IEEE. Source

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