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INERTIA EFFECTS OF THE FLUID AND CYLINDER IN COAXIAL CYLINDRICAL rheometer

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Acta Mechanica Sinica 1998年第3期14卷 234-238页

作者：张建保匡震邦 Dept.of Physics The Forth Military Medical UniversityXi'an 710032China Dept.of Eng.Mechanics Shanghai Jiaotong UniversityShanghai 200240China

The inertias of the fluid and the inner cylinder in coaxial cylinder rheometer (CACR) have great influence on the unsteady flow of non-Newtonian fluid. Even for the Newtonian fluid there exist the so called stress overshoot phenomenon. This phenomenon was studied and a method correcting the measured results for an unsteady flow in the rheometer was proposed. It is found that the inertia effect of the fluid can be ignored when the gap between cylinders is small. (Edited author abstract) 11 Refs.

关键词： inertia rheometer fluid hemorheology

Autoregressive bispectrum characteristics of magneto-rheometer

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Journal of Central South University 2008年第S1期15卷 225-228页

作者：黄宜坚陈丙三蒋雨燕 College of Electro-mechanical Engineering Huaqiao University

The operating principle of measuring rheological properties of magnetorheological(MR) fluid was expounded by means of a new rheometer with double driving discs rotating at the same speed in the opposite *** constitutive equation of MR fluid was established with theoretical analysis from experimental *** conventional power spectrum approach was unable to detect the existence of quadratic phase coupling for dynamic rheological *** analysis is emerging as a new powerful technique in signal processing,which can describe nonlinear coupling,restrain Gaussian noise and reserve phase *** autoregressive(AR) model of the third order cumulant,the bispectra and bispectral contours were utilized for analyzing the dynamic characteristics of the MR rheometer by merely using the sampled output torque signals when a zero mean non-Gaussian white noise interferes with the rotary disc *** measurement and analysis process based on virtual instruments were automatically controlled by computer in this *** experimental and theoretical results show that rheological properties and dynamic characteristics of MR fluid can be measured with this double disc rheometer.

关键词： magnetorheogical fluid constitutive equation rheometer bispetrum

An analytic solution and investigation of character of viscoelastic fluids in double-gap concentric cylinder rheometer

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Science China Mathematics 1995年第12期38卷 1510-1519页

作者：黄军旗刘慈群 Department of Resources and Environmental Sciences Beijing Normal University Beijing 100875 China Institute of Porous Flow and Fluid Mechanics Chinese Academy of Sciences Langfang 102801 China

An analytical solution to annular pipe flow of the second fluid and Maxwell fluid is given using Weber integral transform. The formulas can be used to analyse the behavior of unsteady flow of viscoelastic fluid in annular pipe, especially to analyse the flow character of double-gap concentric cylinder rheometer. It is found by computation that when the outer cylinder is in simple periodic motion, there are step junctions along the history curve of Maxwell fluid’s velocity and shear stress, and at step junctions both amplitude and phase of oscillatory wave vary sharply; when the outer cylinder makes uniform rotation, the velocity and shear stress of Maxwell fluid exhibit rhombic wave oscillation, and its period is in close parabolic relation with material constant H.

关键词： viscoelastic fluid concentric cylinder rheometer analytical solution character analysis.

Development of rheometer for semi-solid high-melting point alloys

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China Foundry 2005年第4期2卷 268-274页

作者： LIU Wen XING Shu-min ZHANG Lin ZHANG Mi-lian ZHANG Hai-ying Beijing Jiaotong University Beijing 100044 P. R. China Zhengzhou Vocation Technical College Zhengzhou 450121 Henan P.R. China

A rheometer for semi-solid high-melting point alloys was developed based on the principle of a double-bucket rheometer, with which the solidifying of semi-solid high-melting point alloy melt could be effectively controlled by the control of temperature and the outer force-field; and different microstructures have also been obtained. This rheometer can be used to investigate the rheological behavior under different conditions by changing the Theological parameters. By way of full-duplex communication between the computer and each sensor, automatic control of the test equipment and real- time measurement of rheological parameters were realized. Finally, the influencing factors on torque are also quantitatively analyzed .

关键词： rheometer rheological behavior high-melting alloys semi-solid

Autoregressive bispectrum characteristics of magneto-rheometer

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Autoregressive bispectrum characteristics of magneto-rheomet...

Wall slip behavior of polymer melts on capillary rheometer

The 9th National Conference on Rheology

作者：黄宜坚陈丙三蒋雨燕 College of Electro-mechanical Engineering Huaqiao University

＜正＞The operating principle of measuring theological properties of magnetorheological（MR） fluid was expounded by means of a new rheometer with double driving discs rotating at the same speed in the opposite *** constitutive equation of MR fluid was established with theoretical analysis from experimental *** conventional power spectrum approach was unable to detect the existence of quadratic phase coupling for dynamic rheological *** analysis is emerging as a new powerful technique in signal processing,which can describe nonlinear coupling,restrain Gaussian noise and reserve phase *** autoregressive（AR） model of the third order cumulant,the bispectra and bispectrai contours were utilized for analyzing the dynamic characteristics of the MR rheometer by merely using the sampled output torque signals when a zero mean non-Gaussian white noise interferes with the rotary disc *** measurement and analysis process based on virtual instruments were automatically controlled by computer in this *** experimental and theoretical results show that rheological properties and dynamic characteristics of MR fluid can be measured with this double disc rheometer.

关键词： magnetorheogical fluid constitutive equation rheometer bispetrum

来源： cnki会议评论

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cnki会议

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Journal of Central South University 2008年第S1期15卷 98-101页

作者：廖华勇谭中欣邹国享丁永红陶国良 Polymer Materials Key Laboratory of Changzhou City Jiangsu Polytechnic University Guangzhou Institute of Energy Conversion Chinese Academy of Sciences

Wall slip behavior of three commercial polymer melts polypropylene(iPP),low-density polyethylene(LDPE)(branched chains) and high-density polyethylene(HDPE)(linear chains) were studied by using a capillary rheometer with twin bores at different *** results show that a sudden first-stick-then-slip transition was observed for HDPE and a first-slip-then-stick transition was observed for LDPE and iPP as the shear rate sweep was done in an increased order,which shows that the chain structure has an obvious effect on the wall slip behavior of *** critical shear stress for the onset of stick-slip transition increases linearly with temperature for HDPE,which accords with the disentanglement mechanism proposed by Brochard and de *** the extrapolation length used to quantify the magnitude of the transition remains about 0.05-0.09 mm for HDPE at 150-230 ℃.Also the relationship between the critical shear stress for the onset of wall slip and the molecular mass for polymer samples agrees with the disentanglement model of Brochard and de *** onset of slip-stick transition for LDPE and iPP at a critical shear stress may be interpreted as the shear thinning of the polymer chains at high shear rates,preventing further development of wall slip behavior.

关键词： polymer wall slip critical shear stress capillary rheometer temperature dependence

RHEOLOGICAL STUDIES ON REACTION INJECTION MOLDING PROCESS WITH A SLIT MEASURING SYSTEM

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Chinese Journal of Chemical Engineering 1996年第2期4卷 71-76页

作者：江体乾李春洲方波李健华东理工大学上海

A non-reacting system and a reacting system are run with an on-line slit rheometer devel-oped by the *** is found that the polyurethane-urea system behaves slightly elastic and theZaremba-Fromm-Dewitt model may be employed to describe its rheological *** the geltime,the inside pressure of the testing materials varies *** in this respect have notbeen found in literature,as yet its mechanism warrants further studies.

关键词： reacting system slit rheometer polyurethane-urea system rheological studies of RIM

RHEOLOGICAL BEHAVIOR OF POLYPHENYLENE SULFIDE/POLYAMIDE-66 BLENDS

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Chinese Journal of Polymer Science 1996年第3期14卷 225-232页

作者：侯灿淑李继红汪映寒陈永荣汪令 Institute of Materials Science and Technology Sichuan University Chengdu 610064

Blends of polyphenylene sulfide (PPS) containing trace amounts of branching and/or cross-linking in chain and Polyamide-66 (PA-66) have been prepared by melt blending. The rheological behavior of PPS/PA-66 blends has been studied by means of capillary rheometer, and compared with PPS. The effects of shear rate, shear stress and temperature on the how of PPS/PA-66 blends and PPS are discussed. The non-Newtonian indexes and the activation energies of viscous how are obtained. The results show that the apparent viscosity of PPS/PA-66 blends is not sensitive to shear rate and stress, but decreases with the elevation of temperature. On the contrary, the apparent viscosity of the PPS decreases obviously with the increasing of shear rate and shear stress, but it is increased by the elevation of temperature.

关键词： polyphenylene sulfide polyamide-66 polyphenylene sulfide polyamide-66 blends rheological behavior rheometer

Experiments and analysis for rheological properties of MRF

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Journal of Central South University 2008年第S1期15卷 284-287页

作者：王海霞阮予明孔笋王捷 Fujian Electric Vocational and Technical College Department of Mechanical and Electric Engineering

The work principle of flat-plate structure under shearing mode is expounded based on a vertical type rheometer for MRF which combined data acquisition with treatment and result *** formula to calculate shearing stress is *** on different recipe for MRF,experiments under different working gap length were done by altering the intensity of magnetic *** rheological model for MRF was established and the relationships between shearing stress,viscosity and magnetic field intensity were *** indicate that MRF has the flowing characters:with an increase of the magnetic induction and the nominal shear rate,the shear stress of MRF ***,as the working gap decreases,the shear stress *** has shear thinning property under magnetic field.

关键词： magneto-rheological fluid constitutive equation rheometer experiment