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Experimental Studies on Swirling Gas-Particle Flows in a Spouting-Cyclone Combustor

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Journal of Thermal Science 1992年第3期1卷 203-207页

作者： l.x.zhou B.zhou 等 DepartmentofEngineeringMechanics TsinghusUniversityBeijing100084China DepartmentofEngineeringMechan

The gas and particle time-averaged velocity rand RMS fluctuation velocity of swirling gas-particle flows in a spouting-cyclone combustor were measured by a hot-ball probe and a conventional lDV system. The results show large velocity slip between the two phases both in tangential and axial directions and high nonisotropic turbulence of the two phases were also observed which is favorable to coal combustion. The particle RMS fluctuation velocity is higher than the gas RMS fluctuation velocity only in some regions of the flow field.

关键词： gas-particle flows swirling flows cyclone combustor lDV measurements.

A　k－ε－PDF　Two－Phase　Turbulence　Model　for　Simulating　Sudden－Expansion　Particle－laden　Flows

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Journal of Thermal Science 1996年第1期5卷 34-38页

作者： Y.li l.x.zhou DepartmentofEngineeringMechanics TsinghuaUniversityBeijingChina DepartmentofEngineeringMechanics Ts

A k - ε-PDF model based on statistical theory for turbulent gas-particle flows is proposed,and a numerical procedure combining the finite difference and finite fluctuating-velocity -group methods is *** obtained statistically averaged equations have the same form as those obtained by using the Reynolds *** the k -ε-PDF model (PDF particle turbulence model combined with the k - ε gas turbulence model),many terms,such as the diffusion term in particle Reynolds Stress equations,can be accurately calculated for verifying the second-moment-closure *** k - ε- PDF model is used to simulate sudden-expansion particle-laded *** of the predictions using both k -ε-PDF and the k - ε- kp models with experimental results shows that the k - ε-PDF model give more reasonable non-isotropic features of particle turbulence.

关键词： turbulent gas-particle flows statistical theory turbulence models nonisotropic turbulence.

Experiment of Cooling-film Flows in a Hot-fire Environment

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Experiment of Cooling-film Flows in a Hot-fire Environment

Viscosity and structure relationship with equimolar substitution of CaO with MgO in the CaO–MgO–Al_(2)O_(3)–SiO_(2)slag melts

第六届国际流体力学会议

作者： M.Q.Zhang 1 G.H.Yang 2 l.x.zhou 2 l.Hong 2 Z.l.Zhang 2 1 Northwestern Polytechnical University xi’an 710072 China 2 xi’an Aerospace Propulsion Institute xi’an 710100 China

Experimental and numerical investigations on a cooling liquid-film flow in a hot-fire environment within a model combustion chamber were carried out to characterize the flow and heat transfer phenomena and to provide insight into flowfield and guide the evolution of the cooling design.A model combustion chamber with optical windows was set up for shadowgraph imaging of the liquid *** simulations using a separate-phase VOF method of the liquid-film flow and the combustion of the gaseous oxygen and methane were conducted to characterize the cooling-film flow and heat transfer between the hot combustion products and the liquid film.

关键词： film-cooling liquid rocket engine numerical simulation optical diagnostics gas-liquid interface

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cnki会议

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 70-79页

作者： Yong Hou Shuo Zhang Jie Dang Jia Guo Hanghang zhou xuewei lü College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Chongqing Key laboratory of Vanadium-Titanium Metallurgy and New Materials Chongqing UniversityChongqing 400044China

Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this *** most studies that concentrated on managing the MgO/Al_(2)O_(3)ratio or basicity,this paper explored the effect of equimolar substitution of MgO for CaO on the viscosity and structure of a high-alumina CaO-MgO-Al_(2)O_(3)-SiO_(2)slag system,providing theoretical guidance and data to facilitate the application of high-alumina *** results revealed that the viscosity first decreased and then increased with higher MgO substitution,reaching a minimum at 15mol%MgO *** transform infrared spectroscopy(FTIR)results found that the depths of the troughs representing[SiO_(4)]tetrahedra,[AlO_(4)]tetrahedra,and Si-O-Al bending became progressively deeper with increased MgO *** of the Raman spectra showed that the average number of bridging oxygens per Si atom and the x_(Q^(3))/x_(Q^(2))(x_(Q^(i))is the molar fraction of Q^(i) unit,and i is the number of bridging oxygens in a[SiO_(4)]tetrahedral unit)ratio increased from 2.30 and 1.02 to 2.52 and 2.14,respectively,indicating a progressive polymerization of the silicate structure.x-ray photoelectron spectroscopy(xPS)results highlighted that non-bridging oxygen content decreased from 77.97mol% to 63.41mol% with increasing MgO concentration,whereas bridging oxygen and free oxygen contents *** analysis demonstrated a gradual increase in the polymerization degree of the tetrahedral structure with the increase in MgO ***,bond strength is another important factor affecting the slag *** occurrence of a viscosity minimum can be attributed to the complex evolution of bond strengths of non-bridging oxygens generated during depolymerization of the[SiO_(4)]and[AlO_(4)]tetrahedral structures by CaO and MgO.

关键词： aluminosilicate viscosity structure spectroscopy

Fluid-structure interaction in Z-shaped pipe with different supports

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Acta Mechanica Sinica 2020年第2期36卷 513-523页

作者： Q.Guo J.x.zhou x.l.Guan College of Water Conservancy and Hydropower Engineering Hohai UniversityNanjing 210098China Highway Science and Technology Research Institute Xinjiang Production and Construction Corpsürümqi 830002China

Fluid-structure interaction(FSI)has a strong relation with layout of fluid delivery *** is liable to cause local ***,FSI analysis is necessary in many cases,especially for flexible pipe *** modeling consists of eight governing equations and then completely solved via the finite volume method(FVM).Friction,Poisson and joint couplings were discussed in detail to reveal the influence of a Z-shaped pipe with different supports and elbows on *** the feasibility of solving FSI by FVM was verified,the different effects of free,fixed and elastic supports on FSI in the commonly used and simplified Z-shaped pipe were further *** indicated that different support stiffness lead to various FSI *** coupling occurs at the elbow and less support is considered,then the pipe has a relatively large amplitude and complex pressure fluctuation.

关键词： Fluid-structure interaction Finite volume method Z-shaped pipe Support stiffness

A SIMUlATION STUDY OF DEPOSITION UNDER TWO TYPES OF IMPINGING TRAJECTORIES

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维普期刊数据库

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Acta Metallurgica Sinica(English letters) 2004年第6期17卷 876-880页

作者： x.Q.Wei l.zhou SchoolofMaterialsScience＆Engineering NanchangUniversityNanchang330047China

A model coupling particle aggregation and randomwalk surface diffusion has been developed for 2D simulation of depositional growth, in which impinging particles follow either a straight-line trajectory of cosine distribution, representing typically sputter deposition, or a scattered trajectory, representing typically electrochemical deposition. Simulations of the growth under various impinging conditions and effective surface diffusivity have been carried out. Pattern and defect development in deposition on flat, trenched and ridged substrates have been investigated. We found that on flat and ridged substrates, both types of trajectories yield similar features, including formation of cone-like defects on surface ridges. While on trenched substrate, the straight-line impingement yielded more uniform step coverage than the scattered impingement.

关键词： deposition simulation pattern formation ballistic model

Polyethylene glycol has immunoprotective effects on sciatic allografts, but behavioral recovery and graft tolerance require neurorrhaphy and axonal fusion

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Neural Regeneration Research 2025年第4期20卷 1192-1206页

作者： Tyler A.Smith liwen zhou Cameron l.Ghergherehchi Michelle Mikesh Cathy Z.Yang Haley O.Tucker JuliAnne Allgood Jared S.Bushman George D.Bittner Department of Molecular Biosciences University of Texas at AustinAustinTXUSA Department of Neuroscience University of Texas at AustinAustinTXUSA Division of Pharmaceutical Sciences University of WyomingLaramieWYUSA

Behavioral recovery using(viable)peripheral nerve allografts to repair ablation-type(segmental-loss)peripheral nerve injuries is delayed or poor due to slow and inaccurate axonal ***,such peripheral nerve allografts undergo immunological rejection by the host immune *** contrast,peripheral nerve injuries repaired by polyethylene glycol fusion of peripheral nerve allografts exhibit excellent behavioral recovery within weeks,reduced immune responses,and many axons do not undergo Wallerian *** relative contribution of neurorrhaphy and polyethylene glycol-fusion of axons versus the effects of polyethylene glycol per se was unknown prior to this *** hypothesized that polyethylene glycol might have some immune-protective effects,but polyethylene glycol-fusion was necessary to prevent Wallerian degeneration and functional/behavioral *** examined how polyethylene glycol solutions per se affect functional and behavioral recovery and peripheral nerve allograft morphological and immunological responses in the absence of polyethylene glycol-induced axonal ***-type sciatic nerve injuries in outbred Sprague–Dawley rats were repaired according to a modified protocol using the same solutions as polyethylene glycol-fused peripheral nerve allografts,but peripheral nerve allografts were loose-sutured(loose-sutured polyethylene glycol)with an intentional gap of 1–2 mm to prevent fusion by polyethylene glycol of peripheral nerve allograft axons with host *** to negative control peripheral nerve allografts not treated by polyethylene glycol and in contrast to polyethylene glycol-fused peripheral nerve allografts,animals with loose-sutured polyethylene glycol peripheral nerve allografts exhibited Wallerian degeneration for all axons and myelin degeneration by 7 days postoperatively and did not recover sciatic-mediated behavioral functions by 42 days *** morphological signs of rejection,such as col

关键词： allograft rejection axotomy macrophage myelin nerve repair polyethylene glycol(PEG) sciatic nerve T cell transplantation Wallerian degeneration

Controlled cationic ring-opening polymerization of l-lactide by organic ion pair: novel approach to isotactic-rich and crystalline polylactide

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Science China Chemistry 2025年第1期 394-402页

作者： Zhiqiang Ding Mingqian Wang Zijing zhou Bin Wang Yuesheng li Tianjin Key laboratory of Composite & Functional Materials School of Materials Science and Engineering Tianjin University

living/controlled cationic ring-opening polymerization （ROP） of l-lactide is a promising approach to isotactic-rich and crystalline poly（l-lactide）.In contrast with the unsubstituted lactones,l-lA can not be polymerized by organic lewis acids or carbenium ions,and the state of the art in this field is the cationic ROP of l-lA catalyzed by Br?nsted acid/alcohol system via activated monomer ***,we reported the first example of controlled cationic ROP of l-lA by using Meerweintype ion pair[Me3O]+[B（C6F5）4]-as the catalyst.[Me3O]+[B（C6F5）4]-promoted rapid l-lA cationic polymerization in the absence of alcohol,producing isotactic-rich and crystalline PllA without transesterification and epimerization side *** activated chain end mechanism,involving twice SN2 substitution and configuration-inversion （S→R→S） with the assistance of released Me2O,was proposed and further verified by density functional theory and control *** work expands the catalytic toolbox of isotactic-rich and crystalline polylactide *** represents a unique example of cationic-controlled polymerization of l-lA catalyzed by an organic ion pair.

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Structure evolution of the Fe_(3)C/Fe interface mediated by cementite decomposition in cold-deformed pearlitic steel wires

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Journal of Materials Science & Technology 2022年第6期101卷 28-36页

作者： Y.T.zhou x.H.Shao S.J.Zheng x.l.Ma Shenyang National laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Tianjin Key laboratory of Materials laminating Fabrication and Interface Control Technology School of Materials Science and EngineeringHebei University of TechnologyTianjin 300130China

Cold-drawn pearlitic steel wire is irreplaceably used in industry owing to its outstanding mechanical property which is dominated by the cementite/ferrite(Fe_(3)C/Fe) interfaces in the material. However, the fine structures of the Fe3C/Fe interfaces in the deformed wires are less known to date. In this work, transmission electron microscopic investigation was performed on the atomic structures of the interfaces with the Isaichev orientation relationship(OR) in the wires with progressive deformation strains. In addition to the effect of the dislocation/interface interactions, this work revealed that the deformation-induced partial decomposition of cementite plays an important role in the interface reconstruction during deformation. The interfacial carbon vacancies generated by cementite decomposition and particularly, the amorphization of cementite layers in the sample with ε > 1 could effectively annihilated the interfacial dislocations and consequently relaxed the interfacial stress. The correlations between the interface structure changes and the mechanical properties of the wires were discussed.

关键词： Pearlitic steel Cementite decomposition Interface structure Deformation Transmission electron microscopy