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Investigation of high rate mechanical flow followed by ignition for high-energy propellant under dynamic extrusion loading

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Defence Technology（防务技术） 2024年第2期32卷 336-347页

作者： Liying Dong Yanqing Wu Kun Yang xiao hou State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China

Investigating the ignition response of nitrate ester plasticized polyether(NEPE) propellant under dynamic extrusion loading is of great significant at least for two cases. Firstly, it helps to understand the mechanism and conditions of unwanted ignition inside charged propellant under accident ***, evaluates the risk of a shell crevice in a solid rocket motor(SRM) under a falling or overturning scene. In the present study, an innovative visual crevice extrusion experiment is designed using a dropweight apparatus. The dynamic responses of NEPE propellant during extrusion loading, including compaction and compression, rapid shear flow into the crevice, stress concentration, and ignition reaction, have been firstly observed using a high-performance high-speed camera. The ignition reaction is observed in the triangular region of the NEPE propellant sample above the crevice when the drop weight velocity was 1.90 m/s. Based on the user material subroutine interface UMAT provided by finite element software LS-DYNA, a viscoelastic-plastic model and dual ignition criterion related to plastic shear dissipation are developed and applied to the local ignition response analysis under crevice extrusion conditions. The stress concentration occurs in the crevice location of the propellant sample, the shear stress is relatively large, the effective plastic work is relatively large, and the ignition reaction is easy to occur. When the sample thickness decreases from 5 mm to 2.5 mm, the shear stress increases from 22.3 MPa to 28.6 MPa, the critical value of effective plastic work required for ignition is shortened from 1280 μs to 730 μs, and the triangular area is easily triggering an ignition reaction. The propellant sample with a small thickness is more likely to stress concentration, resulting in large shear stress and effective work, triggering an ignition reaction.

关键词： NEPE propellant Crevice extrusion Shear flow Sample thickness Ignition reaction

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Radiative properties of alumina/aluminum particles and influence on radiative heat transfer in solid rocket motor

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Chinese Journal of Aeronautics 2022年第2期35卷 98-116页

作者： Xuefan HAO Hu ZHANG xiao hou Guihua TANG State Key Laboratory for Strength and Vibration of Mechanical Structures Xi’an Jiaotong UniversityXi’an 710049China Shaanxi Key Laboratory of Environment and Control for Flight Vehicle Xi'an Jiaotong UniversityXi’an 710049China College of Astronautics Northwestern Polytechnical UniversityXi’an 710072China Key Laboratory of Thermo-Fluid Science and Engineering Ministry of EducationXi’an Jiaotong UniversityXi’an 710049China

The thermal radiation of micron-sized condensed phase particles plays a dominant role during the heat transfer process in aluminized Solid Rocket Motors(SRMs).Open research mainly focuses on the radiative properties of alumina particles while the study considering the presence of aluminum is *** addition,the thermal radiation inside the SRM with consideration of the participating particles is seldom *** this work,the multiscale method of predicting the thermal environment inside SRMs is established from the particle radiation at microscale to the twophase flow and heat transfer at *** effective gray radiative properties of individual particles(alumina,aluminum,and hybrid alumina/aluminum)and particles cloud are investigated with the Mie theory and approximate *** a numerical method for predicting the thermal environment inside SRMs with considering particle radiation is established and applied in a subscale *** convective and radiative heat flux distributions along inner wall of motor are obtained,and it is found that the heat transfer in the combustion chamber is dominated by thermal radiation and the radiative heat flux is essentially a constant of 5.6–6.8 MW/m^(2).The convective heat transfer plays a dominant role in the nozzle and the heat flux reaches the maximum value of 11.2 MW/m^(2) near the *** the combustion efficiency of aluminum drops,the radiative heat flux remains unchanged in most regions and increases slightly along the diverging section wall of the nozzle.

关键词： Alumina Aluminum Condensed phase particle Radiative heat transfer Radiative properties Solid rocket motor

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Vertical-horizontal coupling nonlinear vibration characteristics of rolling mill under mixed lubrication

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Journal of Iron and Steel Research International 2021年第5期28卷 574-585页

作者： Dong-xiao hou Liang Xu Pei-ming Shi School of Control Engineering Northeastern University at QinhuangdaoQinhuangdao 066004HebeiChina School of Electrical Engineering Yanshan UniversityQinhuangdao 066004HebeiChina

Considering the dynamic influence of the roll vibration on the lubricant film thickness in the rolling deformation area,nonlinear dynamic rolling forces related to film thickness in the vertical and horizontal directions were obtained based on the Karman balance *** on these dynamic rolling forces and the mechanical vibration of the rolling mill,a vertical-horizontal coupling nonlinear vibration dynamic model was *** amplitude-frequency equation of the main resonance was derived by using the multiple-scale *** last,the parameters of the 1780 rolling mill were used for numerical simulation,and the time-domain response curves of the system’s vibration displacement and lubricating film thickness under the steady and unsteady conditions were *** influences of parameters such as interface contact ratio,nonlinear parameters and external disturbances on the primary resonance frequency characteristics were obtained,which provided a theoretical reference for the suppression of rolling mill vibration.

关键词： Vertical-horizontal coupling Nonlinear vibration Mixed lubrication Dynamic rolling force Main resonance Amplitude-frequency characteristic

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Contribution of redox-active properties of compost-derived humic substances in hematite bioreduction

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Chinese Chemical Letters 2022年第5期33卷 2731-2735页

作者： Chao Yang Lin-xiao hou Bei-Dou Xi Li-An hou xiao-Song He State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental SciencesBeijing 100012China State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution Chinese Research Academy of Environmental SciencesBeijing 100012China School of Environmental Science and Engineering Tianjin UniversityTianjin 300350China College of Chemical and Biological Engineering Zhejiang UniversityHangzhou 310027China High-Tech Institute of Beijing Beijing 710025China

The compost-derived humic substances(HS)can function as electron mediators for promoting hematite bioreduction because of its redox *** process can affect redox capacities of compost-derived HS by changing its intrinsic ***,the redox properties of compost-derived HS link-ing with hematite bioreduction during composting still remain ***,we investigated the redox capacities of compost-derived HS,and assessed the responses of the redox capacities to the hematite *** result showed that compost-derived HS(i.e.,humic acids(HA)and fulvic acids(FA))were able to accept electrons from Shewanella oneidensis MR-1,and the electron accepting capacity was increased during ***,it could be functioned as electron mediators for promoting the hematite bioreduction,achieving 1.19-2.15 times compared with the control *** only the aromatic structures(quinone)but also the non-quinone structures such as nitrogen-and sulfur-containing functional moieties were served as the redox-active functional groups of compost-derived *** work proved that the aromatic functional groups and the heteroatom structures(especially N)were important to the hematite *** study highlights the redox-active properties of compost-derived HS and its impact on the microbial reduction of iron *** capacity of compost-derived HS might mitigate the environmental risk of contaminants when the composting production was added into the contaminated soils as low-cost repair materials.

关键词： Composting Humic substances Reducing capacities Humic acids Hematite bioreduction

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Interaction between a Dark Septate Endophytic Isolate from Dendrobium sp. and Roots of D. nobile Seedlings

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Journal of Integrative Plant Biology 2009年第4期51卷 374-381页

作者： xiao-Qiang hou Shun-Xing Guo Institute of Medicinal Plant Development the Chinese Academy of Medical Sciences and Peking Union Medical College Beijing 100094 China

Interactions between an isolate of dark septate endophytes （DSE） and roots of Dendrobium nobile Lindl. seedlings are reported in this paper. The isolate was obtained from orchid mycorrhizas on Dendrobium sp. in subtropical forest. The fungus formed typical orchid mycorrhiza in aseptic co-culture with D. nobile seedlings on modified Murashige-Skoog （MMS） medium. Anatomic observations of the infected roots showed that the DSE hyphae invaded the velamen layer, passed through passage cells in exodermis, entered the cortex cells, and then formed fungal pelotons of orchid mycorrhiza. D. nobile seedlings＇ plant height, stem diameter, new roots number and biomass were greatly enhanced by inoculating the fungus to seedlings. The fungus was identified as Leptodontidium by sequencing the polymerase chain reaction-amplified rDNA ITS1-5,8S-ITS2 （internal transcribed spacer （ITS）） regions and comparison with similar taxa.

关键词： dark septate endophytes Dendrobium nobile fugal inoculation intemal transcribed spacer molecular identification archid mycorrhiza plant growth.

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A Family of Adaptive H_∞ Controllers with Full Information for Dissipative Hamiltonian Systems

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International Journal of Automation and computing 2011年第2期8卷 209-214页

作者： Song Xu xiao-Rong hou School of Automation Engineering University of Electronic Science and Technology of China Chengdu 611731 PRC Faculty of Science Ningbo University Ningbo 315211 PRC

This paper investigates a parameterization method of adaptive H∞ controllers for dissipative Hamiltonian systems with disturbances and unknown *** family of adaptive H∞ controllers with full information is obtained by interconnecting an adaptive H∞ controller with a generalized zero-energy-gradient （ZEG） detectable,free generalized Hamiltonian *** present parameterization method avoids solving Hamilton-Jacobi-Issacs equations and thus the controllers obtained are easier in operation as compared to some existing *** show the effectiveness and feasibility of the adaptive control strategy proposed in this paper.

关键词： Parameterization adaptive H∞ controller dissipative Hamiltonian system full information generalized zero-energygradient (ZEG) detectable.

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A temperature/strain-rate-dependent finite deformation constitutive and failure model for solid propellants

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Science China(Physics,Mechanics & Astronomy) 2023年第9期66卷 63-78页

作者： Ming Lei Erhao Chen Zeang Zhao Lihua Wen Jinyou xiao xiao hou School of Astronautics Northwestern Polytechnical UniversityXi’an 710072China Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China China Aerospace Science and Technology Corporation Beijing 100048China

The stress-strain response under progressive damage and the ultimate failure of solid propellants are two key issues affecting the integrity of solid rocket *** research primarily focused on the progressive damage in solid propellants during production and ***,they failed to take the temperature/strain-rate-dependent ultimate failures into *** failure strains of solid propellants are experimentally observed to show strong temperature/strain-rate dependence and exhibit an abnormal evolution at low and high temperatures,*** increasing loading strain rate,the failure strains decrease at low temperatures near the glass transition temperature(T_g)but increase at high temperatures far above T_(g).In this study,we introduce the glassy and rubbery failure criteria based on strain energy densities at ultralow and ultrahigh temperatures,respectively,into a viscoelastic constitutive model and build a unified model for the progressive damage and the ultimate failure of solid *** the introduction of these two additional criterion parameters,the developed model can effectively predict the yield-type stress-strain responses,microscopic damage-induced volume dilatations,and temperature/strain-ratedependent ultimate failures of the solid propellants by comparing the model predictions with the experimental *** competition between the glassy failure and the rubbery failure results in the propellants exhibiting a maximum break strain near the glass transition ***,when the strain rate is increased,the propellants exhibit a predominantly glassy response,which shifts the failure envelope toward a higher *** induces an abnormal evolution of failure strains by making the propellants stretchable at high temperatures and brittle at low temperatures.

关键词： viscoelastic material polymeric material constitutive behavior fracture toughness failure envelope

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Inherent relationship between process parameters,crystallization and mechanical properties of continuous carbon fiber reinforced PEEK composites

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Defence Technology（防务技术） 2023年第6期24卷 269-284页

作者： xiao-long Ma Li-hua Wen Shi-yu Wang Jin-you xiao Wen-hao Li xiao hou School of Astronautics Northwestern Polytechnical UniversityXi'an710072China China Aerospace Science and Technology Corporation Beijing100048China

High-performance thermoplastic composites have been developed as significant structural materials for cutting-edge equipment in the aerospace and defence ***,the internal mechanism of processing parameters on mechanical properties in the manufacturing process of thermoplastic composite structures is still a serious *** purpose of this study is to investigate the process/crystallization/property relationships for continuous carbon fiber(CF)reinforced polyether-ether-ketone(PEEK)*** composite laminates are fabricated according to orthogonal experiments via the thermoforming *** mechanical performance is investigated in terms of crystallization properties and fracture morphology *** results show that the mechanical performance and crystallization properties of thermoplastic composites are significantly affected by the coupling of processing *** increased molding temperature,pressure,and holding time improve the degree of fiber/matrix infiltration and affect the crystallinity and crystalline morphology of the matrix,which further influences the mechanical properties of the *** is reflected in the test results that crystallinity has an approximately linear effect on mode-I interlaminar fracture toughness and transverse flexural *** well as the higher molding temperature can destroy the pre-existent crystals to improve the toughness of the matrix,and the well-defined crystalline structures can be observed when fabricated at higher temperatures and longer periods of holding time.

关键词： Polymer matrix composites Thermoplastic Processing parameters Mechanical properties Crystallization

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Vibration characteristics of multi-parametric excitations and multi-frequency external excitations of rolling mill under entry thickness fuctuation of strip

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Journal of Iron and Steel Research International 2020年第5期27卷 517-527页

作者： Teng Xu Dong-xiao hou Zheng-nan Sun Da-wu Guo School of Control Engineering Northeastern University at QinhuangdaoQinhuangdao 066004HebeiChina

A dynamic rolling force model with multi-parametric excitations and multi-frequency external excitations caused by entry thickness fuctuation of strip was *** on the dynamic rolling force,a nonlinear vertical vibration model with multi-parametric excitations and multi-frequency external excitations was *** method of multiple scales was used to solve the amplitude-frequency characteristic equation of primary resonance of the nonlinear vibration system of a rolling *** transition set and the topology structure of systematic global bifurcation were obtained by using the singularity ***,primary resonance characteristics of the system under entry thickness fuctuation of strip were analyzed by using actual parameters of the rolling *** global bifurcation curves with the change of amplitude and frequency of entry thickness fuctuation of strip were obtained by using numerical simulation,and many dynamic behaviors were found such as single-cycle motion,multi-cycle motion and chaotic motion,which can provide a theoretical reference for further restraining the vibration of a rolling mill.

关键词： Entry thickness fluctuation Dynamic rolling force Nonlinear vertical vibration Primary resonance Bifurcation

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LATTICE BGK MODEL SIMULATION OF ASYMMETRIC FLOW INSIDE A CONTINUOUS SLAB CASTING MOLD

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Journal of Hydrodynamics 2006年第4期18卷 431-435页

作者： ZHANG xiao-jun SHEN hou-fa Key Laboratory for Advanced Manufacturing by Materials Processing Technology Department of Mechanical Engineering Tsinghua University Beijing 100084 China

The incompressible lattice Bhatnager-Gross-Krook （BGK） model of computational fluid dynamics, from which the unsteady incompressible Navier-Stokes equations can be exactly derived with the limit of small Mach number, was established in continuous casting mold. An asymmetric flow pattern in the two-dimensional central plane of continuous slab casting mold was simulated, and the flow pattern is not stationary but changes over frequently if the Reynolds number is larger than 3000 or so. The results are found to be in excellent agreement with previous experimental results.

关键词： lattice Bhatnager-Gross-Krook (BGK) method incompressible Navier-Stokes equation continuous slab casting mold

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