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基于流固耦合理论,采用数值模拟的方法,研究油田常用的120°放喷弯头和90°放喷弯头在流场作用下的变形和应力情况,经对比得到120°弯头的最大应力和最大等效应力均小于90°弯头。然后通过输入参数(压强、壁厚、流速)对输出参数(放喷弯头的变形和应力)的敏感性分析,结果表明:压强与放喷弯头的最大变形和最大等效应力之间呈现强的正相关性;壁厚则与两者呈现较强的负相关性;相比之下,流速的影响并不明显。这样在进行弯头的优化设计时,有助于参数之间的取舍。 相似文献
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复合材料螺旋桨性能研究的重要方法之一是流固耦合分析方法,求解流固耦合方程能够获得复合材料螺旋桨的水动力性能与结构响应。通过对国内外复合材料螺旋桨流固耦合分析方法的总结和归纳,分别介绍了主流的流固耦合分析方法——VLM/FEM流固耦合方法、BEM/FEM流固耦合方法和CFD/FEM流固耦合方法,同时对其研究内容和发展现状进行了简单阐述,展望了未来复合材料螺旋桨流固耦合分析方法研究趋势,为进一步研究复合材料螺旋桨流固耦合方法提供了参考。 相似文献
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管道内液体流动参数随时间变化引起的管道振动,会导致管道共振、连接失效或断裂,对管路系统的稳定和安全运行产生巨大的危害.本文基于泊松流固耦合原理,建立流体动力学模型和管道运动模型,进行流固耦合受力分析和模态分析,研究了有无流固耦合存在时,输流管道振动模态的变化,以及入口速度、压强和壁厚对管道固有频率和阵型的影响.结果显示... 相似文献
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压力管道系统中存在流体和结构之间的耦合,对压力管道的流固耦合现象进行分析,建立了流固耦合的有限元数学模型,运用有限元软件ansys模拟流体介质通过管道弯头,对压力管道弯头在不同约束条件下的流固耦合现象进行了数值模拟计算,并进行了压力,温度,流线型分析等.计算结果表明流固耦台作用对压力管道系统的运行有重大影响,验证了压力... 相似文献
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压力管道系统中存在流体和结构之间的耦合。对压力管道的流固耦合现象进行分析,建立了流固耦合的有限元数学模型,运用有限元软件ansys模拟流体介质通过管道弯头,对压力管道弯头在不同约束条件下的流固耦合现象进行了数值模拟计算,并进行了压力,温度,流线型分析等。计算结果表明流固耦合作用对压力管道系统的运行有重大影响,验证了压力管道考虑流体介质、速度、压力的影响,并为特种设备的制造提供了设计方向和重点检验方向。 相似文献
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换热器流固传热边界数值模拟温度场的顺序耦合方法 总被引:4,自引:0,他引:4
通过建立由壳体、管板和换热管等组成的换热器有限元分析模型,使用FLUENT生成的CDB文件和ANSYS本身的物理场进行耦合,把外部CBD边界条件映射到ANSYS模型上。先利用"分段建模,整体综合"技术,从实现换热器的工艺热分析的角度考虑,由FLUENT软件得到换热器整体温度场,输出得到了包含固体表面节点、单元和温度载荷等信息的CDB文件,然后利用温度场顺序耦合的思想,利用由FLUENT得到的结构温度场边界,在ANSYS软件中取节点文件并求解,创建结构热分析所需的结构温度场。比对CFD结果和有限元结果可知,两者温度场的分布没有差别,此耦合过程中没有出现失真现象,这为研究换热器的温差应力分析提供了可靠的依据。 相似文献
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铝钛复合偶联剂及其在高聚物中的应用 总被引:3,自引:0,他引:3
异丙醇分别与铝和四氯化钛反应,再加入硬脂酸进行酯交换反应,二者所得产物继续反应可制备熔点为45 ̄65℃,金属原子质量分数为4.50% ̄4.90%的铝钛复合偶联剂。实验结果表明,在生产力车内胎时,用各50份的铝钛复合偶联剂活化的CaCO3、普通轻质CaCO3和其他偶联剂活化的CaCO3分别补强50份的NR,补强性能以前者为佳。且采用铝钛复合偶联剂活化的CaCO3后可增加无机物的填充量,降低制品成本。 相似文献
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Synthesis and application of nonionic polyacrylamide with controlled molecular weight for fracturing in low permeability oil reservoirs
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Nonionic polyacrylamide (NPAM) with controlled molecular weight was successfully synthesized as a gel fracturing fluid by aqueous solution polymerization. The effects of the monomer concentration, initiator concentration, reaction time, feeding temperature and reaction temperature on the molecular weight were systematically investigated through single‐factor and orthogonal experiments. The NPAM molecular weight can be controlled by adjusting these factors. The decisive factor is the acrylamide concentration, whereas the initiator concentration and feeding temperature are secondary factors. These synthetic NPAMs can be crosslinked with zirconium acetate to produce a gel fracturing fluid for use in low permeability oil reservoirs. Gel fracturing fluids based on synthetic NPAMs have high shear resistance, low filtration performance, easy gel breaking performance, good proppant carrying capability and low core damage capability. By adjusting the NPAM or crosslinker concentrations, the gel fracturing fluid can be adapted for use in low permeability oil reservoirs for a wide temperature range (60–120°C). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41637. 相似文献
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Chlorosulfonated polypropylene: preparation and its application as a coupling agent in polypropylene-clay nanocomposites 总被引:1,自引:0,他引:1
Polypropylene nanocomposites containing organophilic layered silicate were prepared by melt mixing. In order to increase polypropylene polarity, Cl and SO2Cl groups were introduced by reaction with sulfuryl chloride under UV irradiation. Chlorosulfonated polypropylene was subsequently melt-compounded with organophilized montmorillonite clay to produce a masterbatch. The masterbatch was then blended with commercial isotactic polypropylene. An organophilized silicate (Cloisite 15A) and three chlorosulfonated polypropylenes with different degrees of functionalization were used in this study. The effect of various processing procedures was examined as well. The morphology of nanocomposites obtained was examined using TEM and X-ray diffraction. It has been shown that the presence of polar groups leads to an increased gallery distance and partial exfoliation. Nevertheless, full exfoliation of clay platelets has not been achieved. The observed morphologies affected the resulting tensile mechanical behaviour: both stiffness and strength significantly increased. 相似文献
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硅烷偶联剂对氢氧化镁表面改性及其在聚丙烯中的应用 总被引:1,自引:0,他引:1
选用具有相同亲水基团的4种硅烷偶联剂对工业级氢氧化镁进行常温湿法表面改性,并与聚丙烯(PP)熔融混合制得掺杂氢氧化镁质量分数为35%的复合材料,以SEM,FT-IR等手段对氢氧化镁及复合材料进行表征,考察了不同硅烷对复合材料阻燃性能和力学性能的影响。结果表明,硅烷偶联剂湿法改性可以提高氢氧化镁的分散性和与材料的相容性,改善氢氧化镁/PP的力学性能,但对阻燃性能影响不大;十二烷基三甲氧基硅烷在水相中稳定性好,可以较多地包覆于氢氧化镁表面,改性后材料的悬臂梁缺口冲击强度提高50%,断裂伸长率提高6倍,达到很好的改性效果。 相似文献
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Functionalized cellulose‐supported triphenylphosphine and its application in Suzuki cross‐coupling reactions
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A new heterogeneous cellulose tagged triphenylphosphine (Cell‐OPPh3) was synthesized and subsequently coordinated with Pd(OAc)2 to form a cellulose‐supported triphenylphosphine palladium complex (Cell‐OPPh3‐Pd). Cell‐OPPh3 and the corresponding palladium complex were fully characterized by TGA, SEM, TEM, and NMR analysis. Results of catalytic activity experiments indicate that the Cell‐OPPh3‐Pd complex can efficiently catalyze Suzuki–Miyaura cross‐coupling reactions of aryl halides with arylboronic acids at mild reaction conditions. The coupling products can be obtained in good to excellent yields (up to 98%). The work‐up procedure is simple and the catalyst could be easily recovered by filtration, and then reused in next run. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41427. 相似文献
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研究低滞后炭黑DZ-13的性能及其在载重轮胎胎面胶中的应用.与通用耐磨璎炭黑(N330和N234)相比,低滞后炭黑DZ-13的基本性能相当,表面活性较高,聚集体直径较大及分布较宽;与炭黑N234胶料相比,低滞后炭黑DZ-13胶料的加工性能较佳,拉伸性能和抗撕裂性能相当,生热较低,滚动阻力较小,弹性和耐热老化性能较好;与采用炭黑N234的载重轮胎胎面胶相比,采用低滞后炭黑DZ-13的胎面胶生热较低,变形较小,弹性较好;胎面胶采用低滞后炭黑DZ-13与炭黑N234并用的成品轮胎速度性能显著改善. 相似文献
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介绍了使用粉体物性测试仪测量、计算粉体流动性指数的方法。用化验室统一试验小磨将不同种类、不同掺入量的助磨剂与熟料共同粉磨,检验水泥的流动性指数。结果表明,流动性指数可以区分不同助磨剂相同掺入量和相同助磨剂不同掺入量水泥的流动性,可以作为水泥助磨剂评价与选择的参考。 相似文献
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The vapor‐phase polymerization of pyrrole to form conducting polypyrrole (PPy) films was applied to coat flexible poly(ethylene terephthalate) (PET) fabrics. A PPy‐coated PET fabric surface resistance of 200–20 000 Ω□?1 was obtained. The polymerization conditions, such as the concentration of oxidant and the reaction time and temperature, were systematically investigated. The coated fabric samples exhibited increasing temperatures when subjected to a fixed DC voltage. This result indicates the potential of these PPy‐coated fabric materials for heating applications. Copyright © 2009 Society of Chemical Industry 相似文献