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为得到水工弧形闸门正常运行时在船舶撞击作用下的动力响应,预测了闸门可能出现的破坏模式,评价了闸门结构安全并探寻有效的防护措施,采用非线性有限元数值方法,考虑闸门材料的弹塑性、失效及结构大变形,模拟船舶正面撞击弧形闸门过程,分析了弧形闸门结构瞬态动力响应。计算结果表明,闸门结构安全防护重点区域为垂直隔板、边梁与上主横梁相交的部位,闸门支臂结构的振动明显,其动力稳定性问题需引起重视,并提出加大隔板、边梁的梁高,提高钢材强度,增设加劲板及在闸门上游适当高程设置横跨于闸室的柔性防撞缆索,以吸收撞击船动能,减小撞击荷载等安全防护措施。 相似文献
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针对大跨度弧形闸门结构受力复杂且易发生弯曲变形和振动问题,采用有限元软件ANSYS对弧形闸门进行分析计算,对闸门主要部件的应力状态及变形情况进行了校核,分析了闸门自振频率的影响因素,全面评估了闸门的安全性能。并以目前国内跨度最大的某弧形闸门为研究对象,对不同工况下闸门的刚度和强度进行了计算,考虑流体与闸门之间的流固耦合作用,利用附加水体法分析了水体对闸门自振频率的影响,同时还研究了不同开度闸门自振频率变化情况。结果表明,弧形闸门总体强度和刚度满足设计要求,主要部件存在局部应力集中;水体作用使闸门的自振频率有一定程度的减小;随开度的增加,闸门的振动频率有不同程度的增加。 相似文献
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为保证在役大型弧形闸门安全稳定运行,以葛洲坝工程水工弧形闸门为例,利用有限元分析软件,按设计水头对其进行静力学强度和模态分析,得出闸门最大应力集中点及变形情况,并根据自振频率、振型和最大变形位移判断闸门振动强弱。结果表明,闸门设计总水压力与理论计算偏差为4.7%,在5.0%误差控制范围内,弧形闸门整体最大应力为373.86 MPa、变形为12.938 mm,强度和刚度均能满足现行规范设计要求,面板底部存在局部应力集中,闸门整体振动变形量小于0.508 mm,振动强度不大,只有低阶频率出现在水流脉动压力的高能区,其发生共振的可能性小。 相似文献
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浮箱式钢闸门三维有限元分析 总被引:1,自引:0,他引:1
基于大型有限元分析软件ANSYS,针对某大型浮箱式钢闸门的工作特点和受力方式,研究了浮箱门结构的三维有限元计算模型。通过不同工况的结构仿真计算,详细研究了浮箱门在各种控制情况下的变形和应力变化规律,对闸门的强度和刚度进行校核,并对闸门安全性进行了评估。 相似文献
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为改善水工钢闸门主梁腹板的应力分布,减小主梁挠度,提出了一种新型的主梁结构即实腹式双拱形主梁。以某露顶式拦河蓄水闸为例,利用有限元软件ANSYS分别建立了梯形变截面梁腹板模型和双拱形变截面梁腹板模型、梯形变截面主梁闸门和双拱形主梁闸门模型,对两种主梁和闸门分别进行静特性结构分析,比较两种主梁腹板和闸门各构件的应力及变形。结果表明,双拱形变截面梁闸门各个构件的最大折算应力比梯形变截面梁闸门基本小8%以上,位移挠度比梯形变截面梁闸门小14%左右。说明在强度安全和刚度校核时,双拱形变截面梁闸门优于梯形,在水工钢闸门主梁优化及设计时,可考虑采用双拱形变截面主梁。 相似文献
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鉴于扇形中枢旋转门是一种结构新颖的闸门,其过流流态与传统闸门有显著区别,为研究扇形中枢旋转门的动水压强特性,基于吴淞江整治工程60 m大孔闸及其消能设计工况,对闸门不同开度系数进行模型试验,分析了不同开度系数条件下的时均压强、平均波动幅度、脉动强度、频谱特性。结果表明,各开度系数下,门叶时均压强均为正压;总体脉动压强幅值较平稳,各测点在不同开度系数下脉动压强接近正态分布;脉动强度大小随开度和测点位置的变化而变化,随着开度系数的增大,脉动强度呈先减小后增大的趋势分布,脉动压强属于低频脉动;宽度方向测点位置的变化会对测点脉动强度的大小产生影响,可用中线位置脉动强度代替整体模型脉动强度。 相似文献
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《International Journal of Hydrogen Energy》2022,47(63):26789-26797
The issues related to the reliability of hydrogen engines of unmanned vehicles and increasing the efficiency of using hydrogen as fuel when using the method of its production during the decomposition of hydrogen-containing molecules of liquid-phase organic compounds in a plasma discharge under the action of intense ultrasonic exposure are considered. Experiments have shown that as a result of decomposition in the acoustoplasma discharge of liquid hydrocarbons, solid-phase carbon-containing products are formed, chemical transformations occur in the liquid phase and hydrogen-containing combustible gas is formed. Hydrogen-containing gas can be used as fuel immediately after synthesis, i.e. it does not require separation, since in addition to hydrogen it contains only impurities of CO2 and water vapor. The purpose of the study is to formalize the basic conditions for tightening the control of mutual compliance with the efficiency of hydrogen engines of the same series in the conditions of their mass production. Methods of mathematical statistics and hardware-software modeling were used in the study. The term “unerroric of quality mutual compliance control” is introduced to describe a set of hardware and software tools for such control. The principle of in-depth testing of the technical condition of such engines of one series is described in a multidimensional formulation of the quality control problem for three of their operating parameters at once. The conditions for increasing the mutual correspondence of the measured values of such parameters in the conditions of serial production of hydrogen engines are formalized. 相似文献
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Linear and nonlinear analyses of the instabilities and distortion of liquid streams injected into a gaseous media are discussed. The various fundamental mechanisms and the predictive capabilities for the distortions are emphasized. Round jets, planar sheets, annular sheets, and conical sheets are discussed in detail. The balance between capillary and inertial forces is primarily examined. The method for simplifying the analyses in the case of thin liquid sheets is discussed. The capabilities for representing the droplet size distribution that follows the stream disintegration are outlined. 相似文献
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基于《水工混凝土掺用氧化镁技术规范》中的Ⅰ型氧化镁(MgO),研究了该型MgO膨胀剂(MEA)细度对掺粉煤灰水泥浆体膨胀性能的影响。即采用X射线衍射分析(XRD)及同步热分析(TG DSC)分析了掺MEA水泥浆体中MgO的水化性。结果表明,养护温度相同时,MEA的细度对水泥浆体内MEA中MgO的水化和水泥浆体的膨胀无显著影响,产生的膨胀均能补偿水泥浆体的收缩;MEA的细度可从试验设计采用的45 μm筛筛余15%左右增加到30%左右,这将有利于MEA生产企业的节能降耗。 相似文献
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使用ANSYS8.0软件对高速列车车轮进行了三维有限元分析,计算出车轮在直线、曲线和道岔条件下牵引、制动共6种工况时孔边薄弱部位的应力,分别通过Mises等效平均应力方法、Sines平均主应力方法和应力分量中考虑平均应力方法计算出应力在极值位置时的等效应力幅、等效平均应力,从而进一步算出车轮的安全系数,对其疲劳强度进行评定,并对3种方法进行了比较研究。 相似文献
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M.R. Salimpour M. SharifhasanE. Shirani 《International Communications in Heat and Mass Transfer》2011,38(1):93-99
This paper documents the geometric optimization of an array of circular and non-circular ducts. The optimization was carried out numerically using finite volume method. As optimal dimensions were independent of the array configuration, the numerical simulation was performed on a unit cell. Numerical optimization for circular, square and isosceles right triangle cross-sections of channels was performed. Based on the results of this investigation, some correlations were proposed to predict the optimal hydraulic diameter and dimensionless heat transfer per unit volume. In addition to examining the effect of pressure drop on these parameters, it was showed that among the different geometries of this study, square cross-section has the most efficiency for a given volume. The numerical results of the present study were compared with approximate results reported in the literature which a good agreement was observed. 相似文献
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本文对漫灰均温物体在常物性条件下对外辐射传热的Yong值计算建立了数学模型。通过与物体内能Yong公式的数值计算比较,得出了辐射能量的Yong值不大于内能Yong值的结论。从初步的热射Yong值计算公式发现。Yong与物体表面辐射率有关。 相似文献
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《International Journal of Hydrogen Energy》2022,47(83):35515-35526
The main purpose of this work is to propose a new method to evaluate the concentration distribution of the hydrogen jet by using a He–Ne laser through the jet. This research attempts to apply the expression of concentration Gaussian distribution, the refraction formula of inhomogeneous refractive index medium, and the concentration inversion function to disclose the displacement of the center of the laser spot at different heights in the gas jet. The spot images of the laser beam passing through the gas jet at three vertical heights z = 10d, 20d, 30d, and different radial positions are obtained. The radial spatial asymmetry of the gas jet is also found in the experiment. Finally, the calculated concentration distribution curve and the fluent simulation curve, it is found that the two results are very similar. Our findings show that the error between the concentration distribution of this method and the simulated concentration distribution reaches 2.43%. 相似文献
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General expressions for the heat of vaporization of mixtures at constant pressure; at constant temperature; and at constant pressure, temperature, and composition are proposed. The last one is related to the liquid-vapor interface where steady vaporization or condensation is taking place. Numerical examples by the proposed expressions are shown for binary mixtures of HCFC22(R22) and (HCFC123(R123) © 1997 Scripta Technica, Inc. Heat Trans Jpn Res, 25(1): 12–24, 1996 相似文献