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高拉速高质量连铸生产是当前钢铁冶金领域中绿色低碳发展的重要路径。基于汽车板生产用1000mm×230mm断面连铸板坯结晶器内的钢水传输行为研究,探究一种行波磁场减速模式(EMLS)对水口侧孔射流及其钢坯质量的影响。根据电磁热流体与凝固传输理论建立了三维耦合数值模型,利用电导率等效法测试装置测量电磁力校验了模型的准确性,并提出了电磁控流作用下的结晶器综合冶金性能评价依据。结果表明,EMLS电磁力在结晶器宽面两侧呈大小相等、方向相反分布,最佳工作频率为4 Hz,其电流强度对电磁力的影响起主导作用。指出,当前浇铸条件下EMLS的最佳减速电流为200 A。此时,电磁力方向具有指向水口两侧出钢口且略微向下的特征,可以较好地控制其侧孔射流对初凝坯壳的冲刷强度,同时也避免了电磁力作用下弯月面波动过大和钢液冲击深度加深的问题。综合表明,合理利用行波磁场减速控流有望较好地解决当前常见的结晶器液面卷渣和凝固钩对夹杂物与气泡的捕捉,从而有利于提高后续IF钢冷轧板的表面质量。 相似文献
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《仪器仪表学报》2018,(12)
针对现有正弦压力信号源需要外加机械激励振动源,输出压力信号频率高,机械控制难度大等问题,设计出一种基于磁性液体的低频正弦微压力信号源。通过对螺线管线圈施加正弦激励电流对磁性液体施加磁场力,使之产生交变的磁浮力对外输出正弦微压力信号。研究对螺线管线圈参数进行优化得到较均匀的梯度磁场,计算了一定范围内输出正弦微压力信号与输入电流幅值及频率间的关系并对其影响因素进行简要分析。用有限元仿真方法得到模型内磁性液体中磁场分布及其所受磁场力分布并搭建实验平台进行测试。实验表明,该压力信号源在电源激励频率为0~2 Hz范围内输出的压力信号波形相对最稳定,调节输入电流的幅值与频率控制信号源输出低频正弦微压力信号。 相似文献
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采用有限元法对轴向混合磁悬浮轴承的磁场进行分析,应用三角剖分单元建立了磁悬浮轴承模型,在泛函分析基础上归纳出了磁位势的计算方程。根据所建模型,分析了永磁偏置磁场的磁通与磁感应强度分布特点、研究了电流控制磁场独自存在时的磁通分布和磁感应强度分布规律,描述了磁场力与控制电流的关系曲线。进而深入解析了永磁偏置磁场和电流控制磁场叠加条件下的磁通与磁感应强度分布特点,并得出磁场力与控制电流的关系。 相似文献
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基于有限元仿真软件COMSOL对某电磁阀的电磁铁进行仿真计算,得到了电磁铁磁场分布情况和磁感应强度分布情况,并对电磁力进行积分计算和对比。在磁路中磁感线密度较大,在其余位置存在少量的漏磁。磁感应强度在静铁芯与动铁芯较大,磁感应强度最大值在动铁芯中心处为0.93 T。该电磁铁的电磁吸力为8.8 N,电磁铁的漏磁系数为1.60。该研究对电磁阀的设计和研发具有一定的参考价值。 相似文献
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在给出圆薄板的非线性电磁弹性耦合运动基本方程及电磁力表达式的基础上,得到在横向稳恒磁场、环向电流和机械载荷共同作用下简支圆薄板的振动方程,并采用四阶Runge-Kutta法求解方程,得出圆板的弹性变形及应力状态.通过变化磁感应强度和电流密度,使系统由周期状态进入混沌状态;由分岔图与最大Lyaponov指数图判定系统是否进入混沌状态;并讨论磁场与电流对系统应力状态的影响. 相似文献
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电磁振动是电磁直驱型机床电主轴不可回避的振动来源,为了抑制电磁振动需要探讨其电磁力的频谱特征。推导了三相异步电主轴的电磁力波计算公式,重点分析了转子偏心状态下的电磁力波特点。基于Ansoft电磁场计算软件,建立了某国产电主轴的电磁场有限元分析模型,获得了电主轴的运行特性曲线。研究了转子在不偏心和偏心状态下的电磁力频谱变化规律,结果表明,静偏心会使电磁力力波成分更为丰富; 偏心的增加不会影响电磁力的阶次和频率分布,但与不平衡磁拉力的幅值和低阶力波幅值成正相关关系,将加剧电主轴的振动。 相似文献
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电磁冲击加载中,成形线圈是电能转化为磁场能的载体,使毛坯产生塑性变形的关键部件。介绍了平板线圈电磁驱动基本原理,通过ANSYS多物理场模拟平板线圈的简化模型,系统研究了线圈几何参数对轴向电磁力的影响;探讨了线圈驱动下驱动片上所受轴向电磁力分布规律及线圈参数对成形设备能量利用率的影响。仿真结果显示:随线圈匝数增加电磁力呈指数增加,随匝间距的增加呈指数减少,随起点距呈近似指数减小;轴向电磁力在线圈距中心轴2/3区域达到最大值;减小电感值有利于提高成形效率。 相似文献
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V. B. Remezov 《Russian Journal of Nondestructive Testing》2013,49(7):365-373
Modern computer technology makes it possible to visualize different processes that take place in real time and to limit them to a specific plane using 3D-graphs. This paper describes the distribution of eddy currents and the configurations of the primary and secondary electromagnetic fields generated by a coil located above a half space. These curves make it possible to estimate the field intensity at any point of the center line. All curves are plotted for their vector potential, which is one of the main characteristics of an electromagnetic field. Knowing the value of the vector potential, it is possible to determine all the characteristics of an electromagnetic field, i.e., the intensity and induction of electric and magnetic fields and the density of eddy currents for an electrically conductive material. The developers of eddy-current equipment that is used for inspection purposes need to know these characteristics. In this case, it is possible to determine the optimal geometry of the transducer and select the frequency and amplitude of the field-coil current at the design stage. The aim of this paper is to show the possibility of the representation of electromagnetic fields on the basis of modern computer graphics. 相似文献
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Hyung-Sub Bae Young-Won Yun Myeong-Kwan Park 《Journal of Mechanical Science and Technology》2010,24(2):583-592
This research analyses the dynamic behavior of magnetic fluid that sloshes due to the pitching motion of the container. To
analyze the behavior of magnetic fluid, we first analyze the equations that govern magnetic fluid as well as the momentum
equation of the sloshing that results from a magnetic field. In each case, we conducted simulation and compared the results
from simulation with those from experiments. When sloshing does not occur, the surface of the magnetic fluid rises towards
the location of intensity of the magnetic field; in the absence of an additional, external body force, the fluid remains elevated.
In case sloshing occurs simultaneously with the application of the magnetic field, the elevation of the surface as a result
of the magnetic field is maintained. Further, we can confirm that if the excitation frequency of sloshing is small, the wave
motion of the surface is small because the magnetic body force dominates the effect of sloshing. Even if the excitation frequency
increases, the wave motion of the fluid surface is smaller than when a magnetic field is not applied. The fluid surface rises
in that location where the intensity of the magnetic field is strong. Where the intensity of the magnetic field is weak, the
height of the fluid surface is lower than the initial level that obtains in the absence of a magnetic field. Through the study,
we can conclude that the sloshing behavior of magnetic fluid is influenced by the magnetic field intensity and distribution. 相似文献
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以GSC3型AC接触器为例,运用“场”、“路”结合的方法求解电磁参数:大气隙时应用三维有限元非线性静态分析,求出不同气隙和励磁电流下的电磁吸力值,而在小气隙时考虑分磁环的作用,引用磁路的方法简化此时的电磁吸力的计算,得到了各状态下的磁系统的磁场分布图形,构造不用气隙、电流下电磁吸力的二维数据表,并最终完成整个过程的插值... 相似文献
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介绍了一种应用于高压线故障检测节点的非接触式自取电电源.该电源从高压母线电流周围产生的磁场中获取能量,能够持续平稳地对外供能.电源利用特制的电流互感器,可以在较小的母线电流下开始工作,同时,采取了控制线圈电路、泄放电路和瞬间分流技术相结合的多重保护措施,能够在大母线电流下确保安全,从而针对性地解决了高压线上故障检测节点的电源问题. 相似文献
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在连续铸轧过程中,将电场与磁场施加于固液态区产生一起伏变化的能场,这种多维变化能场驱动铝合金产生无序流变,同时产生的行波力与脉动力对长大中的晶粒具有破碎作用,使晶粒细小均匀,从而提高了铸轧材料的力学性能。本文根据铝合金电磁铸轧对电磁场的要求提出了一种铝电磁场快速铸轧变频控制系统,分析了系统的工作原理,建立了MATLAB的仿真模型,仿真结果表明:这种新的主电路方案是可以达到电磁铸轧的电磁感应器对电流的要求,不存在使电源短路的问题,控制起来更简单。试验表明,此系统可以对电磁感应器产生的复合磁场进行控制,系统控制精度高、可靠性高,动态性能好,满足铝电磁场快速铸轧的基本要求。 相似文献
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Although continuous casting process has highly developed, there still remain many problems to be considered. Specifically,
two vortex flows resulting from impingement against narrow walls make a flow field unstable in a mold, and it is directly
related to internal and external defects of steel products. To cope with this instability, EMBR (Electromagnetic Brake Ruler)
technique has been lately studied for the stability of molten steel flow, and it is revealed that molten steel flow in a mold
can be controlled with applied magnetic field. However, it is still difficult to clarify flow pattern in an EMBR caster due
to complex correlations among variables such as geometric factors, casting conditions, and the place and the intensity of
charged magnetic field. In the present study, flow field in a mold is focused with different conditions of electromagnetic
effect. To accurately analyze the case, three dimensional low Reynolds turbulent model and appropriate boundary conditions
are chosen. To evaluate the electromagnetic effect in molten steel flow, dimensionless numbers are employed. The results show
that the location and the intensity of the applied magnetic field significantly influence the flow pattern. Both impingement
and internal flow pattern are changed remarkably with the change of the location of applied magnetic field. It turns out that
an insufficient magnetic force yields adverse effect like channeling, and rather lowers the quality of steel product. 相似文献
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通过特殊设计的电路及作用线圈制作了交变磁场发生装置,并用其研究了不同磁场强度对激光熔覆铁基涂层宏观形貌和显微组织的影响。基于电磁学及金属凝固原理,揭示了激光熔覆涂层的固化过程和磁场诱发熔覆涂层柱状树枝晶向等轴晶转变的主要机制。实验结果表明:在交变磁场作用下,熔池金属液表面产生的趋肤效应和交变电磁力使凝固后熔覆层的表面形态呈波浪式,熔高和横截面积均随磁场电流的增加而减小,但熔宽变化不大。熔池内部产生的电磁力驱动熔体流动使树枝晶熔蚀和机械折断,游离的破碎枝晶成为新的形核核心,增加了形核率,从而促使熔覆层顶部组织由树枝晶向等轴晶转变。随着磁场电流的增加,等轴晶区扩大,但涂层底部的组织变化不明显。 相似文献