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本文用流体网络理论建立了用于油田注水系统的压力滤波器的数学模型,开发了用于分析压力滤波器衰减特性输入阻抗和损失的软件,找到了压力滤波器的结构参数对管路脉动特性的影响规律。 相似文献
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在测量超导磁通量子比特信息时,给出了低通和带通两种测量电路。低通电路采用双绞线,通过RC滤波器、铜粉滤波器,再接到样品上。该方法可以用于测量DC-SQUID结的跳变电流统计分布,从而获知量子比特的信息。带通电路用微波同轴线作为导线,通过衰减器、铜粉滤波器到样品上,再通过电容接地。该方法可以用于测量超导量子比特的量子化能级、迟豫时间、Rabi振荡等特性。 相似文献
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目的比较3种滤波器在平板表面波纹度测量中的传输特性差异。方法采用2RC滤波器(JIS B 0610)、指数滤波器(SEP 1941)和高斯滤波器(ASME B46.1),通过频谱分析原始轮廓与不同滤波器得到的波纹度轮廓的频谱特性,对比波纹度参数差异。结果 3种滤波器的幅值特性没有振荡现象,但是高斯滤波器和指数滤波器的幅值下降速度较快,高斯滤波器和指数滤波器在截止波长处的幅值下降50%,2RC滤波器在截止波长处的幅值下降25%。高斯滤波器和指数滤波器属于无相位移动滤波器,2RC滤波器属于有相位移动的滤波器,在截止波长位置的相位移动约为1.05。在相同的截止波长下,指数滤波器与高斯滤波器的传输特性完全一致。进一步研究表明,采用2RC滤波器得到的波纹度参数Wa比采用高斯滤波器得到的高0.1μm。结论高斯滤波器和2RC滤波器均无法同时完全抑制截止波长范围以外的成分而完全保留截止波长范围之内的成分。 相似文献
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Purification of solar cell silicon materials through filtration 总被引:2,自引:0,他引:2
Silicon is the material most commonly used in the manufacturing of photovoltaic (PV) cells. In the current study, laboratory experiments of purification of solar cell silicon materials through filtration are carried out. Inclusion removal from silicon was investigated. The purpose is to achieve clean silicon materials for solar cells. Silicon samples and filter samples were analyzed using microscopeobservation, EPMA, and X-ray detection. Silicon nitride (Si3N4) and silicon carbide (SiC) particles are the main non-metallic inclusions present in top-cut silicon scrap. Almost all inclusions larger than 10 μm can be removed from silicon by the porous foam filter. In mass fraction, more than 90% inclusions areremoved. Si3N4 particles are mainly removed on the top surface of the filter, and SiC particles are mainly removed by entering the pores and attaching tothe filter material. SiC inclusions are not only simply attached on the surfaceof the filter material, but are found also inside the filter material. There are SiC bridges near the filter materials. These bridges may fill the spaces between filter material, and this will further retard inclusions passing through the filter. Three-dimensional turbulent fluid flow and inclusion motion in the filter was calculated. Both experimental observation and fluid flow simulation indicate that most of the inclusions are entrapped at the upper part of the filter. 相似文献
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按照国内现行的多次通过试验标准,滤清器是在一个稳定流量条件下试验至滤芯终止压差。而在滤清器实际使用条件下,滤芯是随流体系统运行而过滤,随流体系统的关闭而停止过滤。在标准状态下多次通过试验不能很好地复现流体系统反复开关的运行条件,因此有必要通过试验模拟工况运行。根据多通标准试验结果与模拟流量反复开关情况下的试验结果,对比两者过滤比的差别并进一步探究原因。 相似文献
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在高转速柴油机的高压共轨喷射系统中,前一次喷油所产生的水击压力波会对后一次喷油的精度产生较大影响。建立共轨管三维模型,以基于格子玻尔兹曼方法的计算流体力学仿真软件XFlow模拟共轨管内的压力波动,并总结了H型滤波器的关键参数对波动抑制效果的影响规律:随着滤波器容腔容积、小孔长度和小孔直径的逐渐增大,波动幅度均呈现先减小后增大的趋势,均存在最佳滤波尺寸,分别为6 283 mL、2 mm和3 mm,即滤波器存在最佳滤波尺寸组合,并根据电液相似理论分析了存在这种趋势的原因。最后在滤波器最佳滤波尺寸组合下验证了1.5、2.5、3.5 ms喷油脉宽下的滤波效果,其滤波衰减率分别达到60.3%、76.2%、63.8%,证明在一定范围的喷油脉宽内均有较好的滤波效果。 相似文献
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Ceramic filters are used to avoid slag and impurities in foundry applications. When not properly applied, the presence of these filters may have a significant influence on mould filling. 3-D casting simulation has been applied to study the effects of the use of a ceramic filter on the metal flow in a gating system. Instead of using a pressure drop model to represent the behaviour of a fluid metal flow passing through a filter, a real exact filter geometry, which is created by a high resolution CT-scan and a non-destructive imaging technique, in the gating system is applied in the simulation. In this research, nodular cast iron is poured into a block casting. A depressurized gating system is used. After a choke, a filter with different orientations is placed in the system. Mould filling coupled with temperature is simulated. Geometries using different orientations of the filter, and without the filter have been researched. The simulated results show that the filter has no influence on the pouring time of the casting if the choke section is small enough compared to the effective section of the filter. Although the filter has no significant influence on the flow patterns in the block casting itself, the flow patterns in the filter zone are different. When the liquid metal passes a horizontal filter, it will be broken into many small streams and show a shower effect. After the part under the filter is full, the shower effect disappears. When the filter is located at the vertical position, due to the gravity, the shower effect is less. If no filter presents on the system, the liquid metal passes through the filter zone with a high speed and causes surface turbulence. 相似文献
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论述了铸造合金的液态结构、表面张力、流动产生的扰动及真空对铸造合金深过滤的影响,并从流体力学的角度提出了过滤器设计的基本要求 相似文献
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热镀锌过程中,炉鼻子内需通入加湿气体以抑制锌液面处锌灰的产生。安装在炉鼻子外部的锌灰循环过滤系统可以有效过滤锌灰,防止锌灰聚集,避免造成带钢表面缺陷。为了科学合理地设计炉鼻子外部锌灰循环过滤系统,采用计算流体力学方法对炉鼻子内部流场进行了模拟计算,研究了炉鼻子开启锌灰过滤系统后其保护气流场、锌灰捕集效率、水蒸气含量等参数的变化规律,得出了炉鼻子锌灰过滤系统抽气口高度和抽气量的最佳参数组合。经实际使用验证,改善锌灰缺陷效果显著,为炉鼻子锌灰过滤系统的设计、安装和调试提供了技术支持。 相似文献
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