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101.
102.
103.
转/静干扰效应纳入设计体系的途径探索 总被引:3,自引:1,他引:2
1前言近年来,叶轮机非定常流动时间精确模拟获得十足发展。虽然如此,关于时间精确解仍然存在很多问题。因而就目前而言,将叶轮机非定常干扰时间平均效应纳入设计体系,实现准四维设计体系是缩短我国和发达国家叶轮机气动设计水平差异的关键工作,其中叶轮机非定常流动时均流动模拟方法是首要解决的问题。叶轮机时均流动模拟工作,国外主要有Adamczyk[llRhie[‘]国内作者和孟庆国博士也开展了研究[‘-’],其中文献问详细阐述了时均流动模拟理论和方法,并对时均流动模拟基本方式进行分类(图1)。2反映转/静干扰效应的时均N-S… 相似文献
104.
H. Burkhard 《Applied Physics A: Materials Science & Processing》1975,6(3):357-362
Superconducting coils with an inhomogeneous current density distribution yield more field for less volume of superconductor.
The advantages of these systems are lower costs and an improved cooling. The latter is important for high field magnets. Mechanical
stresses induced by the electromagnetic forces are the limiting factor in designing such coils. The inhomogeneous current
field is produced by a set of concentric subcoils. The radial and tensile stresses and the radial displacements in the subcoils
are calculated. This calculation requires the field-shape in the coils. An exact calculation shows a linear decrease of the
field with the radius in each subcoil. Thus the stress-calculations are very simple and one does not need a computer. As an
example this method is applied to a 10 T-magnet with three subcoils. In this case the results of our exact calculation differ
from the approximation of Kilbet al., Steklyet al. and from the magnetic pressure estimateB
2/2μ
0 up to a factor of three. 相似文献
105.
Michail W. Zhelamskij Pierluigi Bruzzone 《Physica C: Superconductivity and its Applications》1998,310(1-4):262-266
A special sensor is proposed for magnetization measurement of superconductors with round cross section under pulsed transversal field. The sensor consists of a saddle shaped pick-up coil attached to the cylindrical superconducting sample, with a controlled geometrical distribution of the turns. The pick up coil carries out a two-dimensional flux integration and the software calculates the loop area in Joules. The sensor has been used during a campaign of ITER subsize conductor tests, showing an excellent agreement (better than 1%) with the results of boil-off calorimetric measurements. The detailed design, the algorithm and the test results are discussed in the paper. Other applications of this test method are proposed. 相似文献
106.
VISCOMETRIC INVESTIGATIONS OF POLYVINYLPYRROLIDONE IN MIXED SOLVENTS AND WITH VARYING TEMPERATURE 总被引:1,自引:0,他引:1
OmarMelad OmarAbu-Tiem RajaiBaraka 《高分子科学》2005,(4):367-371
The viscosity behavior of polyvinylpyrrolidone (PVP) has been determined at 25℃ in mixed solvents comprising water/dimethylformamide (DMF) and water /methanol (MeOH). Analysis of the data has considered the PVP as being both host and guest polymer in solution. The intrinsic viscosity of PVP in DMF is higher than in water and in MeOH, but also increases in a mixed solvent with high water content because of the effect of polymer-solvent interactions. It was also found that the intrinsic viscosity of PVP at finite concentration, [ηpvp]c decreases with an increase in the concentration of PVP in solution. The viscosity behavior of PVP in a mixed solvent is affected by the concentration-dependent intermolecular excluded volume effect, which can be quantitatively expressed by the parameter, bY, which reflects the shrinkage of PVP chain coils, resulting in a decrease of [ηpvp]c. The effect of temperature on the viscosity behavior of PVP in MeOH shows that the interaction parameter increases up to a maximum value, and then decreases after a certain temperature. 相似文献
107.
108.
设计了HL-2M 环向场线圈基本形状、特殊的指形接头和斜面接头以及馈线、绝缘结构和水冷回路。每个环向场线圈由L 形中心段、上弧段和外弧段分别通过指形接头和斜面接头组装成完整的D 形线圈。分段可拆卸的D 形线圈结构可以使得真空室和单个极向场线圈分别整体吊装到环向场线圈内侧。单根引线和双回线的馈线结构既能节省装置空间,又能降低杂散磁场。TF 线圈匝间绝缘500V,对地绝缘30kV。采用软焊在线圈旁侧槽内的铜管对线圈进行水冷以带走线圈放电产生的焦耳热。 相似文献
109.
通过测量HL-2M 装置环向场线圈指形接头及斜面接头上的若干个点的空间坐标,利用点到平面的距离最小二乘原则,对环向场线圈的外轮廓平面进行拟合。再利用各外轮廓平面与中心轴的空间位置关系,求解得出环向场线圈中心轴倾角。通过简化模型及数值模拟求解出在不同的空间点坐标测量标准差情况下的中心轴倾角。在空间点三维坐标低测量标准差的情况下(σ=0.05mm),拟合求得倾角的相对误差为0.10‰,相对标准偏差为 1.21‰。 相似文献
110.
介绍了HL-2A装置上同心圆逆磁测量的原理以及同心圆系统的设计,包括线圈面积差的确定和积分电路的设计。对实验数据的分析表明,通过对杂散场的有效补偿,同心圆逆磁测量系统可获得较高的信噪比,能够在一些较复杂的放电条件下可靠地获取等离子体逆磁信号。 相似文献