涡流的形成

In this paper, combining the technique of parallel computation with the numerical method of 3D eddy current field, we designed the algorithms of generating mesh, forming finite element equations and solving them in parallel on a shared memory multiprocessor (SGI Challenge L 8 CPUs), and presented a concrete and effective method.

本文将并行计算技术和三维涡流场计算方法相结合，对三维涡流场有限元分析的并行处理技术进行了细致的研究，设计了基于共享内存并行计算机(SGI Challenge L 8 CPUs)的网格剖分并行算法和三维涡流场有限元方程形成和求解的并行算法，为数值求解实际三维涡流问题提供了一种有效途径和具体方法。

The existence of potential 〓、Ω is proved in linear functional space theories.

用线性函数空间理论证明了位函数〓、Ω的存在性；指出了现有文献在退化矢量位〓的唯一性证明中所存在的问题，并重新给予了证明；证明了位函数〓、Ω在导体与导体、导体与非导体界面上自然满足分界面条件；针对汽轮发机端部的轴对称涡流场，讨论了位函数〓、Ω的泛函及有限元代数方程组的形成。

To solve the problems that cyclic variation is high in low power output and NOx emission is high in high power output in compression ignition engine with compressed natural gas direct injection,a swirl chamber combustion system with glow plug ignition was developed.

针对缸内直喷压燃式天然气发动机低负荷循环波动大及高负荷NOx排放偏高的问题，设计开发了涡流室式热面点火燃烧系统，研究了涡流室通道尺寸对缸内天然气空气混合气形成、着火燃烧及发动机运转特性的影响。

The results do indicate that there may be several mechanisms for asymmetric vortical flow.

本文结果表明了大迎角旋转体非对称涡的形成机理可能是多种的，即给定分离线位置不对称或自由涡线的个别线段不对称都能产生非对称涡流。

In order to study the intake air flow characteristics in four-valve diesel engines, in this dissertation hot-wire anemometer and PIV twodimension instantaneous measuring technique are used. Extensive experimental study on two intake valve exit flow fields and longitudinal section flow field in cylinder are performed for different type of diesel engines. Great researching progress have been made on the interaction between two intake ports, and the formation process of in-cylinder swirl and flow field structure of cross and longitudinal section for four valve diesel engines. These results are presented in China for the first time and without such kind of research work reported abroad as detailed and deepgoing as this dissertation. The author designs and makes a set of hot wire measuring velocity device to measure the velocity distribution around the intake valve annulus and the cross section flow field in cylinder.

为了研究四气门柴油机进气过程中气体流动的变化规律，本文利用热线测速和PIV二维瞬态测速技术，对四气门柴油机两进气门出口全圆周流速场和缸内横、纵剖面的气体流动流场进行了大量的试验研究，在四气门柴油机两进气道之间相互影响的变化规律，缸内涡流的形成过程及缸内横、纵剖面流场结构等方面取得了重大的研究进展，这一研究工作在国内尚属首次，在国外也未见有如此全面、深入的研究报道。

He makes his flakes in a chamber that mimics the swirling balance between wind and gravity in which natural snowflakes form.

他在一个封闭的空间里制造雪花，这个封闭的空间模拟了风和重力之间形成的涡流平衡，天然雪花就是在这种平衡中形成的。

Much of it was, and is, in the central Pacific, where scientists believe as much as 100m tonnes of plastic jetsam are suspended in two separate gyres of garbage over an area twice the size of the United States.

科学家相信，在那里有着多达1亿吨的塑料漂浮物，分别悬浮于两个由垃圾形成的涡流上。这两个涡流围成的面积比两个美国还要大。

The true and false cavities of aortic dissection could be displayed on the SE T1WI,T2WI for the B type in 10 of 12 cases.With SE sequence,the true-false cavities did not be showed but the endomembranous pieces could be seen for A type of 2 cases of aortic dissection.

对于SE序列不能区别真假腔的2例A型夹层，轴位T1WI可显示剥离的内膜片。2例主动脉迂曲形成涡流的B型夹层，T1WI和T2WI不能区别真假腔，也不能显示内膜片，加行GR序列轴位扫描，可清晰显示等信号的内膜片。

The paper introduces the eddy formation,development and transmission on the pump S suction line with helps of experimental investigation and umerical simulation.

在试验研究和数值模拟计算的基础上，简述了泵吸入管中涡流的形成、发展和传递，论述了其基本特性，可供泵设计和运行调节时参考。

Rapids are created when rivers are on a steep gradient, making the water flow very fast, when the flow is constricted into a narrower channel, or where an obstruction such as a boulder interrupts the river, causing eddies and swirling currents.

当河流的坡度陡斜造成水流变快的时候，当水流被挤入更为狭窄的河道的时候，或是在河流被巨石之类的障碍物阻隔从而引起旋涡和涡流的地方，就会形成急流。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。