涡片

The flow visualization of the different afterbody of the airliner ;2. The flow Visualization of different afterbodies of airliner is undertaken with the fluorescence and the laser light sheet method in the water channel of BUAA.

利用荧光黄纳及片光在水槽中对具有不同收缩比的民机后体的复杂绕流进行流动显示，探讨了后体的分离尾涡特性及参数影响，实验发现后体收缩比改变时对应了两种典型的尾涡流态，即稳定流向尾涡和周期性尾涡，并进一步探讨了尾翼对后体尾涡的影响。

Hence, we first analyzed and studied the kinematics and dynamics of PDC bit, and that are utilized to analyzed how to hame cutters by PDC bit whirlpool. Onthe based of this, we do the cutting experiments. With the test, we not only think over the influence to force actting on cutters in rock nature, drilling parameter, cuttersdensity distributed, and also wear state of cutters and PDC bit appearance. Because the PDC bit's cutters are repeaded by polycrystalline-diamand and tungsten carbide, the specific property of PDC wear are not alike that of polycrystalline-diamand and not alike tungsten carbide.

因此，本文首先分析研究了PDC钻头的运动学和动力学，并利用分析的结果对PDC钻头的涡动是如何损坏切削齿的进行了探讨；在此基础上，进行了PDC钻头切削齿的受力实验，在受力实验研究中，不仅考虑了岩性、钻进参数、布齿密度等对切削齿受力的影响，而且考虑了切削齿不同的磨损状态、钻头的冠部形状对切削齿受力的影响；PDC钻头的切削齿是由聚晶金刚石层和碳化钨底层复合而成的，它的磨损特点既不同于金刚石的磨损又不同于碳化钨的磨损，因此，在分析了复合片磨损机理的基础上，进行了PDC钻头切削齿的磨损实验。

This staggered path configuration defines an elongated, tortuous path having a length greater than a height of the stack for eddy currents through the lamination stack, to increase impedance of an eddy current path therethrough.

此曲折路径的构形形成一条细长的曲折路径，对于通过该叠层片的叠放体的涡漩电流来说，其长度比叠放体的高度要长，从而提高了从中通过的涡漩电流的阻抗。

A multiminate layer vapor screen technique and force measurement technique for an unsteady flow in the intermitted wind tunnel is presented in this paper.

本文介绍在暂冲式三声速风洞中实现了非定常流动的多片光蒸汽屏显示技术和测力技术，并用这两项技术研究了亚声速时70°后掠三角翼模型俯仰振动的非定常流动现象，探讨了由于三角翼模型俯仰振动产生的涡结构与纵向气动力特性之间的相关关

The seal element of scroll tooth which is made of lubricative material and wearable board in the bottom of scrolls.

在涡旋齿端面开设密封槽内加由自润滑材料制成的密封条，同时在涡旋盘底平面加耐磨片，它们不但可以阻止泄漏，而且降低了涡旋齿与涡盘底部摩擦功率损失，在此提出了它们的设计方法。

Professional production: tension springs, pressure springs, multi-project spring, scroll springs, plate springs, leaf spring, butterfly springs, bell, candle cup, hinge, wind bell tube, aluminum chain, twisted chain, wave sub-chain, O word chain , snake chains, axes

专业生产：拉力弹簧，压力弹簧，多工程弹簧，涡卷弹簧，板弹簧，片弹簧，蝶形弹簧，铃铛，烛杯，合页，风铃管，铝链，扭链，波子链，O字链，蛇链，轴心，异型螺丝，螺母，螺钉等精密五金零部件。

Moreover, to prevent the vorticity from entering into the body, the concept of "residual vorticity" is introduced in the sense that partial circulation of the vortex sheet is remained at the boundary without being diffused into the flow field. Blobs very close to the wall are thus unnecessary.

为避免部分新涡泡太过接近边界，我们引入了「残留涡度」的概念，将离边界甚近之环量转为涡片形式留在边界上，以减少环量进入物体内部之误差。

To simulate the diffusion of the vortex sheet into the flow field as time goes on, Koumoutsakos' analytical solution is employed, in which an effective vorticity flux is derived and used for solving the vorticity diffusion equation.

而涡片之环量随时间扩散进流场之现象则藉由Koumoutsakos之理论，以边界上之等效涡度通量求解扩散方程式，得解析解后，再将之离散为边界附近之新涡泡。

To simulate the diffusion of the vortex sheet into the flow field as time goes on, Koumoutsakos' analytical solution is employed, in which an effective vorticity flux is derived and used for solving the vorticity diffusion equation. The solution is then discretized into blobs (called "-blobs") in the vicinity of the boundary.

而涡片之环量随时间扩散进流场之现象则藉由Koumoutsakos之理论，以边界上之等效涡度通量求解扩散方程式，得解析解后，再将之离散为边界附近之新涡泡。

Moreover, blobs may move too close to the boundary because of advection errors or other numerical errors. It may cause serious fluctuations in evaluating the strength of the vortex sheet. In order to reduce the fluctuations, these near-wall blobs are also manipulated in use of the concept of "residual vorticity". Finally, we apply the so-developed solver to a simulation of the flow past an impulsively started circular cylinder at different Reynolds numbers.

此外既有涡泡也可能因对流或其他数值误差造成过於靠近边界，因此我们也设计一专门处理过於靠近边界涡泡之方法，以其他计算元素取代这些涡泡，降低进入物体内部之环量，进而降低涡片强度计算上的扰动。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。