流阻

The number of elementsin this flow-resistor network can be determined by the tracheid length,radial diameter andtangential diameter of tracheid and the dimension of specimen.

根据Zimmermann有关实验结果以及气体在针叶材中流动的路径，气体在试件内的流动通道分成为不同的区域，气体将不会在这些区域之间流动，即各区域间的流阻不相连接；且这样的区域在三个纹理方向的管胞数目相同都等于管胞在试件纵向排列的数目。

The flow-resistor network and corresponding formula are derived from the structural modelof tracheid,dynamics of fluids and percolation theory,moreover it has been verified by themeasurement.

木材径向和弦向渗透在木材干燥、木材浸渍改性中有较多的应用，这样就使得本文关于针叶材气体渗透三维流阻网络理论具有较大的实际应用意义。

The calculated results of the average total pressure loss in the modul of MPC system at four different ...

四种不同流出角的MPC模块平均总压损失计算结果表明，已开发的软件可作为设计低流阻MPC模块的良好工具。

Comparison of end wall heat transfer and pressure drop characteristics was made between two kinds of rectangular clapboards and two kinds of waved clapboard in the turbine blade trailing edge complex passages.

主要讨论了在通道其它结构均相同的条件下分别采用4种不同结构的隔板（2种孔径的矩形隔板与2种孔径的波形隔板），研究隔板中孔径大小对通道换热和流阻的影响。

Experimental results indicate that the B/A value greatly affects the internal Nusselt number and friction factor of the twisted tube because the parameters decrease with the increase of B/A and S/d values, more rapidly with the former, and that the Nusselt number and friction factor of the twisted oblate tube increase respectively by 30%~150% and 20%~50%, as compared with those of the smooth tube at the same Reynolds number and Prandtl number.

实验结果表明：高扭曲比螺旋扁管的管内努塞尔数和阻力系数均随B/A值和S/d值的增大而减小，但随B/A值的增加而减小得更快，B/A值对高扭曲比螺旋扁管的管内传热与流阻性能影响更大；在相同雷诺数和普朗特数下，高扭曲比螺旋扁管管内的努塞尔数为光滑管的1.3~2.5倍；阻力系数为光滑管的1.2~1.5倍。

The experimental results indicate that, over a ranger of tube side Reynolds number and Prandtl number (Re=4000~20000, Pr=6~7.5), the internal Nusselt number and friction factor of spiral-flat tube increased by 30%-150% and 20%-50% respectively compared with smooth tube at the same Re and Pr. The value of friction factor decreases with increasing the value of B/A as well as increasing that of S/de, and the same phenomena can also be observed for Nusselt number.

实验结果表明：管内Nu和f值均随均随B/A值和S/de值的增大而减小，但随B/A值的增加而减小得更快，B/A值对螺旋扁管管内传热与流阻性能影响更大；在相同Re和Pr下，螺旋扁管管内Nu数为光滑管的1.3～2.5倍；阻力系数f是光滑管的1.2～1.5倍。

Also the biggest pressure loss is caused by rectangular winglets and the less is that of delta winglets and trapeze winglets with a bevel angle φ=0°.

矩形翼压力损失最大，直角三角翼和φ=0°梯形翼流阻较小。

The thorough knowledge of the gas permeability of softwoods can be gained by the flow-resistor of tracheids for the flow of gas.

本文从针叶树材管胞解剖结构出发，运用流体力学理论，导出了管胞 3个纹理方向渗透气体流阻的数学表达式，并由此计算了针叶树材管胞的气体渗透系数。

This feature of the spiral-flow has significant effects on the heat transfer enhancement and flow resistance.

这种旋转流动特性对内冷通道的强化传热和流阻特性具有很强的影响，与光滑通道相比，通道平均努塞尔数得到了明显的提高，但同时流动阻力也显著增加。

The results will facilitate analysis of the movement process and study of the flow resistance of the hydraulic cylinder seal structure.

该分析为水压缸步进动态过程理论建模以及水压缸密封结构泄漏流阻的研究提供了依据。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐