水力直径

水力直径作为当量直径的适用范围、缺欠与修正

The applicable range , defect and correction of equivalent diameter used hydraulic diameter

流量系数随矩形节流槽截面深宽比增大而增大，并随截面水力直径增大而有所增大。

The Cd increased with the depth-width ratio of notch cross-section , and increased to some extent with the hydraulic diameter of notch cross-section .

本文进行了对比性的实验，以研究相变材料微胶囊（MEPCM）-水悬浮液在水力直径为2.71mm的矩形小通道内的层流流动传热性能。

A series of comparative experiments was conducted to investigate the laminar flow heat transfer characteristics with microencapsulated phase change material ( MEPCM ) suspensions in water flowing through rectangular mini-channels with a hydraulic diameter of 2.71 mm .

这2种不同结构的硅基微通道的水力直径均为155.3微米，且具有可比性。

Both of the two types of microchannels have the same hydraulic diameters of 155.3 microns , and have comparability .

截面形状相同时，水力直径较大的热管热阻值低于水力直径较小的热管；

For the same PHP , the thermal resistance of PHP with bigger hydraulic diameter is lower than that with small hydraulic diameter .

实验表明，当微通道水力直径为381μm时，宏观理论公式已不适用于微通道摩阻及其换热的计算。

It is shown that classical macroscopic formulas are not applicable for calculating friction resistance and heat exchange coefficients when channel hydraulic diameter is 381 μ m.

微通道热沉是制作在硅芯片基底背面的微细通道，其水力直径范围为10~1000μm。

Microchannel heat sinks are minute channels fabricated onto the back of the thin silicon chip substrate with hydraulic diameter ranging from 10 to 103 μ m.

关键技术包括：（1）适当的延长油浴加热时间，获得水力直径小且分布窄的氢氧化铝胶粒；

The key technology includes : ( 1 ) prolonged heating time to obtain Al ( OH ) _3 particles with small size and narrow hydrodynamic diameter distribution ;

因该旋流管的水力直径较大，切向速度的总体水平较低，由此对了离特性带来不利影响。

Since this geometrical configuration has a large hydraulic diameter , all the tangential velocities are kept in a low level , so the separation performance is not good enough .

虚糙率的成因分析对1倍和2倍隧道水力直径开口缓冲结构的不同开口形式、开口位置及开口率进行了细致研究。

Analysis of the Cause Forming Imaginary Roughness A detailed study has been made on the different vent pattern , different vent position and different vent ratio of the tunnel with one and double hydraulic radius .

对带角断面通道紊流，用水力直径作为当量直径来计算壁平均摩擦系数将带来偏差。

It is recognized that for turbulent flow inside a duct of angular cross section , delation will take place if the flow diameter is used as the equivalent diameter to calculate the mean friction coefficient of the duct wall .

随着换热装置流体通道水力直径的逐步减小，系统内流体的对流换热系数明显提高，其换热能力明显增加，但流体的流动阻力也将显著增加。

As with the reducing gradually of the hydraulic diameters of the heat exchanger fluid channels , the convection heat coefficient of fluid and heat transfer capacities of the systems are obviously improved . However , the flow resistance increases significantly .

从流动阻力与换热机理的角度给出水力直径的适用范围与误差，指出其误差大小完全取决于通道边壁的曲折程度和Re数的大小。

The applicable range and the error of the hydraulic diameter are represented according to the mechanism of flow resistance and heat transfer . The error is dependent on : a , the winding degree of the wall of channel , b , the Reynolds number .

采用加热当量直径为定性尺寸要比采用水力当量直径更为合理。

Secondly , using heat diameter is more reasonable than using hydraulic diameter .