文章分析了水泵在使用中的能耗现状及相应的节能方法。在此基础上,以梯级泵站水泵消耗功率最小为目标函数,阐述了水泵切削技术在泵站节能中的应用原理。文章采用Visual Basic6.0开发了具有一定通用性的切削量优化软件,并给出了具体算例,从而达到快速实现水泵切削量的自动优化,并在生产实践中达到了准确调节的目的。

The turbulent flow in open channel with smooth surface and artificially made rough surface is tested,in which the longitudinal mean-flow velocity and fluctuated mean flow velocity of the turbulent flow on smooth,transitional and rough surfaces with various water depths are measured by laser Doppler velocimeter(LDV).Based on the measured data,the effect from the artificial roughness on the turbulence intensity of the flow is analyzed,and then the developing and changing laws of the turbulence intensity for the smooth,transitional and rough surfaces of open channel are obtained.

利用激光测速仪,对壁面自水力粗糙面突减至水力过渡面时过渡段内的明渠紊流进行了试验研究,测量了糙率突减不同水深情况下明渠紊流的纵向时均流速和脉动流速。通过实测资料,分析水深和糙率改变后内边界层发展变化规律、粗糙度及水深对内边界层厚度的影响以及糙率突减后从一种均匀紊流到形成新的充分发展紊流所需要的纵向长度。

This paper makes experimental study on the turbulence under roughness coefficient mutation on bottom wall of open channel,measures the mean velocity and fluctuating velocity of turbulence at different water depth by using LDV,and based on a lot of experimental results,analyzes the evolving rules and thickness of boundary layer at different water depth and with different roughness coefficient,and studies on the necessary longitudinal length when flow changes from homogeneous flow to new turbulence.

带式运输机被广泛应用在煤炭、港口、电厂、钢铁企业等生产线上,在现代集散控制系统当中PLC已成为一种重要的基本控制单元。文章主要介绍PLC技术在带式输送机中的控制应用,并给出了控制梯形图。

The turbulent flow in open channel is tested with laser-Doppler anemometer, in which the longitudinal time average velocity and fluctuating velocity of turbulent flow in open channel under the conditions of the sudden changes of roughnesses at different water depths are measured. Based on the measured data, the change of the friction velocity of turbulent flow and the characteristics of the wall shear stress under different sudden roughnesses and different water depths are analyzed herein.

文章根据我国无砂透水性混凝土开发和应用的现状,对无砂透水性混凝土抗压强度、透水性进行了试验研究,分析了混凝土抗压强度和透水系数与水灰比、骨料粒径的关系,提出了强度高达C50,透水系数为2.89mm/s的透水性混凝体最优配比方案。

By testing open canal turbulent flow as wall surface coefficient of roughness anticlimax using laser Doppler anemometer,author has measured open canal portrait average flow velocity per hour and fluctuating velocity as various water depth coefficient of roughness anticlimax and has gained open canal turbulent distribution characteristic of average flow velocity per hour after wall surface coefficient of roughness reduction and development & variety of intensity of turbulence by field data analysis roughness anticlimax on open canal turbulent flow influence.

Three methods of turbulent numerical simulation are summarized in paper:Direct Numerical Simulation(DNS),Reynolds Averaged Navier-Stokes(RANS) and Large Eddy Simulation(LES).Their characteristics and applicability are analyzed and compared mainly in basic conceptions and theories according to the researchers studies in the last years.The conclusions will be helpful for study of turbulence.The methods of turbulent numerical simulation are still being groped now, so the research directions that will obtain salient developments of turbulence in the future are given in the end.

文章介绍了Motion Logic设计的步进电机控制器,该系统能很好地兼顾步进电机的高低速性能,使电机具有高速运行时输出力矩大、低速运行时细分定位精度和平稳性高,驱动器发热量小、噪音低、振动小等特点,电机能在整个频率段平稳运行。

The structure and basic theory of automatic inclinometer system was presented,which take advanced quartz servo-accelerometer as sense organ.Examples testify that it can require need measure precision.The system has many merits,such as high measure precision,better anti-jamming character,light mass,low power cost and it fits fieldwork for power supply by battery.It can't affect construct as measure and can't be affected by weather.Also it is operated so convenient,spry and agile.