A Pipeline Testing Facility for the Examination of Pipe-Wall Deposits and Red-Water Events in Drinking Water

Field surveys of Thames Water's distribution mains found the occurrence of 'red water' to be highly variable and localized. To model the many inter-related factors identified in the field, a controlled pipeline-testing facility was required to simulate conditions in a 'live' network, but on a pilot-scale. This was achieved by incorporating a specialized red-water testing facility into an existing experimental pipeline.
This paper describes the hydraulic and material design features, including the addition of a 'dead-end' section operated on a stagnation and flow regime, quantified using computational fluid dynamics. Following commissioning, the facility has provided detailed, time-sequenced observations on corrosion-deposit development and red-water generation under different hydraulic regimes.     

太阳吸收涂层与真空集热管的热性能

全玻璃真空集热管的热性能可用空晒温度，闷晒试验与平均热损系数表示。制备的五种多层铝－氮／铝吸收涂层，具有相近的高太阳吸收率，而法向发射率εｎ在０．１４－０．０５（８０℃）范围内。     

直埋水平转角管段驻点位置的影响因素

探讨了两侧为活动端的直管段及一侧活动端为弯头,而另一侧活动端为波纹管补偿器的水平转角管段驻点位置的计算。影响水平转角管段驻点位置的主要因素为波纹管补偿器设置位置、弯头角度。     

全玻璃真空太阳集热管光—热性能

从能量平衡议程导出全玻璃真空太阳集热管的3个光－热性能参数,即热损系数UTL、闷晒太阳曝辐量H和空晒性能参数Y与真空热管理的罩管玻璃的太阳透射比τ、选择性吸收表面的太阳吸收比a、发射比ε、和集热管内的气体压强p,太阳辐照度、环境温度和真空太阳集热管的几何尺寸等函数关系。理论计算的真空太阳集热管的3个热性能参数与实验的结果比较一致。上述全玻璃真空太阳集热管的光－热性能参数已经被国家标准《全玻璃真空太阳集热管》（GB／T17049－1997）采用。     

基于差分进化算法的多维传感器动态解耦方法

差分进化算法(differential evolution algorithm,DE)是近年来比较流行的进化算法,被广泛应用于复杂的优化问题中.但常规的差分进化算法存在停滞现象,容易使算法收敛停止,鉴于此本文提出一种改进的差分进化算法,防止了停滞现象也加快了收敛速率并使算法能收敛到全局最优.基于小生境差分进化算法,提出...     

一种基于动态边界的粒子群优化算法

2007年提出的标准粒子群优化算法(PSO-2007)在进化的后期容易出现停滞现象而导致早熟收敛,为此本文提出了一种基于动态边界的粒子群优化算法(DBPSO).该算法根据停滞期粒子运动的特点,将边界动态调整策略引入到PSO-2007中,通过跟踪粒子飞行位置的分布动态调整搜索空间的边界,引导粒子在更有效的区域内进行搜索,从而减轻早熟收敛,提高收敛精度.典型测试函数的求解实验结果表明DBPSO是可行而有效的.     

液压注塑机停滞问题的研究和改进

通过动态测量和分析 ,查出造成液压注塑机停滞问题的原因 ,为此 ,对液压回路进行了改进。     

Transport of thermal energy in the magnetohydrodynamic oblique stagnation point flow in a hybrid nanofluid with nanoparticle shape effect

In the present paper, the augmented heat characteristics of a hybrid nanofluid which is a blend of Al₂O₃ (alumina) and Ag (silver) in the host hybrid fluid (C₂H₆O₂-H₂O) (50%–50%) impinging obliquely on an elastic surface with magnetic lines of force are investigated. The properties of the nanofluid are assessed through the computational solutions established with the aid of the popular Runge–Kutta–Fehlberg fifth-order (RKF 5) numerical technique. Outputs of the analysis reveal that the rate of thermal energy transport in the hybrid (mono) nanofluid is enhanced by 11.5% (5.8%) by using blade-shaped nanoparticles in comparison to that of the spherical particles. Stream contours of both nanofluids are inclined to the left (right) of the stagnation-point for positive (negative) values of the stagnation flow parameter.     

大间距两不对称喷嘴对置撞击流驻点偏移规律

采用热线风速仪对大喷嘴间距下两不对称喷嘴形成的对置撞击流的轴线速度分布和驻点偏移规律进行了实验研究.研究结果表明,在大喷嘴间距下,两股射流在发生碰撞前,射流已经进入了充分发展区,当两喷嘴出口动量相等时,驻点位于两个喷嘴轴线中心;在撞击区中,两股射流关于撞击面是对称的.轴线上撞击流驻点受两喷嘴动量比的控制,随着动量比偏离1撞击流驻点向动量小的一侧喷嘴移动,两喷嘴出口动量差别越大,驻点偏离中心距离越大.得到了一个描述大喷嘴间距下驻点偏移的公式,拟合结果与实验结果的平均相对误差为10%.