运用实验检测手段指导洗涤污水处理

某洗涤车间采用洗衣膏等进行列车卧具、餐车台布等物品的洗涤,在对其尾水进行日常监督性监测过程中发现主要污染因子pH、SS、COD、LAS均能够达到《水污染物排放标准》排放要求,而惟独油异常超标。为查明原因,我站进行了连续跟踪监测,运用实验检测手段化验分析,用检测数据指导并完善洗涤污水处理工艺,确保洗涤污水达标排放。     

全方向推进器非定常水动力性能的面元预报方法

研究了全方向推进器非定常水动力性能的面元预报方法,基于螺旋桨面元法建立了全方向推进器的非定常水动力性能计算的数学模型,对全方向推进器的非定常水动力性能进行了数值预报。采用了关于扰动速度势的基本积分微分方程,并采用双曲面元以消除面元间的缝隙。用Newton-Raphson迭代过程在桨叶随边满足压力Kutta条件。在计算面元的影响系数时,应用Morino导出的解析计算公式加快了数值计算的速度。为避免数值求导中的奇异性,用Yanagizawa方法求得物体表面上的速度分布。本文计算结果与日本水池模型试验结果、升力线方法计算结果及升力面方法计算结果进行了对比。     

基于红外图像的夜间驾驶员疲劳检测系统设计

当前来说由于疲劳驾驶而引发的交通事故越来越多,而夜间是疲劳驾驶的高发时段,由于这种原因,文章设计了适用于在夜间监测驾驶员是否处于疲劳状态的系统。利用OPENCV软件对得到的红外图像进行人脸的检测与识别,得到人脸的红外图像,针对得到的人脸红外图像进行灰度化和二值化的处理,设定一个阈值根据二值化后像素的个数判断驾驶员是否处于疲劳状态,如果处于疲劳状态的情况下,系统就会报警提醒驾驶员注意采取措施。如果驾驶员并不处于驾驶疲劳的状态,那么监测系统将继续检测。     

基于混合迭代法的二维水翼空泡性能分析(英文)

In order to study cavitation characteristics of a 2-D hydrofoil, the method that combines nonlinear cavitation model and mixed-iteration is used to predict and analyze the cavitation performance of hydrofoils. The cavitation elements are nonlinearly disposed based on the Green formula and perturbation potential panel method. At the same time, the method that combines cavity shape for fixed cavity length (CSCL) iteration and cavity shape for fixed cavitation number (CSCN) iteration is used to work out the thickness and length of hydrofoil cavitations. Through analysis of calculation results, it can be concluded that the jump of pressure and velocity potentially exist between cavitation end area and non-cavitations area on suction surface when cavitation occurs on hydrofoil. In certain angles of attack, the cavitation number has a negative impact on the length of cavitations. And under the same angle of attack and cavitation number, the bigger the thickness of the hydrofoil, the shorter the cavitations length.     

板桩防波堤在海外浅海区域工程中的应用

浅海区域波浪、水流等自然条件相对较好,采用常规实体斜坡式防波堤投资较高,可考虑采用直立式板桩防波堤结构进行替换,节约工程投资。基于实际工程项目,采用美标计算板桩防波堤前波浪力,并通过物理模型试验对波浪力进行验证;最后通过岩土有限元软件PLAXIS分析板桩防波堤各构件内力及整体位移。分析结果表明：1）板桩防波堤各构件内力较小,可采用相应型号的预制构件作为板桩防波堤主体结构;2）板桩防波堤整体位移可控;3）在浅海区域,采用板桩防波堤结构合理可行。     

基于无限元方法预报非均匀流中螺旋桨的流噪声

为了系统地研究非均匀流场中螺旋桨流噪声的特点,采用CFD与声学无限元方法结合的方式,对螺旋桨的频域噪声进行数值预报。通过采用大涡模拟方法对非均匀流场中的螺旋桨水动力性能进行计算,然后运用ACTRAN软件的声学无限元方法,对螺旋桨的无空泡噪声进行数值模拟,并对特征点进行频域分析。流场计算结果显示:非定常计算得到的螺旋桨水动力系数与试验值吻合良好,LES模拟得到的流场初值是可信的;通过分析噪声分布云图及特征点频谱曲线得出:非均匀流场中螺旋桨的辐射噪声主要集中在低频段,且该频段的噪声主要由偶极子组成,同时噪声衰减速度随频率增大而减小,螺旋桨轴向声压级高于径向两侧,验证了计算结果的可靠性,为螺旋桨的水下噪声预报提供了一种新的方法。     

舵几何参数对桨舵系统水动力性能的分析(英文)

In order to study the effects of geometric parameters of the rudder on the hydrodynamic performance of the propeller-rudder system,the surface panel method is used to build the numerical model of the steady interaction between the propeller and rudder to analyze the relevant factors.The interaction between the propeller and rudder is considered through the induced velocities,which are circumferentially averaged,so the unsteady problem is translated to steady state.An iterative calculation method is used until the hydrodynamic performance converges.Firstly,the hydrodynamic performance of the chosen propeller-rudder system is calculated,and the comparison between the calculated results and the experimental data indicates that the calculation program is reliable.Then,the variable parameters of rudder are investigated,and the calculation results show that the propeller-rudder spacing has a negative relationship with the efficiency of the propeller-rudder system,and the rudder span has an optimal match range with the propeller diameter.Futhermore,the rudder chord and thickness both have a positive correlation with the hydrodynamic performance of the propeller-rudder system.