山西省无资料地区水文计算方法与应用研究通过鉴定

<正>2012年12月25日,由山西省水文水资源勘测局编制的山西省无资料地区水文计算方法与应用研究通过专家鉴定。与会专家认为:该项目首次提出了水文下垫面科学分类方法,并编制了山西省水文下垫面地类图;系统建立了一整套无资料地区水文计算模型和方法,构建了幂函数地表径流计算模型和基流计算模型,首次提出了无资料地区偏差系数的计算公式,改进了无资料地区年径流变差系数计算公式,提高了工程水文计算的可靠性;研究提出     

定期冲洗式沉沙池泥沙沉降特性分析

以黄河东城提水工程首部的定期冲洗式沉沙池为研究对象,应用一维超饱和输沙法计算了泥沙的沉降历时,分析了泥沙恢复饱和系数、极限吸出高度、出池含沙量等泥沙沉降特性。结果表明:①泥沙恢复饱和系数随泥沙粒径的增大呈指数递减趋势,工作段上游泥沙恢复饱和系数随沉降历时呈指数递减趋势,工作段下游恢复饱和系数随沉降历时呈线性减小趋势;②随着沉沙池的运行,出池泥沙粒径逐渐变大,淤积泥沙粒径则逐渐变小;③在沉沙池运行期内,溢流堰极限吸出高度随沉降历时呈线性递减趋势;④溢流堰前分组含沙量参考点的相对水深均小于0.5;⑤在0～0.500 mm泥沙粒径范围内,出池平均含沙量参考点的相对水深与泥沙粒径呈对数递增。     

基于集对分析的土石坝安全风险评价

针对土石坝安全评价中存在的不确定性因素,建立了基于集对分析理论的土石坝安全评价模型。由工程质量、运行管理、现场检查、防洪安全、大坝整体稳定、变形裂缝、渗流安全、抗震安全、金属结构组成土石坝安全评价指标体系,采用基于加速遗传算法的层次分析法求得指标权重,并经过单指标联系数、综合联系数和相对隶属度等的计算,对某土石坝的安全等级进行综合评价。结果表明,集对分析方法运用在土石坝的安全评价中是可行而有效的。     

Bubble hydrodynamic influence on oxygen transfer rate at presence of cationic and anionic surfactants in electroflotation proces

In this work, the effects of the presence of surfactants in the liquid phase and the hydrodynamic regime of the bubble flow on the oxygen transfer rate were investigated in an electroflotation process in batch mode. The volumetric mass transfer coefficient KLα and the oxygenation capacity were evaluated to improve the performances of the electroflotation process in terms of oxygenation. In order to evaluate the liquid-side mass transfer coefficient KLα the volumetric mass transfer coefficient KLα was dissociated into KL and the specific interracial area （a） since the last one was obtained from the gas hold-up and the bubble diameter. The effect of Reynolds number which define the hydrodynamic of the bubble flow has been also studied. Models of KLa and KL have been established to show the effects of the hydrodynamic parameters and liquid phase characteristics on the oxygen transfer rate.     

调水工程输水渠道堰闸流量计算方法探讨

调水工程输水渠道堰闸流量计算方法的准确性是运行调度数字化、信息化的关键水力条件。传统的堰闸流量计算方法是先进行孔流、堰流判别,再根据相应的经验公式进行计算,其孔、堰流判断条件为闸门的相对开度e/H。经试验研究及理论分析论证认为:传统计算公式中以e/H=0.65作为宽顶堰孔流与堰流的判断条件,仅适用于自由出流状态。调水工程输水渠道堰闸工程正常运行条件一般为大淹没孔流,传统方法计算流量误差较大。通过系列模型试验数据的拟合,提出了特定条件下调水工程堰闸流量计算方法。     

李溪拦河闸坝改造工程的消力池设计

流溪河是典型的山区性河流,建有多座梯级拦河闸坝。由于河床下切严重,上下游水位差较大,部分拦河闸坝的消能防冲问题较为突出。详细介绍二级消力池在李溪拦河坝改造中的设计应用,结合水工模型试验的成果进行分析,并与改造后实际过流对比,提出山区性泄洪闸消能工选取中应重点考虑的因素。     

洮儿河冲洪积扇河道 渠系渗漏补给系数的分析

河道渗漏补给系数、渠系渗漏补给系数是水资源量分析评价必不可少的参数。文中根据近年实测洮儿河、蛟流河各水文站、"引察入向"各断面的水文资料,分析得出洮儿河冲洪积河道渗漏补给系数、渠系渗漏补给系数,为了今后作洮儿河流域水资源分析评价,提供科学依据。     

风险排序及其在病险水库除险加固工程中的应用

鉴于我国病险水库较多、除险资金有限,结合工程实际情况,综合考虑水行政主管部门对水库的管理,从洪灾风险出发,介绍了基于洪灾风险的排序方法,分析了溃坝后果综合评价函数的子因素：生命损失、经济损失、社会与环境影响的权重系数和严重程度系数,将该方法应用于工程并得到了与实际较为吻合的数据,为我国今后病险水库除险加固排序决策提供参考依据。     

Heat transfer characteristics in micro-fin tube equipped with double twisted tapes： Effect of twisted tape and micro-fin tube arrangements

An experimental study was carried out to investigate the influence of double twisted-tape inserts (DTs) in micro-fin tubes (MFs) on heat transfer, friction factor and thermal performance factor characteristics of the compound devices in the following configurations: (1) twisted tapes acted in the same direction (for co-swirl) while MF and twisted tapes acted in the same (parallel) direction (MF-CoDTs:P), (2) twisted tapes acted in the same direction (for co-swirl) while micro-fin tube and twisted tapes acted in opposite directions (MF-CoDTs:O) and (3) twisted tapes acted in opposite directions for counter swirl (MF-CDTs). The MF alone and the MF equipped with a single twisted tape in parallel/opposite arrangement were also considered for comparison. The experiments were conducted for the flows with the Reynolds numbers between 5 650 and 17 000, under uniform heat flux condition. The experimental results indicate that MF-CDTs induce stronger swirl/turbulence flow, resulting in higher heat transfer rate, friction factor and thermal performance factor than other combined devices. The thermal performance factors associated with the use of MF-CDTs were found to be higher than those associated with the uses of MF-CoDTs:P, MF-CoDTs:O and MF alone up to 9.3%, 6.5% and 56.4%, respectively. The empirical correlations developed using the present experimental data for the Nusselt number, friction factor and thermal performance factor are also reported.     

郝家店水文站宽顶堰测流系数分析

对郝家店水文站宽顶堰流量系数进行了分析,并对宽顶堰流量系数所推求的流量与常规方法推求的流量测验精度作了对比分析评价,从而验证了宽顶堰流量系数采用的合理性。