漳州新城大厦基坑降水工程实例分析

漳州新城大厦降水场地位于漳州盆地地下热水分布区边缘地带 ,地下水主要为松散岩类孔隙水 ,水位埋藏浅 ,水温高 ,基坑涌水量大 ,水文地质条件极其复杂 ,为了确保地下室在无地下水条件下施工 ,采取了深孔、大井径、短井距、大泵量的合理降水措施 ,取得了良好的降水效果 ,为安全施工提供了保证     

Quantification of annular flow in lined pipelines

This paper attempts to quantify the amount of flow within the annular space that could exist between a polymeric liner and a deteriorated host pipe. Inadequate fit of the liner within sewer line segments is likely to cause annular flow that will result in a higher flow rate within the wastewater collection system. The results of full-scale field tests performed by the authors on 12 pipelines lined with four different deformed/reformed or fold-and-form (DR/FF) and cured-in-place-pipe (CIPP) liner products indicated that gaps of different sizes existed in all of the tested pipelines. These gaps have resulted in variable annular flow in the tested pipelines. Based on the results of the full-scale tests, a mathematical relationship was established between the annular flow in a lined pipeline and the annular space. The relationship between the annular flow rate and the average annular gap size depends on the difference in head between the entry and exit points along the pipeline. In turn, the average annular gap size depends on many factors including tolerances and imperfections in the host pipe and liner, conditions of the host pipe and the quality of liner installation. A third-order polynomial equation was found to best describe the relationship between the annular flow and average gap size under high differential heads (up to 3.0 m or 10 ft); whereas, a logarithmic relationship fits best under low differential heads for wider range of annular gap sizes (up to 17.8 mm or 0.70 in.). Based on the results of the full-scale tests, this is believed to be more representative of typical liner installations.     

Inflow turbulence generation techniques for large eddy simulation of flow and dispersion around a model building in a turbulent atmospheric boundary layer

The present paper investigates the performance of various inflow turbulence generation techniques (ITGT) for large eddy simulation (LES) of flow and dispersion around a model building in a turbulent atmospheric boundary layer. Four different ITGT comprising 1 – no fluctuations, 2 – spectral method, 3 – vortex method and 4 – internal mapping, based on two basic methodologies (i.e. precursor and synthetic turbulence methods), are employed. These techniques are evaluated by considering their prediction accuracy, computational costs, complexity of implementation, inflow information required to operate and impacts on the flow downstream of the inlet, particularly in the wake region of the model building. Results indicate that the accuracy of LES predictions is greatly reliant on ITGT. It is shown that ITGT not only have significant effects on flow field vortical structures, but also influence frequency contents of velocity fluctuations, recirculation regions and plume shapes in the wake region.     

三山岛北部海域金矿区水文地质特征分析

通过开展水文地质测绘、水文地质钻探、钻孔综合水文测井及钻孔抽水试验,结合区域地质、水文和气象资料,基本查明了三山岛北部海域金矿区水文地质条件。区内主要含水岩层划分为第四系松散岩类孔隙含水层、花岗岩风化裂隙含水层和构造碎裂岩裂隙含水层,研究表明,矿坑充水直接因素为构造裂隙水,间接因素为风化裂隙水和第四系松散岩类孔隙水。采用比拟法、大井法和水平廊道法对矿坑涌水量进行了预测,除比拟法之外,其余2种方法是根据水文钻孔抽水试验结果计算的,抽水试验严格按照有关规范规程要求进行,试验数据可靠。矿坑涌水量预测结果显示:大井法和水平廊道法计算出的涌水量接近,而比拟法预测结果略微偏大,说明本次预测工作所采用方法和数据较为合理,间接证明渗透参数分析工作是合理的。     

A combined aeroelastic‐aeroacoustic model for wind turbine noise: verification and analysis of field measurements

In this paper, semi‐empirical engineering models for the three main wind turbine aerodynamic noise sources, namely, turbulent inflow, trailing edge and stall noise, are introduced. They are implemented into the in‐house aeroelastic code HAWC2 commonly used for wind turbine load calculations and design. The results of the combined aeroelastic and aeroacoustic model are compared with field noise measurements of a 500 kW wind turbine. Model and experimental data are in fairly good agreement in terms of noise levels and directivity. The combined model allows separating the various noise sources and highlights a number of mechanisms that are difficult to differentiate when only the overall noise from a wind turbine is measured. Copyright © 2017 John Wiley & Sons, Ltd.     

向心透平内部流动的数值分析及叶轮的改进设计

本文对一微型燃气轮机向心透平内部的三维流场进行了数值研究。在流场模拟的基础上对原结构的内部流场进行了分析探讨,指出原设计中可以改进的地方并成功的对叶轮进行了改进设计,使向心式透平效率提高了二点几个百分点。     

叶顶间隙对超临界二氧化碳向心透平性能的影响

为探究叶顶间隙对超临界二氧化碳向心透平机性能的影响,以某超临界二氧化碳向心透平为例,设置不同叶顶间隙,利用计算流体动力学(CFD)仿真软件进行数值模拟。结果表明:当径向间隙等于轴向间隙时,间隙尺寸在0.1~0.5 mm范围内,叶顶间隙与叶轮出口叶高的比值每增大1%,总-静效率降低1.07%左右。当径向间隙不等于轴向间隙时,轴向间隙每增大1%,总-静效率降低0.146%左右,径向间隙每增大1%,总-静效率大约降低0.362%;径向间隙对于透平性能的影响远大于轴向间隙,叶顶间隙在0.1~0.5 mm范围内时,径向间隙对总-静效率的影响约为轴向间隙的2倍。     

龙门煤矿矿井涌水量预测及水文地质类型评价

龙门煤矿矿区位于河南省偃龙煤田西段,属佛光（偃师市）—龙门（洛阳市）水文地质亚单元的一部分。根据地层厚度、岩性、富水性及渗透性等特征,将矿区地层划分为6个含水层和5个隔水层;矿井充水条件主要分为充水水源、充水通道和影响充水强度因素;采用“大井法”和“比拟法”对矿井涌水量进行预测,得出:未来生产矿井的最大涌水量按正常涌水量的1.13倍计算。根据矿井水文地质类型划分依据判断,洛阳龙门煤业有限公司龙门煤矿水文地质类型划分为极复杂类型。     

中奥陶统顶部地层富水性规律研究

矿井11号煤层最低开采标高+230 m,井田中奥陶统灰岩含水层水位标高+360 m,煤层开采存在奥灰水带压开采问题,而11号煤层底板至中奥陶统顶面隔水层平均厚度20 m,因而中奥陶统顶部峰峰组一段和上马家沟组三段地层的富水性,以及是否可以作为相对隔层利用,对煤层承压开采至关重要。通过水文钻探、放水试验和压水试验,分析了中奥陶统顶部地层的岩性特征、富水性特征、渗透性特征。综合试验结果表明,中奥陶统顶部地层主要以泥质白云岩、泥质灰岩为主,顶部18 m地层隔水性能良好,揭露大部层段属弱富水性含水层,透水率小于10 Lu,属极微透水至弱透水,为煤层承水压开采奠定有利的地质条件。     

三峡水库正常运行期入库流量计算方案分析

总结了三峡水库正常运行期的坝前水位一般控制规律,阐述了三峡库区动库容对其入库流量计算的影响。根据三峡水库的调节性能和坝前水位控制规律,将水库的坝前蓄水状态分为3个等级,并分析了各蓄水等级下的入库流量最佳计算方案,有效解决了入库流量的锯齿跳变问题,符合实际。