复杂冲沙廊道系统最优运行方式的数值模拟研究

电站取水口复杂冲沙廊道系统的冲沙孔孔前漏斗范围往往随冲沙流量增加而增大,但相应地,冲沙孔与廊道连接过渡段的压力则迅速减小,并出现较大负压,简单的调度运行方式很难使这种复杂冲沙廊道的压力特性及冲沙漏斗范围均达到较佳,必须进行调度方式的优化研究才能达到此目的。本文采用数值模拟的方法研究了大渡河龙头石水电站取水口冲沙廊道系统的最优运行方式,结果表明,通过改变冲沙孔运行方式,冲沙漏斗范围及冲沙系统压力特性这两个目标可同时达到较优的效果,对类似的取水口冲沙系统运行方式拟定具有重要工程价值和科学意义。     

基于RVA法的河流生态需水量研究

以河流生态水文变化的指标体系（Indicator of Hydrologic Alteration,IHA）为基础,立足整体河流水文情势的流量谱系,采用变异性范围法（Range of Variability Approach,RVA）,进行基于长系列历史流量资料的河流生态需水量估算,并以山西省5条较大河流的生态敏感断面为对象进行研究。结果表明,利用本方法估算的结果是合理的,可为河流生态需水量的估算和水资源的可持续开发利用提供科学依据。     

SAPTIS：结构多场仿真与非线性分析软件 开发及应用（之一）

介绍大型结构多场仿真与非线性分析软件SAPTIS,包括软件中所采用的单元类型、方程求解方法、大坝全过程仿真的开挖浇筑模拟方法、水化热模型、通水冷却模型、温度边界条件、弹性模量模型、徐变度模型、自生体积变形以及掺MgO混凝土特性等,还给出了分析结果表达方式。该软件已成功应用于三峡、二滩、龙滩、小湾、溪洛渡、锦屏、丹江口等四十余个大中型水利水电工程的混凝土坝和其他结构温度场、应力场仿真分析、温控防裂和大坝真实工作性态研究,取得了良好的经济效益。应用成果表明,SAPTIS采用的计算模型能正确反映混凝土材料的热学特性、混凝土结构的应力和变形特性,具有计算速度快、计算规模大、结果精度高等优点。     

基于物联网的灌浆监测系统的 应用研究

物联网是目前飞速发展的新一代信息技术。结合物联网的优势及特点,本文对其在灌浆施工管理中的应用进行了研究;即采用多种无线技术构建了无线灌浆数据监测系统。该系统可将多台灌浆记录仪采集到的灌浆数据发送到中央服务器,形成灌浆施工物联,从而降低布线成本,简化工程设计,实现灌浆记录仪的全面监测,直观有效地进行灌浆施工管理,为灌浆行业的蓬勃发展提供了技术保障。     

灌区闸门智能调度系统性能评价

针对都江堰灌区渠首闸门智能调度系统模型,利用最小方差的计算原理,定义模型性能判定指标。根据当前需水流量及相对应的闸门开度值,计算当前闸门系统模型的性能判定指标值,并对所得结果进行分析。该方法可以及时有效地对当前使用的闸门系统模型进行监控与修正,同时也可以应用到数据分析中,对预测模式的应用进行评估。     

简析山东莱阳市风电整体开发方案

∶根据国家能源局和山东省发改委关于规范风电建设的要求,按照莱阳市政府的要求,以及为了更加规范合理的开发莱阳市的风电资源,根据现有测风资料,测算出了莱阳市可以开发风电的总容量,并依据风资源、接入条件等列出了项目开发顺序,以供莱阳市政府和项目开发之参考。     

一种Godunov算法及其在非平底流污染物传输中的应用

采用和谐的加权平均通量(Weighted Average Flux,简称WAF)算法,研究了浅水波方程的间断解及污染物传输问题。该算法采用WAF格式和HLLC Riemann求解器近似单元边界数值通量,中心差分格式离散地形源项,然后理论上证明了该算法是和谐的。最后利用WAF算法对非平底地形上浅水波间断解及污染物传输问题进行数值计算,精确地捕捉到了间断解和污染物运动过程,结果表明该算法满足守恒性,具有高分辨率、无振荡及捕捉污染物运动边界的能力。     

Application of signal processing techniques to the detection of tip vortex cavitation noise in marine propeller

The tip vortex cavitation and its relevant noise has been the subject of extensive researches up to now. In most cases of experimental approaches, the accurate and objective decision of cavitation inception is primary, which is the main topic of this paper. Although the conventional power spectrum is normally adopted as a signal processing tool for the analysis of cavitation noise, a faithful exploration cannot be made especially for the cavitation inception. Alternatively, the periodic occurrence of bursting noise induced from tip vortex cavitation gives a diagnostic proof that the repeating frequency of the bursting contents can be exploited as an indication of the inception. This study, hence, employed the Short-Time Fourier Transform (STFT) analysis and the Detection of Envelope Modulation On Noise (DEMON) spectrum analysis, both which are appropriate for finding such a repeating frequency. Through the acoustical measurement in a water tunnel, the two signal processing techniques show a satisfactory result in detecting the inception of tip vortex cavitation.     

Evaluation of suspended load transport rate using transport formulas and artificial neural network models （Case study： Chelchay Catchment）＊

Accurate estimation of sediment load or transport rate is very important to a wide range of water resources projects. This study was undertaken to determine the most appropriate model to predict suspended load in the Chelchay Watershed, northeast of Iran. In total, 59 data series were collected from four gravel bed-rivers and a sand bed river and two depth integrating suspended load samplers to evaluate nine suspended load formulas and feed forward backpropagation Artificial Neural Network (ANN) structures. Although the Chang formula with higher correlation coefficient (r = 0.69) and lower Root Mean Square Error (RMSE = 0.013) is the best suspended load predictor among the nine studied formulas, the ANN models significantly outperform traditional suspended load formulas and show their superior performance for all statistical parameters. Among different ANN structures two models including 4 inputs, 4 hidden and one output neurons, and 4 inputs, 4 and one hidden and one output neurons provide the best simulation with the RMSE values of 0.0009 and 0.001, respectively.     

Time stepping in discontinuous Galerkin method

The time discretization in the Discontinuous Galerkin (DG) scheme has been traditionally based on the Total Variation Diminishing (TVD) second-order Runge-Kutta (RK2) scheme. Computational efficiency and accuracy with the Euler Forward (EF) and the TVD second-order RK2 time stepping schemes in the DG method are investigated in this work. Numerical tests are conducted with the scalar Burgers equation, 1-D and 2-D shallow water flow equations. The maximum Courant number or time step size required for stability for the EF scheme and RK2 scheme with different slope limiters are compared. Numerical results show that the slope limiters affect the stability requirement in the DG method. The RK2 scheme is generally more diffusive than the EF scheme, and the RK2 scheme allows larger time step sizes. The EF scheme is found to be more efficient and accurate than the RK2 scheme in the DG method in computation.