With this method , the feasibility of project can be decided preliminarily . 3 . one - dimensional hydrodynamic model is built , in which implicit difference format ( preismann discretization scheme ) and " three steps method " of one - dimensional unsteady flow model is used , hydraulic calculation is done for water diversion and flow strengthen in tidal networks and the method is enhanced in which the precision is improved greatly 建立一维水动力学模型，利用四点隐式差分格式( preismann格式)和一维河网非恒定流模型的三级解法，对感潮河网的引水增流工程进行了水力计算并对计算方法进行了改进，大大地提高了计算的精度。
Combined with the construction programming of no . 3 lock , further studies on the flow pattern at various locks are undertaken . to the actual conditions of siyang locks and taking various effects into consideration , engineering measures which are expected to ameliorate the pattern of flow at lower lock approach are propose 在此基础上，结合泗阳三线船闸的建设规划，进一步对各线船闸水流特征进行了计算和试验，针对泗阳船闸的具体情况综合考虑多种因素，提出了改善下游引航道非恒定流的工程措施，获得了满意的结果。
First , the difference between the stm and utm is compared and analyzed . the results show that it can accurately simulate the unsteady flow process of piston wind and the pollutant distribution in tunnel after train left the tunnel , can analyze and calculate the good effect of inertial action of piston wind if using utm 文中首先分析和比较了传统隧道通风设计所采用的恒定流理论与非恒定流理论的差别，表明运用非恒定流理论不仅更能准确模拟隧道内活塞风的非恒定流动过程，而且能模拟列车通过隧道过程中隧道内污染物浓度的分布，同时还能考虑利用隧道内气流(活塞风)惯性作用促进隧道通风，节约通风能耗。
It was specially pointed out that , when the tail water is constant maximum tide , the computed flood surface is higher than that of nonsteady current , so there is some safety superelevation . underestimation of the roughness will make downward bias to compute along - river surface and bring hidden trouble for flood control . to improve the section can decrease the water level or offset the water rise for increase of floodplains " roughness , but it need much engineering works 特别提出，按照恒定流计算出来的设计水位比非恒定水位具有一定的安全储备；而对于滩地糙率的低估又会造成设计水位的偏低，给防洪工作带来隐患；如果利用改进断面形式来降低水位或弥补糙率增加带来的水位抬高，需要较大的工程量，所以平时应注意滩面的减糙管理工作。
In this thesis work , a 1 - d hydraulic transient model and a 2 - d compressible flow model with the large eddy simulation approach have been applied to analyse the hydrodynamic process of the unsteady separated flow . prototype observation data of gezhouba shiplock no . 3 has been used to verify the computational results . it has been found that two different types of flow regime - stably - varying and strongly - oscillating regimes - could occur in the radial gate tunnel 本文采取将一维非恒定流模型与二维可压缩流一大涡模拟模型相结合的方法，分析了急变分离流的水动力学特性，并利用葛洲坝三号船闸的原型观测资料验证了数值模型的可靠性，发现阀门段存在平稳变化型和剧烈振荡型两种不同的流态，并详细计算、分析了它们的流动特征
Then a one - dimensional unsteady incompressible flow with moving pollutant source model was proposed . the continuity equation , momentum equation and convection - diffusion equation were discredited using finite volume scheme . thus a software for predicting the air velocity and pollutant in railway double track tunnels was developed 接着，根据双线铁路隧道运营通风的特点，建立了一维不可压缩非恒定流和流动污染源的物理模型以及山相应的连续性方程、动量方程和对流扩散方程构成的数学模型；在此基础上，利用数值计算方法，编制了一套双线铁路隧道运营通风的数值计算程序。
Based on the river regime of tgp dam area and the arrangement of upper and lower access channels , the experimental research on the influence of such unsteady flow on the navigation , the evaluation of navigable conditions under the unsteady flow and the study of corresponding improvement measures are presented in this paper 本文结合坝区河势特点及上下游引航道布置，试验研究了大坝泄洪及船闸充泄水非恒定流对上、下引航道通航影响，同时进行了非恒定流通航条件评价及改善措施研究。
Except for research on the unsteady flow at lower lock approach in siyang , jiangsu province by physical model , a two - dimensional numerical model is developed to explore the alternate research method in this paper . through studying the project using physical model and numerical model simultaneously , the governing equations , numerical algorithm and the computation accuracy of the numerical model are analyzed . comparison between computed results and experimental data gives that computed results is well agree with measured data under several water level cases , which indicates that the numerical model is valid and reliable 通过数学模型和物理模型的同步研究，对数学模型的控制方程、数值计算方法以及数值模拟的精度与物理模型试验进行了比较分析，同实测资料验证的结果表明：该数学模型与物理模型一样在不同的水位组合，不同的运行工况条件下都能正确地模拟下游引航道非恒定流的实际水力情况，模型计算结果与实测资料十分吻合，说明建立的数学模型是合理的，结果是可靠的，可以利用该数学模型进行船闸下游引航道非恒定流特性的研究。
