【作者】 牧振伟；

【导师】 周著； 邱秀云； 侯杰；

【作者基本信息】 新疆农业大学 ， 水力学及河流动力学， 2000， 硕士

【摘要】 本文建立了内陆性多沙河流水沙运动的非恒定一维及平面二维数学模型。对水库水沙运动进行了一维非恒定数值模拟，并在水流及泥沙运动方程的计算方法上做了优化，对泥沙方程采用在相邻时层之间用差分法求解，而在同一时层上用分析法求解；运用Preissmann四点偏心差分格式离散水流方程，并在做了线性化近似处理后用追赶法求解，避免了繁琐的迭代计算。为了解决二维模型中的复杂边界问题，运用有限元法离散二维模型方程，对常微分方程系数矩阵运用质量集中原则近似处理，而后采用显式为预报、隐式为校正和迭代的差分计算格式求解常微分方程组，该计算过程稳定性比较好，计算效率较高，还可以避免产生数值振荡。在动边界问题上，引入虚拟水深处理后，计算域就不随流动域的变化而改变了，从而可以保证数值计算的连续性。本文对头屯河水库及叶尔羌河中游河段的水沙运动用所建立的两个数学模型分别进行了数值模拟，并把计算结果同实测值进行了对比验证，结果吻合良好，体现了模型及其计算方法的正确性和适用性。更多还原

【Abstract】 The mathematical model of unsteady one-dimensional and plane two-dimensional flow-sediment in continental sediment-laden river is created in this paper. It applied in one-dimensional unsteady numerical modeling of the reservoir flow-sediment movement, and have a optimization to the numerical method of flow and sediment equation of motion, that is evaluation sediment equation with FDM between the adjacent time-layer, then evaluation the solution with FAM in the same time-layer; the flow equation is varianced by Preissmann four-point-eccentricity difference scheme, and evaluation the solution with Pursuit Method after linearization, so avoid the complex iterative computing. In order to solve the complex boundary problem in two-dimensional model, the two-dimensional model equation is varianced by FEM, the coefficient matrix of ordinary differential equation is dealt with mass-concentration principle, then evaluation the set of ordinary differential equations by using the difference scheme which explicit is prediction and implicit is adjustment and iteration, the stability of calculation process is good, and the efficiency of calculation is high, it can also avoid the value unstable. With the unstable boundary problem, after draw into the virtual water depth , the calculating region will not transform with the flow region’s change, so it can ensure the continuous of numerical calculation. These two mathematical model are applied in numerical modeling of the flow-sediment movement of Toutunhe Reservoir and Yeerqiang river middle course , and compared the numerical results with the measured values, the result indicate that the numerical results are in agreement with the measured values, and it also indicate the model and numerical method’s reliability and adaptability.更多还原