【作者】 金哲；

【导师】 王长新； 邱秀云； 侯杰； 周著；

【作者基本信息】 新疆农业大学 ， 水力学及河流动力学， 2007， 硕士

【摘要】 无压隧洞是常见的输水和泄水建筑物,在水利工程中有着广泛的应用。在过流时隧洞中可能会出现明满流交替等一系列对结构安全不利的水流现象,因此,在隧洞进口处合理设置洞内消能工,可有效改善隧洞结构的受力状况及消能效果,同时降低工程造价。清楚的了解隧洞内的水流流态及流场是设计洞内消能工结构的依据与关键。本文结合喀什河吉林台一级水电站引水深孔无压隧洞洞内消能工进行的水工及水力学模型试验,对无压隧洞洞内消能工进行了全面深入的研究。通过比较各种追踪自由面的方法,选择了流体体积法(VOF方法)来模拟自由水面,并与RNG k-ε紊流模型耦合建立了无压隧洞内消能工的水气二相流数学模型。根据不同的运行工况,利用计算流体力学软件FLUENT对无压隧洞洞内消能工的水流流态进行了二维简化数学模型的数值模拟,在求解过程中采用混合结构网格来处理复杂的边界形状;采用了效率较高PISO算法进行计算,在计算过程中进行了相邻校正和偏斜校正,减少了达到收敛所需的迭代次数。数值模拟计算所得到的洞内水流流态、速度场、消能率等与模型实测数据吻合良好,为设计此种深孔无压隧洞洞内消能工的型式提供了合理的参考依据。更多还原

【Abstract】 As a water conveyance and discharging building, free flow tunnel is very commonly used in the hydraulic engineering. Some detrimental flow such as half pressure flow will appear when stream go through the tunnel. Therefore, it can improve stress condition, increase energy dissipation effect and reduce cost of construction to set up energy dissipater at inlet of a tunnel. It is very important to understand the flow flied in the energy dissipater in tunnel for determining the size and structure style of internal energy dissipation. Compared with model experiment data of the Jilintai hydropower station, a two-dimensional numerical model is developed to simulate the flow filed in energy dissipater in non-pressure tunnel by using the volume of flow (VOF) method and RNG k-εtwo equations turbulent model.The flow pattern and flow field in the energy dissipater in tunnel are simulated with the two-dimensional numerical model under different operating conditions. The non-structure grid is used for complex irregular boundary processing. An efficient algorithm PISO is used for the model and it can correct the bias of the mesh, so it can reduce iterative times. The flow pattern, energy dissipation ratio and velocity field are obtained. The calculated results are in good agreement with experimental data and provide the bases for optimal design of the energy dissipation in free-flow tunnel.更多还原