水利工程師對潰壩洪水的預測非常感興趣,這類極端事件中水位和速度的變化是防洪控制的重要參數。從前的研究大多數使用水槽實驗和二維淺水方程來研究洪水波在平滑通道或通過不可滲透障礙物。本研究使用三維數值模型和水槽實驗來研究潰壩波與孔隙結構之交互作用。通過大渦模擬(LES)模型模擬周圍之自由水面及流場之流動情形,並通過流體體積 (VOF)方法來計算水面的變化。多孔障礙物對水流的影響由多孔阻力模型模擬。並通過波高計和數位照相機測量水表面高度等實驗數據的比較來證明模式本身的可信度與準確度。待驗證成功後,本模式即可被用於研究孔隙結構物對潰壩流的影響。數值結果表明,多孔隙阻力模型可以用於模擬多孔障礙物的阻力。;The prediction of dambreak floods is of great interest to hydraulic engineers. Variations of water level and velocity in these extreme events are important parameters for the design of hydraulic systems and for flood control. Most of the previous studies used flume experiments and two-dimensional shallow water equations to investigate the flood waves over smooth channels or through impermeable obstacles. This study uses a three-dimensional numerical model and flume experiments to investigate dambreak flows through porous obstacles on the channel bed. The flow motion was simulated by a Large Eddy Simulation (LES) model, and the variation of water surface was solved by the Volume of Fluid (VOF) method. The effect of porous obstacles to the water flows was simulated by the a porous drag model. The variation of water surface in the water flume was measured by a wave gauge and a digital camera. The simulated water surface was validated by the measured surface elevation. Furthermore, the verified numerical model was then used to study the influences of the porosity of obstacles to the dambreak flows. Numerical results reveal that the resistance of the porous obstacle can be simulated by a porous drag model.