After a comprehensive review on the study of sediment density current in the recent several decades , a set of differential equations for 2 - d density current under double - layer computational mode is established . by simplifying th . set of equations , a 2 - d numerical simulation of sediment density current and sediment outflow has been made in the liujiaxia reservoir in the yellow river basin , and the result is reasonable 本论文在对异重流运动近几十年来的研究成果进行较系统、全面论述的基础上，针对目前研究较为前沿的异重流运动数值模拟问题，提出了一套二维异重流双层计算模式下的基本方程，并在这套方程简化的基础上，对黄河流域刘家峡水库中的异重流运动和排沙进行了二维数值模拟，结果令人较为满意。
On the one hand , the sediment density current often does a great harm to the reservoir , and causes a big loss of reservoir ' s storage capacity or makes reservoir severe deposition ; on the other hand , sediment outflow by density current is an effective measure to mitigate sedimentation 异重流(本论文中主要指因含沙量的差异而形成的浑水异重流)一方面常常给水库带来严重的危害，加速水库的淤积和库容的损失；但另一方面它又为水库排沙提供了一种极为有效的途径? ?水库异重流排沙。
