不对称地形下进/出水口明渠段环流特性研究

为研究不对称地形下明渠段内的环流特性，以一抽水蓄能电站上水库为研究对象，对引水明渠内部的流场进行了详细的数值模拟分析。研究发现，由于明渠前方及两侧的地形边界不对称这类不利地形条件，明渠内产生了较大范围的环流，不仅影响明渠内的水流流态，还降低了各进/出水口拦污栅断面水流的均匀性，属不利的水流现象。针对这一情况，提出通过加大明渠连接段长度并扩大明渠一侧开挖范围可以使环流位置远离进/出水口，在一定程度上改善明渠内的水流流态，降低拦污栅断面水流不均匀程度，减小环流的不利影响。本文研究成果可以增大抽水蓄能电站进/出水口选址的灵活性，避免大范围的开挖，为抽水蓄能电站明渠布置方案的设计提供有益的参考。

Circulation characteristics of inlet/outlet open channel sections under asymmetric terrain

This study simulates the details of the flow in a diversion open channel at a pumped storage power station to study its circulation characteristics under asymmetric terrain. It has been found that a large-size circulation is generated in the channel due to unfavorable terrain conditions, such as the asymmetric terrain boundaries in front and on both sides of the channel. This not only affects the flow pattern in the open channel, but reduces flow uniformity in the trash rack section at the inlet/outlet, thereby producing unfavorable effects. To improve the flow, we suggest two measures ? increasing the length of connection to the channel and expanding the excavation at one side of the channel. Numerical simulations show that these measures can shift the circulation to locations far away from the inlet/outlet, thus improving the flow pattern to a certain extent and reducing flow non-uniformity and other adverse effects. This study provides engineering measures to adjust the intake/outlet location and avoid large-scale excavation for the design of diversion channels of pumped storage power stations.