紊动射流的近区初始稀释

本文研究运动淡水水体中紊动射流的近区掺混规律.应用紊动射流特征长度比尺法给出了射流中心线轨迹及初始稀释度模型.通过底部潜没扩散器排放与岸边单孔排放水槽试验,建立了扩散器工程参数:出口流速、孔数、扩散器长度、孔径等与污水带轨迹及初始稀释度之间的关系.以实例介绍了成果的工程应用.从稀释扩散能力看,底部潜没排放方式明显优于岸边排放方式.结果表明:长度比尺法物理概念明确、计算简单、应用方便,特别适合于扩散器工程的规划和初步设计.

Initial Dilution of Turbulent Jets in Near Field

In this paper, the near-field entrainment of turbulent jets in fresh ambient flow is discussed. The characteristic length scale principle is used to establish the model for centerline trajcctory and initial dilution. Through flume tests of multiport bottom diffuser and singleport wall jet the parameter are determined. The trajectory and dilution depond on a variety of engineering quantities, Such as outflow or ambient velocity, port numerber, port diameter, diffuser length, etc. From the view point of diffusing ability, submerge discharging is a choice far more efficient than side discharging.