波浪对温差异重流垂向温度场影响的试验研究  

Experiments on wave effects on vertical temperature field of thermal density flow

作　　者：刘彦[1] 纪平[1] 赵懿珺[1] 彭莘仔 LIU Yan;JI Ping;ZHAO Yijun;PENG Xinzai(China Institute of Water Resources and Hydropower Research,Beijing 100038,China)

机构地区：[1]中国水利水电科学研究院,北京100038

出　　处：《水利水电技术》2018年第10期100-109,共10页Water Resources and Hydropower Engineering

基　　金：中国水利水电科学研究院基本科研业务费专项项目(HY0145B152016)

摘　　要：为了解明渠排口下游温差异重流在有、无波浪作用下的掺混、扩散特性,采用直段水槽物理模型方法对其进行试验研究。热水排口模型参照电厂取排水工程实际应用长方形截面排水口结构进行设计,设置了静水面表层热水水平排放与环境冷水同向流动两套进水系统。试验分别测得有、无波浪作用下,排口下游4个断面各测点的温度、流速等脉动物理量,重点分析了两种工况下排口下游垂向温度场分布规律。结果表明,无波浪时,同向冷、热水流产生温差异重流分界面不明显;距离排口越远,各断面垂向总体理查森数越小,即流体浮力效应越弱。波浪运动产生强烈紊动效应,能够破坏温差异重流分层结构,增大温度垂向扩散系数(增大量级10-3),使上层水体温度混合均匀;波陡的增大,可加强排口下游温度场垂、纵向扩散水平,中轴线上表层各测点平均时均温升值在无波浪与有波浪作用时最大相差3倍。The vertical thermal density flow in the downstream of open-channel is experimentally studied with or without the effect of wave.Referring to the structure of outfalls with rectangular section in practice,two-layer flows with different velocity and temperature are produced by using two sets of independent inflow systems.The value of temperature,flow velocity and other fluctuating physical quantity of the 4 testing points of sections are systemically measured and the distributing characteristics of vertical temperature in two conditions are emphatically analyzed based on the experimental data.The result shows that the hot and cold water interface is not obvious and the farther away from outlet,the smaller Richardson number in no wave working condition.The strong turbulence effect caused by wave motion can destroy the layered structure of the thermal density flow,enhance the vertical diffusion coefficient(order of magnitude 10-3)and make the upper layer flow more homogeneous mixing.In addition,increase with the wave steepness,the vertical and longitudinal temperature diffusion level are strengthened and the largest average temperature rise on the central axis is only account for 1/3 of the situation without wave.

关 键 词：温差异重流 波浪 明渠 波陡 垂向热扩散特性 试验研究 

分 类 号：X145[环境科学与工程—环境科学]