【摘要】 旨在获取上游安装单个90°弯头条件时内锥流量计所需要的最短直管段长度。将计算流体动力学数值仿真和实流实验有机结合,通过数值仿真揭示速度场与压力的分布信息,预测上游弯头及直管段长度对内锥流量计流出系数的影响规律,并结合实流实验进行验证。仿真和实验的介质均为常温水,雷诺数范围分别为0.498×105～4.98×105和0.14×105～5.1×105。实验包含基线实验与弯头实验两种类型,以基线实验为基准,其中节流比分别为0.45/0.65/0.85,利用平均流出系数相对误差及附加不确定度作为安装条件影响的主要评价标准,给出上游单个90°弯头的直管段长度,并与国外研究结论进行了比较。更多还原

【Abstract】 In this paper we investigate the shortest straight pipe length of cone flowmenter required for the installation of upstream single 90° elbow.By revealing the distribution information of velocity field and pressure via numerical simulation,we forecast the influence of the upstream elbow and straight pipe length on the discharge coefficient of the cone flowmeter,and verify the results with experiment.The mediums of simulation and experiment are water with normal temperature,and the Reynolds numbers of the water are 0.498×105～4.98×105 and 0.14×105～5.1×105,respectively.There are two types of experiments namely,the baseline and elbow experiments,and the former one is used as the reference.The equivalent diameter ratios of the cone flowmeter are 0.45/0.65/0.85 respectively.Using the relative error and additive uncertainty of the averaged discharge coefficient as the main evaluating criterions,we obtain the length of the straight pipe for the upstream single 90° elbow,and compare the result with that of foreign study.更多还原