摘要: |
为进一步研究田间便携式短喉槽过槽的水流特性及测流精度,基于临界流原理和RNG k-ε三维湍流模型,利用FLOW-3D软件对喉道宽度为76 mm的田间便携式短喉槽在16种工况下的水力特性进行全流场数值计算,获得了时均流场、槽内水流流态、断面流速分布及佛汝德数,并与试验实测值进行对比分析。结果表明:1)模拟流场分布及流态与模型试验情况具有一致性,量测流量范围宽,最大可达40 L/s,能够满足田间量水的流量要求;2)水深、断面流速、佛汝德数模拟值与实测值基本吻合,相对误差均小于10%;3)该短喉槽最大水头损失占总水头的12.89%,小于长喉槽最大水头损失占总水头的13%;4)通过回归分析得到了田间便携式短喉槽的上游水深-流量计算公式,其最大测流误差为9.95%,满足灌区量水精度的要求。 |
关键词: 田间便携式短喉槽 数值模拟 流场 流速 佛汝德数 水头损失 上游水深-流量公式 |
DOI:10.11841/j.issn.1007-4333.2016.05.017 |
投稿时间:2015-06-04 |
基金项目:杨凌示范区科技计划项目(2015NY-30);公益性行业(农业)科研专项(201503125);国家自然科学基金项目(51179163) |
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Numerical simulation of portable short-throat flume in the field |
XIAO Yi-zhou, WANG Wen-e, HU Xiao-tao
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(College of Water Resources and Architectural Engineering, Northwest A&F University, Yangling 712100, China) |
Abstract: |
Portable short-throat flume, which measuring the discharges of water inlet in the field, is a new flow-measuring device.Based on the principle of critical flow and RNG k-ε three-dimensional turbulence model, simulations of 16 working conditions by FLOW-3D software were carried out on the portable short-throat flume with 76 mm width to study hydraulic performance.The time-averaged flow field, flow regime, velocity distribution and Froude numbers were obtained and compared with measure values.The results showed that:Simulated values were consistent with the measured values within ±10% errors and the measuring range of the flume was up to 40 L/s;Compared to long-throat flume, the head loss of portable short-throat flume in the field was less;Furthermore, equations of upstream depth with discharge under different working conditions were fitted by regression analyses, and the relative error was less than 9.95%.In conclusion, the portable short-throat flume in the field meets the demand for precise measurement of discharges of water inlet in the field. |
Key words: portable short-throat flume in the field numerical simulation flow field velocity Froude number head loss equations of upstream depth with discharge |