摘要
利用micro-PIV系统测量了去离子水在水力直径为237μ.m,长度为31mm的梯形截面微管道内的流场结构,得到了不同雷诺数下沿流动方向不同位置微管道中间截面上的速度分布,并利用数值模拟方法计算了相应雷诺数下三维梯形截面微管道内的速度分布.实验结果和数值模拟结果显示实验中的梯形截面微管道内从层流到湍流的转捩发生在Re=1500～1800左右,实验中充分发展段长度Le、微管道水力直径Dh和雷诺数之间的关系可由公式Le/Dh=(0.08～0.085)Re表示.
A micro-resolution particle image veloeimetry （micro-PIV） system has been used to measure the water flow in a micro-channel with trapezoid cross section. The micro-channel was 31mm long with a hydraulic diameter 237μm. Under various Reynolds numbers the velocity distributions of middle plane at the different positions along flow direction were obtained and compared with computational results. The entrance length in our experiments can be predicted by Le/Dh = （0.08 -0.085） Re. The velocity profiles obtained by micro-PIV indicate that the transition from laminar flow to turbulent flow oecurs for Reynolds number ranging from 1500 to 1800. This result is consistent with the numerical data.
出处
《实验流体力学》
CAS
CSCD
北大核心
2005年第3期94-98,共5页
Journal of Experiments in Fluid Mechanics
基金
国家自然科学基金资助项目(10272066)
