摘要
本文利用超声多普勒测速仪和动态压力测量方法,研究90°矩形截面弯管中拟塑性流体(浓度为0.1%和0.2%的羧甲基化纤维素溶液,CMC)的流场特性,在三种来流速度条件下,测量了沿流向截面内的主流速度和壁面测点的压力脉动特性。在介质的流变性参数测量的基础上,实验观察了层流和湍流状态下弯道截面内拟塑性流体流动不均匀性的特征,并与牛顿流体流动的经典实验进行了对比分析。动态压力测量则显示了在湍流状态下,拟塑性流体仍具有牛顿流体湍流流动的多尺度特征。
This paper presents an experimental study of the flows of pseudoplastic liquids(carboxymethylcellulose solutions at concentrations of 0.1% and 0.2%,respectively) through a square-sectioned 90° bend,using a ultrasonic Doppler velocimeter and microphones.Distributions of the longitudinal velocity in cross-sections and wall pressure fluctuations were obtained at three inflow velocities.Rheological properties were also measured,and fitted for the liquids.The contours of velocity,for both laminar and turbulent flows,and their development in the streamwise direction.were presented and compared with benchmark experimental results for those flows of Newtonian fluids in literatures.The spectra of fluctuating wall pressures were also presented and analyzed.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2014年第12期2393-2397,共5页
Journal of Engineering Thermophysics
基金
国家自然科学基金项目(No.51176048)
关键词
弯管
拟塑性流体
流场
实验研究
curved duct
pseudoplastic liquids
flow fields
experimental study
