摘要
垂直上升矩形截面管内的气液两相流横向冲刷水平布置的柱体时，一定条件下会在柱体后部产生旋涡交替脱落现象，使柱体在与来流垂直的方向上受到脉动升力的作用。本文以截面分别是方形、正三角形的柱体为例，研究了这种带锐缘的柱体在气液两相流中受到的脉动升力，得出了涡街的Strouhal数和柱体的脉动升力系数C'L随Re数和来流含气率。的变化情况。实验结果表明：在本文的实验范围内，方形柱体和正三角柱体的Strouhal数不随Re数变化，而在一定的含气率范围内，随着含气率的增大而增大；C'L也不随Re数而变化，而随着来流含气率的增大相减小而后很快增大。
An experimental study was conducted to investigate fluctuating lifts on a square-section and a equilateral triangle-section cylinder when it was subjected to air/water two-phase crossflow. In the experiments, Reynolds number ranged from 0.9 ×104 to 4.2 ×104, and the void fraction in the main flow, a was varied from 0 to 0.32. The flow pattern of the two-phase flow was vertically upward bubbly flow. By analyzing the power spectra of the lift fluctuations,it is found that the Strouhal number of the vortex street shed from either cylinder increases with the void fraction, and the vortex street vanishes as a increases in excess of a certain value. The magnitudes of the fluctuating lifts on both cylinders are found to decrease first then to increase with the increase of the void fraction.
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
1999年第3期360-364,共5页
Journal of Engineering Thermophysics
基金
国家自然科学基金!19572052
关键词
气液
两相流
方柱
正三角柱
涡街
脉动升力
gas-liquid two-phase flow, square cylinder, triangle-section cylinder, vortex street, fluctuating lift
