Dispersion in oscillatory flows

• Main Author: Song, Jie
• Other Authors: Law Wing-Keung, Adrian
• Format: Theses and Dissertations
• Language: English
• Published: 2014
• Subjects: DRNTU::Engineering::Environmental engineering::Environmental pollution
• Online Access: https://hdl.handle.net/10356/61784
• Institution: Nanyang Technological University

Compared to the in-depth understanding of dispersion in steady flows, the knowledge of dispersion in oscillatory flows is relatively un-developed, even though the topic is relevant to many practical problems. A few topics on the dispersion in oscillatory flows are investigated in this thesis. They include the dispersion in progressive and standing waves, the longitudinal dispersion in pressure-driven turbulent oscillatory pipe flows and in turbulent oscillatory flows generated by vibrating boundaries, and the dispersion of oscillatory electro-osmotic flows in nano- and micro-channels. Analytical analyses based on the homogenization method are performed to investigate the dispersion coefficient for different cases. Meanwhile, an experimental study is conducted to examine the longitudinal dispersion in oscillatory pipe flows by using the advanced laser techniques Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF). The results suggest that the dispersion coefficient depends on the flow characteristics as well as the pipe/channel geometry, and the effects vary case by case.