Graduate Thesis Or Dissertation

 

Micro-bubble dynamics in two-phase flow through a micro-channel Public Deposited

Downloadable Content

Download PDF
https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/2n49t4353

Descriptions

Attribute NameValues
Creator
Abstract
  • An experimental investigation into the behavior of micro-bubbles flowing through a micro-channel has been conducted. Experiments were performed within a rectangular micro-channel with dimensions of 5 cm x 13.2 mm x l30 jim. Bubbles were generated in an electrolyte solution by electrolysis at the lower channel wall near the inlet. A non-intrusive optical set-up utilizing laser induced fluoresce (LIF) from Rhodamine 6G and particle image velocimetry (PIV) seed particles was developed to obtain information on both phases of the flow using a single camera. The gas phase measurements are discussed here, while fluid phase data is discussed in a concurrent study. Measurements of bubble size, distribution, and area fraction were taken at four different heights above the lower channel wall for three different flow rates (40 mL/min, 80 mL/min, and 100 mL/min) and two different electrolysis voltages used to generate the bubbles. Digital images were processed with an involved, active algorithm intended to reduce noise. Bubble velocity measurements were obtained through a bubble pairing algorithni. It is determined that the use of electrolysis for bubble generation provides poor control of global area fractions while producing a non-homogenous bubble distribution across the channel width. Experimental results reveal that much noise remains after the digital image processing. Despite this, it is found that for measurements taken at the same channel position and local area fraction an increase in flow rate leads to an increase in mean separation distance of the bubbles. There is also evidence to suggest that under these conditions an increased flow rate causes small bubbles to disperse more quickly into the channel than large bubbles. The bubble velocity results are shown to be very questionable by comparison with theoretical flow rates through the channel. Finally, a sensitivity analysis is done on the digital image processing technique used which reveals possible improvements that can be made to improve noise reducing capabilities.
License
Resource Type
Date Available
Date Issued
Degree Level
Degree Name
Degree Field
Degree Grantor
Commencement Year
Advisor
Academic Affiliation
Non-Academic Affiliation
Subject
Rights Statement
Publisher
Peer Reviewed
Language
Digitization Specifications
  • File scanned at 300 ppi (Monochrome, 8-bit Grayscale, 24-bit Color) using ScandAll PRO 1.8.1 on a Fi-6770A in PDF format. CVista PdfCompressor 4.0 was used for pdf compression and textual OCR.
Replaces

Relationships

Parents:

This work has no parents.

In Collection:

Items