SYSTEM DESIGN FOR THE EXPERIMENTAL GENERATION OF TWO-PHASE FLOW AT NEAR-AMBIENT TEMPERATURES

Open Access
Author:
Zarger, Colby Ronald
Area of Honors:
Mechanical Engineering
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Alexander S Rattner, Thesis Supervisor
  • Jacqueline Antonia O'Connor, Honors Advisor
Keywords:
  • two-phase
  • slug flow
  • visualization
  • heat transfer
Abstract:
Due to the complexity of fluid-thermal interactions, heat transfer effects in two-phase fluid systems are not thoroughly understood. One area of particular interest is how large-scale two-phase flow structures, such as vapor slugs, interact with small nucleating bubbles on a heated surface. A research team in the Multiscale Thermal Fluids and Energy Lab at Penn State is interested in expanding knowledge in this area by conducting experimental research on local heat transfer in two-phase slug flow. Several research questions are of interest: • How does the wake of a large vapor slug interact with nucleating bubbles on a heated surface? How does an incline of the channel affect these interactions? • How does the spacing between vapor slugs affect their interactions with nucleating vapor bubbles? • How does vapor slug length develop along a heated channel? How does the incline of the channel affect this development? The answers to these fundamental questions have practical applications in heat exchanger design for power generation systems, water desalination processes, and refrigeration systems. To enable this research, an experimental facility was developed in this thesis research project that is capable of creating the desired two-phase flow conditions. The system is composed of multiple components which provide fluid storage, filtering, pumping, metering, heating, boiling, and pressurization. A preliminary adiabatic test section was installed in order to demonstrate the functionality of the facility. Future research conducted with this facility will involve the development of a more complex test section designed to observe specific flow boiling phenomena. This thesis presents design-related details and choices associated with the development and construction of this facility. Design schematics and specific component selections are described in detail. Operating procedures are presented to ensure the safe operation of the system. Preliminary shadowgraph imagery of slug flow produced by the system is presented. The paper concludes with recommendations for future development and research goals for the experimental facility. The experimental portion of this project was supported, in part, by US NSF grant CBET 1652578.