{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/124583"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/124583","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Design and Testing of a Bubble Generator for Molten Salt Surrogate Fluid","abstract":"This study explores the design, testing, and modeling of a bubble injector intended for use in studying bubble dynamics in molten salt reactors using a room temperature surrogate fluid by matching the Reynolds number, Eötvös number, and Morton number defined by the properties of the helium bubbles in the pump bowl of the Molten Salt Reactor Experiment (MSRE). The injector, constructed from polydimethylsiloxane (PDMS) and acrylic, was tested to generate bubbles within a precise size range suitable for simulating conditions in molten salt reactors. Experimental data showed that the equivalent bubble diameter is directly proportional to gas flow rate and inversely proportional to liquid flow rate, with clear trends emerging when data were subdivided into constant flow rate plots. The study applied and adapted the bubble size control model proposed by Lu et al. (2014), revealing limitations in existing models under modified conditions such as an elongated two-phase channel. A novel model was developed to better predict bubble size, incorporating dependencies on both flow rate ratios and the capillary number of the microchannels. The injector's design facilitates convenient modifications in channel geometry to achieve target bubble sizes, and future improvements in pressure monitoring and imaging are recommended. This work contributes to the advancement of microfluidic bubble injection technology.","abstract_html":"This study explores the design, testing, and modeling of a bubble injector intended for use in studying bubble dynamics in molten salt reactors using a room temperature surrogate fluid by matching the Reynolds number, Eötvös number, and Morton number defined by the properties of the helium bubbles in the pump bowl of the Molten Salt Reactor Experiment (MSRE). The injector, constructed from polydimethylsiloxane (PDMS) and acrylic, was tested to generate bubbles within a precise size range suitable for simulating conditions in molten salt reactors. Experimental data showed that the equivalent bubble diameter is directly proportional to gas flow rate and inversely proportional to liquid flow rate, with clear trends emerging when data were subdivided into constant flow rate plots. The study applied and adapted the bubble size control model proposed by Lu et al. (2014), revealing limitations in existing models under modified conditions such as an elongated two-phase channel. A novel model was developed to better predict bubble size, incorporating dependencies on both flow rate ratios and the capillary number of the microchannels. The injector's design facilitates convenient modifications in channel geometry to achieve target bubble sizes, and future improvements in pressure monitoring and imaging are recommended. This work contributes to the advancement of microfluidic bubble injection technology.","abstract_has_math":false,"creators":["Breeden, Courts Holland"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Nuclear Engineering","degree_department":"Mechanical Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Liu, Yang"],"committee_members":["Haghighat, Alireza","Freeman, David Wayne"],"year":2025,"date_issued":"2025-02-13","date_published":"2025-02-13","updated_at":"2026-07-22T22:20:37Z","subjects":["Thermal-hydraulics","Molten Salt","Microfluidics","Surrogate fluid"],"languages":["en"],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:41672"],"render_values":[{"text":"vt_gsexam:41672","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/10919/124583","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Liu, Yang"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Haghighat, Alireza","Freeman, David Wayne"]},{"key":"dc:contributor.department","label":"Department","values":["Mechanical Engineering"]},{"key":"dc:creator","label":"Author","values":["Breeden, Courts Holland"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2025-02-14T09:01:00Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2025-02-14T09:01:00Z"]},{"key":"dc:date.issued","label":"Date","values":["2025-02-13"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Nuclear Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Thermal-hydraulics","Molten Salt","Microfluidics","Surrogate fluid"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language.iso","label":"Language (ISO)","values":["en"]},{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["vt_gsexam:41672"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10919/124583"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This study explores the design, testing, and modeling of a bubble injector intended for use in studying bubble dynamics in molten salt reactors using a room temperature surrogate fluid by matching the Reynolds number, Eötvös number, and Morton number defined by the properties of the helium bubbles in the pump bowl of the Molten Salt Reactor Experiment (MSRE). The injector, constructed from polydimethylsiloxane (PDMS) and acrylic, was tested to generate bubbles within a precise size range suitable for simulating conditions in molten salt reactors. Experimental data showed that the equivalent bubble diameter is directly proportional to gas flow rate and inversely proportional to liquid flow rate, with clear trends emerging when data were subdivided into constant flow rate plots. The study applied and adapted the bubble size control model proposed by Lu et al. (2014), revealing limitations in existing models under modified conditions such as an elongated two-phase channel. A novel model was developed to better predict bubble size, incorporating dependencies on both flow rate ratios and the capillary number of the microchannels. The injector's design facilitates convenient modifications in channel geometry to achieve target bubble sizes, and future improvements in pressure monitoring and imaging are recommended. This work contributes to the advancement of microfluidic bubble injection technology."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["This study focuses on developing and testing a device that creates tiny bubbles to help us better understand bubble behavior in advanced nuclear reactors, specifically molten salt reactors. These reactors use a special type of liquid fuel, and understanding how bubbles move within them is important for improving their efficiency and safety. To simulate the conditions inside these reactors without using the actual molten salt, we used a substitute fluid that has similar properties to the molten salt and built a bubble injector made from clear, flexible materials. Our experiments showed that the size of the bubbles depends on the flow rates of the gas and liquid: larger bubbles are formed when more gas is injected, and smaller bubbles are created when the liquid flow is increased. We tested existing models that predict bubble size and found that they didn't always work well under the conditions we used, like longer channels where the gas and liquid mix. As a result, we developed a new model that better predicts bubble size by considering both flow rates and the Capillary number of the microchannels. The design of our injector allows for easy adjustments to make bubbles of different sizes, and we suggest future improvements in pressure measurement and camera equipment to enhance data accuracy."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Design and Testing of a Bubble Generator for Molten Salt Surrogate Fluid"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Liu, Yang"],"dc:contributor.committeemember":["Haghighat, Alireza","Freeman, David Wayne"],"dc:contributor.department":["Mechanical Engineering"],"dc:creator":["Breeden, Courts Holland"],"dc:date.accessioned":["2025-02-14T09:01:00Z"],"dc:date.available":["2025-02-14T09:01:00Z"],"dc:date.issued":["2025-02-13"],"dc:description.abstract":["This study explores the design, testing, and modeling of a bubble injector intended for use in studying bubble dynamics in molten salt reactors using a room temperature surrogate fluid by matching the Reynolds number, Eötvös number, and Morton number defined by the properties of the helium bubbles in the pump bowl of the Molten Salt Reactor Experiment (MSRE). The injector, constructed from polydimethylsiloxane (PDMS) and acrylic, was tested to generate bubbles within a precise size range suitable for simulating conditions in molten salt reactors. Experimental data showed that the equivalent bubble diameter is directly proportional to gas flow rate and inversely proportional to liquid flow rate, with clear trends emerging when data were subdivided into constant flow rate plots. The study applied and adapted the bubble size control model proposed by Lu et al. (2014), revealing limitations in existing models under modified conditions such as an elongated two-phase channel. A novel model was developed to better predict bubble size, incorporating dependencies on both flow rate ratios and the capillary number of the microchannels. The injector's design facilitates convenient modifications in channel geometry to achieve target bubble sizes, and future improvements in pressure monitoring and imaging are recommended. This work contributes to the advancement of microfluidic bubble injection technology."],"dc:description.abstractgeneral":["This study focuses on developing and testing a device that creates tiny bubbles to help us better understand bubble behavior in advanced nuclear reactors, specifically molten salt reactors. These reactors use a special type of liquid fuel, and understanding how bubbles move within them is important for improving their efficiency and safety. To simulate the conditions inside these reactors without using the actual molten salt, we used a substitute fluid that has similar properties to the molten salt and built a bubble injector made from clear, flexible materials. Our experiments showed that the size of the bubbles depends on the flow rates of the gas and liquid: larger bubbles are formed when more gas is injected, and smaller bubbles are created when the liquid flow is increased. We tested existing models that predict bubble size and found that they didn't always work well under the conditions we used, like longer channels where the gas and liquid mix. As a result, we developed a new model that better predicts bubble size by considering both flow rates and the Capillary number of the microchannels. The design of our injector allows for easy adjustments to make bubbles of different sizes, and we suggest future improvements in pressure measurement and camera equipment to enhance data accuracy."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:41672"],"dc:identifier.uri":["https://hdl.handle.net/10919/124583"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Thermal-hydraulics","Molten Salt","Microfluidics","Surrogate fluid"],"dc:title":["Design and Testing of a Bubble Generator for Molten Salt Surrogate Fluid"],"dc:type":["Thesis"],"thesis:degree_discipline":["Nuclear Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:20:37Z"}