{"id":{"repo_id":"uic","oai_identifier":"oai:figshare.com:article/31451470"},"canonical_url":"https://search.dev.ndltd.org/etd/uic/oai:figshare.com:article/31451470","repository":{"repo_id":"uic","name":"University of Illinois - Chicago","base_url":"https://api.figshare.com/v2/oai"},"display":{"title":"Computational Fluid Dynamics-Informed Analysis of Diaphragm-Free Shock Tubes and Insert Designs","abstract":"The design and simulation of a novel, compact, diaphragm-free shock tube is presented using computational fluid dynamics (CFD) in ANSYS Fluent 2022 R1 to better understand shock tube behavior for improved control in high-pressure, high-temperature shock experiments. The study quantifies geometric and viscous effects by evolving from an idealized diaphragm-controlled inviscid straight shock tube to a viscous wrap-around configuration featuring a retracting plate valve in place of a diaphragm. Different valve opening speeds are assessed at matched P4/P1 pressure ratios and matched shock velocities, isolating the effects of valve motion on shock formation and test section conditions. A driver insert is designed and evaluated to control the rate of rise behind the reflected shock. The study assesses shock structure, rate of rise, and temporal homogeneity using computationally generated x-t diagrams, numerical Schlieren imaging, pressure contours, and test time pressure and temperature data. Valve-based and diaphragm-based configurations are compared to analyze the impact of valve opening speed, pressure ratio, and insert geometry on shock uniformity and test time characteristics. The geometric evolution and viscous effects leading to the compact, wrap-around, diaphragm-free shock tube are examined, beginning with an inviscid straight shock tube. Viscosity and boundary layer development are assessed in a straight shock tube, followed by the addition of a wrap-around driver section and a valve housing (plenum). Upstream influences on shock structure, wave uniformity, and flow evolution in the test section are examined. The valve is then incorporated by simulating a retracting plate valve at an experimentally predicted opening speed of 10.16 m/s. The impact of the valve on shock uniformity, turbulence generation, compression wave attenuation, and the overall test time performance is analyzed. Additional simulations at valve opening speeds of 5.08 m/s and 20.32 m/s examine valve speed effects under matched P4/P1 pressure ratios and matched shock velocities. The trade-offs between valve speed, rate of rise, homogeneity, and test duration are identified. It is found that increasing valve speed reduces the rate of rise behind the reflected shock but introduces greater temporal inhomogeneity, revealing a critical balance between rapid shock formation and uniform test conditions. Driver insert effects are explored through parametric studies, varying the insert width (diameter), length, and head angle/shape to assess their impact on shock attenuation and rate of rise at a constant P4/P1 pressure ratio. An optimal driver insert configuration is designed based on its ability to sustain uniform test conditions across various P4/P1 pressure ratios. This work advances the understanding of unsteady compressible flow physics by establishing a simulation framework for moving-valve systems using Chimera mesh techniques. It examines the role of valve speed on shock formation and test section performance. The impact of a driver insert on the flow uniformity and test time conditions is assessed, and an initial comparison between 2D CFD predictions and experimental results is presented.","abstract_html":"The design and simulation of a novel, compact, diaphragm-free shock tube is presented using computational fluid dynamics (CFD) in ANSYS Fluent 2022 R1 to better understand shock tube behavior for improved control in high-pressure, high-temperature shock experiments. The study quantifies geometric and viscous effects by evolving from an idealized diaphragm-controlled inviscid straight shock tube to a viscous wrap-around configuration featuring a retracting plate valve in place of a diaphragm. Different valve opening speeds are assessed at matched P4/P1 pressure ratios and matched shock velocities, isolating the effects of valve motion on shock formation and test section conditions. A driver insert is designed and evaluated to control the rate of rise behind the reflected shock. The study assesses shock structure, rate of rise, and temporal homogeneity using computationally generated x-t diagrams, numerical Schlieren imaging, pressure contours, and test time pressure and temperature data. Valve-based and diaphragm-based configurations are compared to analyze the impact of valve opening speed, pressure ratio, and insert geometry on shock uniformity and test time characteristics. The geometric evolution and viscous effects leading to the compact, wrap-around, diaphragm-free shock tube are examined, beginning with an inviscid straight shock tube. Viscosity and boundary layer development are assessed in a straight shock tube, followed by the addition of a wrap-around driver section and a valve housing (plenum). Upstream influences on shock structure, wave uniformity, and flow evolution in the test section are examined. The valve is then incorporated by simulating a retracting plate valve at an experimentally predicted opening speed of 10.16 m/s. The impact of the valve on shock uniformity, turbulence generation, compression wave attenuation, and the overall test time performance is analyzed. Additional simulations at valve opening speeds of 5.08 m/s and 20.32 m/s examine valve speed effects under matched P4/P1 pressure ratios and matched shock velocities. The trade-offs between valve speed, rate of rise, homogeneity, and test duration are identified. It is found that increasing valve speed reduces the rate of rise behind the reflected shock but introduces greater temporal inhomogeneity, revealing a critical balance between rapid shock formation and uniform test conditions. Driver insert effects are explored through parametric studies, varying the insert width (diameter), length, and head angle/shape to assess their impact on shock attenuation and rate of rise at a constant P4/P1 pressure ratio. An optimal driver insert configuration is designed based on its ability to sustain uniform test conditions across various P4/P1 pressure ratios. This work advances the understanding of unsteady compressible flow physics by establishing a simulation framework for moving-valve systems using Chimera mesh techniques. It examines the role of valve speed on shock formation and test section performance. The impact of a driver insert on the flow uniformity and test time conditions is assessed, and an initial comparison between 2D CFD predictions and experimental results is presented.","abstract_has_math":false,"creators":["Alex Powers (10089460)"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2025,"date_issued":"2025-12-01T00:00:00Z","date_published":"2025-12-01T00:00:00Z","updated_at":"2026-07-27T21:34:27Z","subjects":["Physics, Compressible Flow","Math, Computational Fluid Dynamics","Physics, Theory","Math"],"languages":[],"rights":["In Copyright"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://doi.org/10.25417/uic.31451470.v1","outbound_label":"DOI","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:creator","label":"Author","values":["Alex Powers (10089460)"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2025-12-01T00:00:00Z"]},{"key":"dc:relation","label":"Dc Relation","values":["https://figshare.com/articles/thesis/Computational_Fluid_Dynamics-Informed_Analysis_of_Diaphragm-Free_Shock_Tubes_and_Insert_Designs/31451470"]},{"key":"dc:type","label":"Dc Type","values":["Text","Thesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Physics, Compressible Flow","Math, Computational Fluid Dynamics","Physics, Theory","Math"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["10.25417/uic.31451470.v1"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["The design and simulation of a novel, compact, diaphragm-free shock tube is presented using computational fluid dynamics (CFD) in ANSYS Fluent 2022 R1 to better understand shock tube behavior for improved control in high-pressure, high-temperature shock experiments. The study quantifies geometric and viscous effects by evolving from an idealized diaphragm-controlled inviscid straight shock tube to a viscous wrap-around configuration featuring a retracting plate valve in place of a diaphragm. Different valve opening speeds are assessed at matched P4/P1 pressure ratios and matched shock velocities, isolating the effects of valve motion on shock formation and test section conditions. A driver insert is designed and evaluated to control the rate of rise behind the reflected shock. The study assesses shock structure, rate of rise, and temporal homogeneity using computationally generated x-t diagrams, numerical Schlieren imaging, pressure contours, and test time pressure and temperature data. Valve-based and diaphragm-based configurations are compared to analyze the impact of valve opening speed, pressure ratio, and insert geometry on shock uniformity and test time characteristics. The geometric evolution and viscous effects leading to the compact, wrap-around, diaphragm-free shock tube are examined, beginning with an inviscid straight shock tube. Viscosity and boundary layer development are assessed in a straight shock tube, followed by the addition of a wrap-around driver section and a valve housing (plenum). Upstream influences on shock structure, wave uniformity, and flow evolution in the test section are examined. The valve is then incorporated by simulating a retracting plate valve at an experimentally predicted opening speed of 10.16 m/s. The impact of the valve on shock uniformity, turbulence generation, compression wave attenuation, and the overall test time performance is analyzed. Additional simulations at valve opening speeds of 5.08 m/s and 20.32 m/s examine valve speed effects under matched P4/P1 pressure ratios and matched shock velocities. The trade-offs between valve speed, rate of rise, homogeneity, and test duration are identified. It is found that increasing valve speed reduces the rate of rise behind the reflected shock but introduces greater temporal inhomogeneity, revealing a critical balance between rapid shock formation and uniform test conditions. Driver insert effects are explored through parametric studies, varying the insert width (diameter), length, and head angle/shape to assess their impact on shock attenuation and rate of rise at a constant P4/P1 pressure ratio. An optimal driver insert configuration is designed based on its ability to sustain uniform test conditions across various P4/P1 pressure ratios. This work advances the understanding of unsteady compressible flow physics by establishing a simulation framework for moving-valve systems using Chimera mesh techniques. It examines the role of valve speed on shock formation and test section performance. The impact of a driver insert on the flow uniformity and test time conditions is assessed, and an initial comparison between 2D CFD predictions and experimental results is presented."]},{"key":"dc:title","label":"Title","values":["Computational Fluid Dynamics-Informed Analysis of Diaphragm-Free Shock Tubes and Insert Designs"]}]}],"canonical_facts":{"dc:creator":["Alex Powers (10089460)"],"dc:date":["2025-12-01T00:00:00Z"],"dc:description":["The design and simulation of a novel, compact, diaphragm-free shock tube is presented using computational fluid dynamics (CFD) in ANSYS Fluent 2022 R1 to better understand shock tube behavior for improved control in high-pressure, high-temperature shock experiments. The study quantifies geometric and viscous effects by evolving from an idealized diaphragm-controlled inviscid straight shock tube to a viscous wrap-around configuration featuring a retracting plate valve in place of a diaphragm. Different valve opening speeds are assessed at matched P4/P1 pressure ratios and matched shock velocities, isolating the effects of valve motion on shock formation and test section conditions. A driver insert is designed and evaluated to control the rate of rise behind the reflected shock. The study assesses shock structure, rate of rise, and temporal homogeneity using computationally generated x-t diagrams, numerical Schlieren imaging, pressure contours, and test time pressure and temperature data. Valve-based and diaphragm-based configurations are compared to analyze the impact of valve opening speed, pressure ratio, and insert geometry on shock uniformity and test time characteristics. The geometric evolution and viscous effects leading to the compact, wrap-around, diaphragm-free shock tube are examined, beginning with an inviscid straight shock tube. Viscosity and boundary layer development are assessed in a straight shock tube, followed by the addition of a wrap-around driver section and a valve housing (plenum). Upstream influences on shock structure, wave uniformity, and flow evolution in the test section are examined. The valve is then incorporated by simulating a retracting plate valve at an experimentally predicted opening speed of 10.16 m/s. The impact of the valve on shock uniformity, turbulence generation, compression wave attenuation, and the overall test time performance is analyzed. Additional simulations at valve opening speeds of 5.08 m/s and 20.32 m/s examine valve speed effects under matched P4/P1 pressure ratios and matched shock velocities. The trade-offs between valve speed, rate of rise, homogeneity, and test duration are identified. It is found that increasing valve speed reduces the rate of rise behind the reflected shock but introduces greater temporal inhomogeneity, revealing a critical balance between rapid shock formation and uniform test conditions. Driver insert effects are explored through parametric studies, varying the insert width (diameter), length, and head angle/shape to assess their impact on shock attenuation and rate of rise at a constant P4/P1 pressure ratio. An optimal driver insert configuration is designed based on its ability to sustain uniform test conditions across various P4/P1 pressure ratios. This work advances the understanding of unsteady compressible flow physics by establishing a simulation framework for moving-valve systems using Chimera mesh techniques. It examines the role of valve speed on shock formation and test section performance. The impact of a driver insert on the flow uniformity and test time conditions is assessed, and an initial comparison between 2D CFD predictions and experimental results is presented."],"dc:identifier":["10.25417/uic.31451470.v1"],"dc:relation":["https://figshare.com/articles/thesis/Computational_Fluid_Dynamics-Informed_Analysis_of_Diaphragm-Free_Shock_Tubes_and_Insert_Designs/31451470"],"dc:rights":["In Copyright"],"dc:subject":["Physics, Compressible Flow","Math, Computational Fluid Dynamics","Physics, Theory","Math"],"dc:title":["Computational Fluid Dynamics-Informed Analysis of Diaphragm-Free Shock Tubes and Insert Designs"],"dc:type":["Text","Thesis"]},"updated_at":"2026-07-27T21:34:27Z"}