{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/93038"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/93038","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Design and Analysis of Low Reynolds Number Marine Propellers with Computational Fluid Dynamics (CFD) Transition Modeling","abstract":"Small-scale marine propellers operate at low Reynolds numbers, where laminar-turbulent transition of the boundary layer can impact the distributions of pressure and shear stress on the blade surface. Marine propellers operating at low Reynolds numbers are subject to laminar-turbulent transition of the boundary layer, which impacts the distributions of pressure and shear stress on the blade surface. To design efficient propellers for operation at low Reynolds numbers, transitional effects must be included in the evaluations of propeller performance. In this work, transition modeling techniques in Reynolds Averaged Navier-Stokes computational fluid dynamics (RANS CFD) are utilized to evaluate and design propellers operating at low Reynolds numbers. The Galilean invariant γ transition model with an extension for crossflow transition is coupled to the SSG (Speziale, Sarkar, Gatski) /LRR (Launder, Reece, Rodi) -ω Reynolds stress transport turbulence model, with validation cases performed for flate plate boundary layers, 2-dimensional airfoils, a 3-dimensional wing, and 6:1 prolate spheroids. The performance of the coupled SSG/LRR-ω-γ Reynolds stress transition model for propellers with flow transition is then evaluated using experimental surface streamline and force data from four model-scale marine propellers. A method for the design of low Reynolds number marine propellers is presented using a transition-sensitive lifting line method coupled with the panel method code XFOIL. Initial geometries generated using the lifting-line method are then optimized in RANS CFD using the 2 equation γ-Reθ transition model and an adjoint method to warp the propeller shape to improve the efficiency. Two design studies are performed, including an open water propeller, and a propeller designed for a small autonomous underwater vehicle.","abstract_html":"Small-scale marine propellers operate at low Reynolds numbers, where laminar-turbulent transition of the boundary layer can impact the distributions of pressure and shear stress on the blade surface. Marine propellers operating at low Reynolds numbers are subject to laminar-turbulent transition of the boundary layer, which impacts the distributions of pressure and shear stress on the blade surface. To design efficient propellers for operation at low Reynolds numbers, transitional effects must be included in the evaluations of propeller performance. In this work, transition modeling techniques in Reynolds Averaged Navier-Stokes computational fluid dynamics (RANS CFD) are utilized to evaluate and design propellers operating at low Reynolds numbers. The Galilean invariant γ transition model with an extension for crossflow transition is coupled to the SSG (Speziale, Sarkar, Gatski) /LRR (Launder, Reece, Rodi) -ω Reynolds stress transport turbulence model, with validation cases performed for flate plate boundary layers, 2-dimensional airfoils, a 3-dimensional wing, and 6:1 prolate spheroids. The performance of the coupled SSG/LRR-ω-γ Reynolds stress transition model for propellers with flow transition is then evaluated using experimental surface streamline and force data from four model-scale marine propellers. A method for the design of low Reynolds number marine propellers is presented using a transition-sensitive lifting line method coupled with the panel method code XFOIL. Initial geometries generated using the lifting-line method are then optimized in RANS CFD using the 2 equation γ-Reθ transition model and an adjoint method to warp the propeller shape to improve the efficiency. Two design studies are performed, including an open water propeller, and a propeller designed for a small autonomous underwater vehicle.","abstract_has_math":false,"creators":["Webster, John Ackroyd"],"institution":"Virginia Tech","degree_name":"Doctor of Philosophy","degree_level":"doctoral","degree_discipline":"Aerospace Engineering","degree_department":"Aerospace and Ocean Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Neu, Wayne L.","Brizzolara, Stefano"],"committee_members":["Stilwell, Daniel J.","Woolsey, Craig A.","Paterson, Eric G."],"year":2019,"date_issued":"2019-08-12","date_published":"2019-08-12","updated_at":"2026-07-22T22:19:13Z","subjects":["Marine Propulsion","Transition Modeling","Hydrodynamics"],"languages":[],"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:21869"],"render_values":[{"text":"vt_gsexam:21869","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/93038","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Neu, Wayne L.","Brizzolara, Stefano"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Stilwell, Daniel J.","Woolsey, Craig A.","Paterson, Eric G."]},{"key":"dc:contributor.department","label":"Department","values":["Aerospace and Ocean Engineering"]},{"key":"dc:creator","label":"Author","values":["Webster, John Ackroyd"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2019-08-13T08:00:21Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2019-08-13T08:00:21Z"]},{"key":"dc:date.issued","label":"Date","values":["2019-08-12"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Dissertation"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Aerospace Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["doctoral"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Doctor of Philosophy"]},{"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":["Marine Propulsion","Transition Modeling","Hydrodynamics"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"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:21869"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/93038"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Small-scale marine propellers operate at low Reynolds numbers, where laminar-turbulent transition of the boundary layer can impact the distributions of pressure and shear stress on the blade surface. Marine propellers operating at low Reynolds numbers are subject to laminar-turbulent transition of the boundary layer, which impacts the distributions of pressure and shear stress on the blade surface. To design efficient propellers for operation at low Reynolds numbers, transitional effects must be included in the evaluations of propeller performance. In this work, transition modeling techniques in Reynolds Averaged Navier-Stokes computational fluid dynamics (RANS CFD) are utilized to evaluate and design propellers operating at low Reynolds numbers. The Galilean invariant γ transition model with an extension for crossflow transition is coupled to the SSG (Speziale, Sarkar, Gatski) /LRR (Launder, Reece, Rodi) -ω Reynolds stress transport turbulence model, with validation cases performed for flate plate boundary layers, 2-dimensional airfoils, a 3-dimensional wing, and 6:1 prolate spheroids. The performance of the coupled SSG/LRR-ω-γ Reynolds stress transition model for propellers with flow transition is then evaluated using experimental surface streamline and force data from four model-scale marine propellers. A method for the design of low Reynolds number marine propellers is presented using a transition-sensitive lifting line method coupled with the panel method code XFOIL. Initial geometries generated using the lifting-line method are then optimized in RANS CFD using the 2 equation γ-Reθ transition model and an adjoint method to warp the propeller shape to improve the efficiency. Two design studies are performed, including an open water propeller, and a propeller designed for a small autonomous underwater vehicle."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["Small-scale marine propellers exhibit transition from laminar to turbulent flow in the region near the surface of the blades. Regions of laminar and turbulent flow on the blade surface contribute differently to the overall thrust and torque on the propeller. Prediction of flow transition in the design process for small-scale marine propellers can improve the accuracy of the thrust and torque prediction compared to modeling the flow as purely laminar or turbulent. Propeller thrust and torque can be modeled using computational fluid dynamics (CFD) simulations, where transition modeling is accomplished by solving a transport equation for the intermittency γ, which represents the percentage of time the flow in a given location is turbulent. In this work, a transition model is coupled to a high-fidelity full Reynolds stress turbulence model, which solves 6 transport equations to solve for each component of the Reynolds stress tensor. The Reynolds stress tensor represents the turbulent velocity fluctuations in the governing equations solved in the CFD simulation. This coupled transition and turbulence model is then validated using experimental results of flows with a number of different transition mechanisms. The coupled model is then tested with a series of model-scale propellers, with results of the CFD simulations compared to the experimental results. A method for the design of propellers with flow transition is presented which incorporates transition effects. The designs generated by this method are then optimized in a CFD framework which morphs the blade geometry to improve the ratio of the thrust produced by the propeller to the torque, which corresponds to a higher efficiency. Two design cases are presented: a propeller designed for open water operation, and a propeller design for a small autonomous underwater vehicle."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Doctor of Philosophy"]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["ETD"]},{"key":"dc:title","label":"Title","values":["Design and Analysis of Low Reynolds Number Marine Propellers with Computational Fluid Dynamics (CFD) Transition Modeling"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Neu, Wayne L.","Brizzolara, Stefano"],"dc:contributor.committeemember":["Stilwell, Daniel J.","Woolsey, Craig A.","Paterson, Eric G."],"dc:contributor.department":["Aerospace and Ocean Engineering"],"dc:creator":["Webster, John Ackroyd"],"dc:date.accessioned":["2019-08-13T08:00:21Z"],"dc:date.available":["2019-08-13T08:00:21Z"],"dc:date.issued":["2019-08-12"],"dc:description.abstract":["Small-scale marine propellers operate at low Reynolds numbers, where laminar-turbulent transition of the boundary layer can impact the distributions of pressure and shear stress on the blade surface. Marine propellers operating at low Reynolds numbers are subject to laminar-turbulent transition of the boundary layer, which impacts the distributions of pressure and shear stress on the blade surface. To design efficient propellers for operation at low Reynolds numbers, transitional effects must be included in the evaluations of propeller performance. In this work, transition modeling techniques in Reynolds Averaged Navier-Stokes computational fluid dynamics (RANS CFD) are utilized to evaluate and design propellers operating at low Reynolds numbers. The Galilean invariant γ transition model with an extension for crossflow transition is coupled to the SSG (Speziale, Sarkar, Gatski) /LRR (Launder, Reece, Rodi) -ω Reynolds stress transport turbulence model, with validation cases performed for flate plate boundary layers, 2-dimensional airfoils, a 3-dimensional wing, and 6:1 prolate spheroids. The performance of the coupled SSG/LRR-ω-γ Reynolds stress transition model for propellers with flow transition is then evaluated using experimental surface streamline and force data from four model-scale marine propellers. A method for the design of low Reynolds number marine propellers is presented using a transition-sensitive lifting line method coupled with the panel method code XFOIL. Initial geometries generated using the lifting-line method are then optimized in RANS CFD using the 2 equation γ-Reθ transition model and an adjoint method to warp the propeller shape to improve the efficiency. Two design studies are performed, including an open water propeller, and a propeller designed for a small autonomous underwater vehicle."],"dc:description.abstractgeneral":["Small-scale marine propellers exhibit transition from laminar to turbulent flow in the region near the surface of the blades. Regions of laminar and turbulent flow on the blade surface contribute differently to the overall thrust and torque on the propeller. Prediction of flow transition in the design process for small-scale marine propellers can improve the accuracy of the thrust and torque prediction compared to modeling the flow as purely laminar or turbulent. Propeller thrust and torque can be modeled using computational fluid dynamics (CFD) simulations, where transition modeling is accomplished by solving a transport equation for the intermittency γ, which represents the percentage of time the flow in a given location is turbulent. In this work, a transition model is coupled to a high-fidelity full Reynolds stress turbulence model, which solves 6 transport equations to solve for each component of the Reynolds stress tensor. The Reynolds stress tensor represents the turbulent velocity fluctuations in the governing equations solved in the CFD simulation. This coupled transition and turbulence model is then validated using experimental results of flows with a number of different transition mechanisms. The coupled model is then tested with a series of model-scale propellers, with results of the CFD simulations compared to the experimental results. A method for the design of propellers with flow transition is presented which incorporates transition effects. The designs generated by this method are then optimized in a CFD framework which morphs the blade geometry to improve the ratio of the thrust produced by the propeller to the torque, which corresponds to a higher efficiency. Two design cases are presented: a propeller designed for open water operation, and a propeller design for a small autonomous underwater vehicle."],"dc:description.degree":["Doctor of Philosophy"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:21869"],"dc:identifier.uri":["http://hdl.handle.net/10919/93038"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Marine Propulsion","Transition Modeling","Hydrodynamics"],"dc:title":["Design and Analysis of Low Reynolds Number Marine Propellers with Computational Fluid Dynamics (CFD) Transition Modeling"],"dc:type":["Dissertation"],"thesis:degree_discipline":["Aerospace Engineering"],"thesis:degree_level":["doctoral"],"thesis:degree_name":["Doctor of Philosophy"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:13Z"}