{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/137553"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/137553","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Assessment of RANS Turbulence Models for Hypersonic Flat Plates","abstract":"Many hypersonic flow applications have cold walls, where the wall temperature is significantly less than the recovery, or adiabatic, temperature. Current Reynolds-Averaged Navier-Stokes and Favre-Averaged Navier-Stokes approaches using linear eddy viscosity models for turbulence were not designed and optimized with hypersonic flow problems in mind, and thus have weaknesses that are continuously being studied and addressed. This study evaluates the performance of the Menter Shear Stress Transport (SST) and Spalart–Allmaras (SA) models on a group of hypersonic flat plate cases from a recent direct numerical simulation (DNS) database. Quantities of interest examined include velocity, temperature, turbulent kinetic energy, modeled turbulent kinetic energy budget terms, eddy viscosity, Reynolds stresses, heat fluxes, wall skin friction, wall heat transfer, and Reynolds analogy factor. Generally, the SA model performs better than the SST model in capturing the quantities of interest, but higher Mach number can occasionally reduce the accuracy of SA. Both models generally have increased errors in the quantities of interest with lower temperature ratio, with the SST model having a considerable sensitivity to lower temperature ratio. SST significantly underpredicts turbulent kinetic energy, fails at predicting key turbulent kinetic energy budget terms, and the Boussinesq approximation fails in capturing Reynolds normal stresses. For wall quantities, both models generally have increased errors at the lowest and highest Reynolds numbers studied, with the skin friction having increased errors with lower temperature ratio.","abstract_html":"Many hypersonic flow applications have cold walls, where the wall temperature is significantly less than the recovery, or adiabatic, temperature. Current Reynolds-Averaged Navier-Stokes and Favre-Averaged Navier-Stokes approaches using linear eddy viscosity models for turbulence were not designed and optimized with hypersonic flow problems in mind, and thus have weaknesses that are continuously being studied and addressed. This study evaluates the performance of the Menter Shear Stress Transport (SST) and Spalart–Allmaras (SA) models on a group of hypersonic flat plate cases from a recent direct numerical simulation (DNS) database. Quantities of interest examined include velocity, temperature, turbulent kinetic energy, modeled turbulent kinetic energy budget terms, eddy viscosity, Reynolds stresses, heat fluxes, wall skin friction, wall heat transfer, and Reynolds analogy factor. Generally, the SA model performs better than the SST model in capturing the quantities of interest, but higher Mach number can occasionally reduce the accuracy of SA. Both models generally have increased errors in the quantities of interest with lower temperature ratio, with the SST model having a considerable sensitivity to lower temperature ratio. SST significantly underpredicts turbulent kinetic energy, fails at predicting key turbulent kinetic energy budget terms, and the Boussinesq approximation fails in capturing Reynolds normal stresses. For wall quantities, both models generally have increased errors at the lowest and highest Reynolds numbers studied, with the skin friction having increased errors with lower temperature ratio.","abstract_has_math":false,"creators":["Vaughan, Joshua Clinton"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Aerospace Engineering","degree_department":"Aerospace and Ocean Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Roy, Christopher John"],"committee_members":["Massa, Luca","Lowe, Kevin T."],"year":2025,"date_issued":"2025-08-21","date_published":"2025-08-21","updated_at":"2026-07-22T22:18:58Z","subjects":["Turbulence Modeling","CFD","Hypersonic","Cold-Wall","Flat Plate"],"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:44415"],"render_values":[{"text":"vt_gsexam:44415","href":null,"code":true}]}]},"links":{"outbound_url":"https://hdl.handle.net/10919/137553","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Roy, Christopher John"]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Massa, Luca","Lowe, Kevin T."]},{"key":"dc:contributor.department","label":"Department","values":["Aerospace and Ocean Engineering"]},{"key":"dc:creator","label":"Author","values":["Vaughan, Joshua Clinton"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2025-08-22T08:00:22Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2025-08-22T08:00:22Z"]},{"key":"dc:date.issued","label":"Date","values":["2025-08-21"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Aerospace 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":["Turbulence Modeling","CFD","Hypersonic","Cold-Wall","Flat Plate"]}]},{"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:44415"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://hdl.handle.net/10919/137553"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Many hypersonic flow applications have cold walls, where the wall temperature is significantly less than the recovery, or adiabatic, temperature. Current Reynolds-Averaged Navier-Stokes and Favre-Averaged Navier-Stokes approaches using linear eddy viscosity models for turbulence were not designed and optimized with hypersonic flow problems in mind, and thus have weaknesses that are continuously being studied and addressed. This study evaluates the performance of the Menter Shear Stress Transport (SST) and Spalart–Allmaras (SA) models on a group of hypersonic flat plate cases from a recent direct numerical simulation (DNS) database. Quantities of interest examined include velocity, temperature, turbulent kinetic energy, modeled turbulent kinetic energy budget terms, eddy viscosity, Reynolds stresses, heat fluxes, wall skin friction, wall heat transfer, and Reynolds analogy factor. Generally, the SA model performs better than the SST model in capturing the quantities of interest, but higher Mach number can occasionally reduce the accuracy of SA. Both models generally have increased errors in the quantities of interest with lower temperature ratio, with the SST model having a considerable sensitivity to lower temperature ratio. SST significantly underpredicts turbulent kinetic energy, fails at predicting key turbulent kinetic energy budget terms, and the Boussinesq approximation fails in capturing Reynolds normal stresses. For wall quantities, both models generally have increased errors at the lowest and highest Reynolds numbers studied, with the skin friction having increased errors with lower temperature ratio."]},{"key":"dc:description.abstractgeneral","label":"General Abstract","values":["Hypersonic flow is characterized by a flow speed of five times greater or more than the speed of sound. Because the flow moves at such high speed, interesting flow phenomena can occur. Vehicles and bodies that move at hypersonic speeds usually have cold walls, where there is considerable heat transfer to their surfaces. Currently, fluid dynamicists use computational fluid dynamics (CFD) to simulate vehicles or bodies in hypersonic flow. However, the approaches most currently used have many weaknesses, and fluid dynamicists are continuously studying and addressing them. This study looks at two of the most used turbulence models that fluid dynamicists use for CFD, to see how well the models do when simulating a flat plate moving at hypersonic speed with a cold wall. The CFD results using the two turbulence models are compared to a set of data produced by another CFD method that is able to capture the turbulence more realistically than the two turbulence models can. Generally, the two turbulence models fail to capture key quantities of interest important to fluid dynamicists, and there are various components within the models that could be improved. Additionally, having a cold wall generally leads to greater innacuracy in the CFD results using the two turbulence models. The results produced and observations made in this study could lead to corrections for, or better approaches than, the two turbulence models studied."]},{"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":["Assessment of RANS Turbulence Models for Hypersonic Flat Plates"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Roy, Christopher John"],"dc:contributor.committeemember":["Massa, Luca","Lowe, Kevin T."],"dc:contributor.department":["Aerospace and Ocean Engineering"],"dc:creator":["Vaughan, Joshua Clinton"],"dc:date.accessioned":["2025-08-22T08:00:22Z"],"dc:date.available":["2025-08-22T08:00:22Z"],"dc:date.issued":["2025-08-21"],"dc:description.abstract":["Many hypersonic flow applications have cold walls, where the wall temperature is significantly less than the recovery, or adiabatic, temperature. Current Reynolds-Averaged Navier-Stokes and Favre-Averaged Navier-Stokes approaches using linear eddy viscosity models for turbulence were not designed and optimized with hypersonic flow problems in mind, and thus have weaknesses that are continuously being studied and addressed. This study evaluates the performance of the Menter Shear Stress Transport (SST) and Spalart–Allmaras (SA) models on a group of hypersonic flat plate cases from a recent direct numerical simulation (DNS) database. Quantities of interest examined include velocity, temperature, turbulent kinetic energy, modeled turbulent kinetic energy budget terms, eddy viscosity, Reynolds stresses, heat fluxes, wall skin friction, wall heat transfer, and Reynolds analogy factor. Generally, the SA model performs better than the SST model in capturing the quantities of interest, but higher Mach number can occasionally reduce the accuracy of SA. Both models generally have increased errors in the quantities of interest with lower temperature ratio, with the SST model having a considerable sensitivity to lower temperature ratio. SST significantly underpredicts turbulent kinetic energy, fails at predicting key turbulent kinetic energy budget terms, and the Boussinesq approximation fails in capturing Reynolds normal stresses. For wall quantities, both models generally have increased errors at the lowest and highest Reynolds numbers studied, with the skin friction having increased errors with lower temperature ratio."],"dc:description.abstractgeneral":["Hypersonic flow is characterized by a flow speed of five times greater or more than the speed of sound. Because the flow moves at such high speed, interesting flow phenomena can occur. Vehicles and bodies that move at hypersonic speeds usually have cold walls, where there is considerable heat transfer to their surfaces. Currently, fluid dynamicists use computational fluid dynamics (CFD) to simulate vehicles or bodies in hypersonic flow. However, the approaches most currently used have many weaknesses, and fluid dynamicists are continuously studying and addressing them. This study looks at two of the most used turbulence models that fluid dynamicists use for CFD, to see how well the models do when simulating a flat plate moving at hypersonic speed with a cold wall. The CFD results using the two turbulence models are compared to a set of data produced by another CFD method that is able to capture the turbulence more realistically than the two turbulence models can. Generally, the two turbulence models fail to capture key quantities of interest important to fluid dynamicists, and there are various components within the models that could be improved. Additionally, having a cold wall generally leads to greater innacuracy in the CFD results using the two turbulence models. The results produced and observations made in this study could lead to corrections for, or better approaches than, the two turbulence models studied."],"dc:description.degree":["Master of Science"],"dc:format.medium":["ETD"],"dc:identifier.other":["vt_gsexam:44415"],"dc:identifier.uri":["https://hdl.handle.net/10919/137553"],"dc:language.iso":["en"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Turbulence Modeling","CFD","Hypersonic","Cold-Wall","Flat Plate"],"dc:title":["Assessment of RANS Turbulence Models for Hypersonic Flat Plates"],"dc:type":["Thesis"],"thesis:degree_discipline":["Aerospace Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:18:58Z"}