Numerical Prediction of Laminar-to-Turbulent Transition Around the Prolate Spheroid
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RESEARCH ARTICLE
Numerical Prediction of Laminar-to-Turbulent Transition Around the Prolate Spheroid Erfan Kadivar 1 & Ebrahim Kadivar 2 & Seyed Morteza Javadpour 3 Received: 26 November 2019 / Accepted: 6 June 2020 # Harbin Engineering University and Springer-Verlag GmbH Germany, part of Springer Nature 2020
Abstract In this work, the laminar-to-turbulent transition phenomenon around the two- and three-dimensional ellipsoid at different Reynolds numbers is numerically investigated. In the present paper, Reynolds Averaged Navier Stokes (RANS) equations with the Spalart-Allmaras, SST k − ω, and SST-Trans models are used for numerical simulations. The possibility of laminar-toturbulent boundary layer transition is summarized in phase diagrams in terms of skin friction coefficient and Reynolds number. The numerical results show that SST-Trans method can detect different aspects of flow such as adverse pressure gradient and laminar-to-turbulent transition onset. Our numerical results indicate that the laminar-to-turbulent transition location on the 6:1 prolate spheroid is in a good agreement with the experimental data at high Reynolds numbers. Keywords Laminar-to-turbulent transition . Shear stress transport turbulence model . Skin fraction . Three-dimensional ellipsoid
1 Introduction Understanding and predicting the behavior of laminar to turbulence transition is one of the important topics in the aerospace and marine engineering. The prediction of the drag force, lift loss, and fluctuations in the pressure field Highlights • Laminar-to-turbulent transition phenomenon around the two- and threedimensional ellipsoid at different Reynolds numbers is numerically studied. • The k−ω SST, Spalart-Allmaras, and SST-Trans models are used to perform RANS simulations. • The numerical results show that SST-Trans method can detect different aspects of flow such as adverse pressure gradient and laminar-toturbulent transition onset. • Numerical results indicate that the laminar-to-turbulent transition location on the 6:1 prolate spheroid is in a good agreement with the experimental data at high Reynolds numbers. * Erfan Kadivar [email protected] 1
Department of Physics, Shiraz University of Technology, Shiraz 71555-313, Iran
2
Institute of Ship Technology, Ocean Engineering and Transport Systems, University of Duisburg-Essen, 47057 Duisburg, Germany
3
Department of Mechanical Engineering, University of Gonabad, Gonabad, Iran
around a body are difficult. Turbulent flow around a geometrically simple and complicated shapes over a wide range of Reynolds numbers has been performed experimentally and numerically. Taneda has experimentally investigated the steady wake behind a sphere at low Reynolds numbers (Taneda 1956). His results indicate that flow around the sphere is perfectly laminar at the Reynolds numbers less than 24. The experimental results indicate that for Reynolds numbers less than 24, the flow around the sphere is perfectly laminar (Taneda 1956). Therefore, there is no flow separation, and the flow stream
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