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dc.contributor.authorPont Vilchez, Arnau
dc.contributor.authorTrias Miquel, Francesc Xavier
dc.contributor.authorGorobets, Andrey
dc.contributor.authorOliva Llena, Asensio
dc.contributor.otherUniversitat Politècnica de Catalunya. Departament de Màquines i Motors Tèrmics
dc.identifier.citationPont, A. [et al.]. Direct numerical simulation of backward-facing step flow at Ret = 395 and expansion ratio 2. "Journal of fluid mechanics", 25 Març 2019, vol. 863, p. 341-363.
dc.description.abstractBackward-facing step (BFS) constitutes a canonical configuration to study wallbounded flows subject to massive expansions produced by abrupt changes in geometry. Recirculation flow regions are common in this type of flow, driving the separated flow to its downstream reattachment. Consequently, strong adverse pressure gradients arise through this process, feeding flow instabilities. Therefore, both phenomena are strongly correlated as the recirculation bubble shape defines how the flow is expanded, and how the pressure rises. In an incompressible flow, this shape depends on the Reynolds value and the expansion ratio. The influence of these two variables on the bubble length is widely studied, presenting an asymptotic behaviour when both parameters are beyond a certain threshold. This is the usual operating point of many practical applications, such as in aeronautical and environmental engineering. Several numerical and experimental studies have been carried out regarding this topic. The existing simulations considering cases beyond the above-mentioned threshold have only been achieved through turbulence modelling, whereas direct numerical simulations (DNS) have been performed only at low Reynolds numbers. Hence, despite the great importance of achieving this threshold, there is a lack of reliable numerical data to assess the accuracy of turbulence models. In this context, a DNS of an incompressible flow over a BFS is presented in this paper, considering a friction Reynolds number (Reτ) of 395 at the inflow and an expansion ratio 2. Finally, the elongation of the Kelvin–Helmholtz instabilities along the shear layer is also studied.
dc.format.extent23 p.
dc.subjectÀrees temàtiques de la UPC::Enginyeria mecànica::Mecànica de fluids
dc.subject.lcshTurbulence--Simulation methods
dc.subject.otherShear layer turbulence
dc.subject.otherTurbulence simulation
dc.subject.otherTurbulent convection
dc.titleDirect numerical simulation of backward-facing step flow at Ret = 395 and expansion ratio 2
dc.subject.lemacTurbulència -- Simulació numèrica
dc.contributor.groupUniversitat Politècnica de Catalunya. CTTC - Centre Tecnològic de la Transferència de Calor
dc.rights.accessOpen Access
dc.description.versionPostprint (published version)
local.citation.authorPont, A.; Trias, F. X.; Gorobets, A.; Assensi, O.
local.citation.publicationNameJournal of fluid mechanics

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