Assessment of direct numerical simulation data of turbulent boundary layers

• Published in: Journal of fluid mechanics Vol. 659; pp. 116 - 126
• Main Authors: SCHLATTER, PHILIPP, ÖRLÜ, RAMIS
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 25.09.2010
• Subjects: Boundary conditions; Boundary layer; Boundary layer and shear turbulence; Boundary layers; Computer simulation; Engineering mechanics; Exact sciences and technology; Fluid dynamics; Fluid flow; Fluid mechanics; Friction; Fundamental areas of phenomenology (including applications); Inflow; Mathematical models; Numerical analysis; Physics; Statistical analysis; Strömningsmekanik; TECHNOLOGY; TEKNIKVETENSKAP; Teknisk mekanik; Turbulence; turbulence simulation; Turbulence simulation and modeling; Turbulent boundary layer; turbulent boundary layers; Turbulent flow; Turbulent flows, convection, and heat transfer; turbulent boundary layers; turbulence simulation; Turbulent flow; Skin friction; Digital simulation; Modelling; Velocity distribution; Form factors; Boundary layers; Turbulence structure
• ISSN: 0022-1120; 1469-7645; 1469-7645
• DOI: 10.1017/S0022112010003113

Statistics obtained from seven different direct numerical simulations (DNSs) pertaining to a canonical turbulent boundary layer (TBL) under zero pressure gradient are compiled and compared. The considered data sets include a recent DNS of a TBL with the extended range of Reynolds numbers Reθ = 500–4300. Although all the simulations relate to the same physical flow case, the approaches differ in the applied numerical method, grid resolution and distribution, inflow generation method, boundary conditions and box dimensions. The resulting comparison shows surprisingly large differences not only in both basic integral quantities such as the friction coefficient cf or the shape factor H12, but also in their predictions of mean and fluctuation profiles far into the sublayer. It is thus shown that the numerical simulation of TBLs is, mainly due to the spatial development of the flow, very sensitive to, e.g. proper inflow condition, sufficient settling length and appropriate box dimensions. Thus, a DNS has to be considered as a numerical experiment and should be the subject of the same scrutiny as experimental data. However, if a DNS is set up with the necessary care, it can provide a faithful tool to predict even such notoriously difficult flow cases with great accuracy.