Journal of Fluid Mechanics

Papers

Assessment of direct numerical simulation data of turbulent boundary layers

PHILIPP SCHLATTERa1 c1 and RAMIS ÖRLÜa1

a1 Linné Flow Centre, KTH Mechanics, SE-100 44 Stockholm, Sweden

Abstract

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.

(Received February 17 2010)

(Revised June 07 2010)

(Accepted June 07 2010)

(Online publication July 16 2010)

Key words:

  • turbulent boundary layers;
  • turbulence simulation

Correspondence:

c1 Email address for correspondence: pschlatt@mech.kth.se

Metrics
Related Content