Calculation of three-dimensional turbulent boundary layers

Journal of Fluid Mechanics, 1995

A three-dimensional, pressure-driven turbulent boundary layer created by an idealized wing–body junction flow was studied experimentally. The data presented include time-mean static pressure and directly measured skin-friction magnitude on the wall. The mean velocity and all Reynolds stresses from a three-velocity-component fibre-optic laser-Doppler anemometer are presented at several stations along a line determined by the mean velocity vector component parallel to the wall in the layer where the $\overline{u^2}$ kinematic normal stress is maximum (normal-stress coordinate system). This line was selected by intuitively reasoning that overlap of the near-wall flow and outer-region flow occurs at the location where $\overline{u^2}$ is maximum. Along this line the flow is subjected to a strong crossflow pressure gradient, which changes sign for the downstream stations. The shear-stress vector direction in the flow lags behind the flow gradient vector direction. The flow studied here d...

28th Fluid Dynamics Conference, 1997

The paper describes the results of an extensive experimental investigation of the three-dimensional turbulent boundary-layers on both sides of a swept wing and its wake. Although the experiment was carried out at low speed, the shape of the wing was designed such as to obtain flow conditions resembling those on practical transonic swept wings, with emphasis on the three-dimensionality of the viscous flow. Mean velocity profiles were determined at nearly 300 stations, while full 3D turbulence measurements were executed at over 200 stations. A special and probably unique feature is that a c omplete independent check was obtained by executing measurements at the same Reynolds number on two scaled test setups in two wind tunnels (the ONERA-F2 and the NLR-LST) using a number of different measurement techniques. This fact, together with an extensive error-analysis, has contributed significantly to the reliability of the experimental data and also gives an impression of the uncertainty range of the data. The work was carried out within the GARTEUR framework as a collaborative effort by DERA, DLR, FFA, NLR and ONERA/CERT.

2006

1972

Three-dimensional, compressible turbulent boundary-layer calculations have been performed for the finite supercritical wing of the NASA modified F8 transonic research airplane. Data on the boundary-layer thickness, displacement thickness, skin friction components, and integrated streamwise skin friction are presented for points along the streamwise stations of which the pressure measurements were previously made. Representative velocity profiles are shown, and boundary-layer-thickness contour plots and skin-friction vector plots are presented. Results are given for a Reynolds number of 1.5 million per foot, and for Mach numbers of 0.50 and 0.99.

2014

Due to a singularity in the governing three-dimensional turbulent momentum integral equations at the attachment line, low order infinite-swept and swept-tapered CFD methods employing the viscous-coupling technique have been unable to model attachment line transition or contamination without approximating the development of the boundary layer immediately downstream of a turbulent attachment line. An experimental study was therefore conducted to explore the flow near a turbulent attachment line, which showed considerable differences to the numerical approximation. On the basis of the experimental data; a modification to the governing equations in the attachment line region has been proposed and tested. Comparisons with experimental measurements show that the proposed numerical model is not only able to predict the flow to within ±5%, but it also captures the non-monotonic behaviour of the momentum thickness, in the vicinity of the attachment line, which has not been reported previously.

Final Report, 1981

Journal of Fluid Mechanics, 2007

The Stokes boundary layer in the turbulent regime is investigated by using large-eddy simulations (LES). The Reynolds number, based on the thickness of the Stokes boundary layer, is set equal to Re δ = 1790, which corresponds to test 8 of the experimental study of Jensen et al. (J. Fluid Mech. vol. 206, 1989, p. 265).

Progress in Computational Fluid Dynamics, 2008

This study is about the behaviour of a two dimensional turbulent boundary layer on a flat plate subjected to a transverse motion of the bounding wall, producing a sudden shear force. The resulted flow is three-dimensional. Numerical prediction is achieved using the k-ε model at high Reynolds number with the assumption of an isotropic turbulent viscosity. Close wall treatment constitutes the main difficulty within the three-dimensional turbulent boundary layer modelling. Therefore, we propose a law of wall along the transverse direction. Whilst the standard logarithmic function suggested in the literature for the two-dimensional case is used for the longitudinal component.

Journal of Fluid Mechanics, 1972

The importance of fluctuating turbulent stresses in the flow over a wave is examined. It is shown that anisotropic stresses, which are most likely to be turbulent Reynolds stresses, are essential to the process of energy flow to the wave. Two fundamentally different methods of predicting fluctuating turbulent Reynolds stresses are examined. One method makes use of a phenomenological closure of the conservation equation for the turbulent Reynolds stresses and is similar to the turbulent boundary-layer calculation scheme of Bradshaw, Ferriss & Atwell (1967). The second method is based on the assumption that the turbulent stresses are determined by the recent history of velocity shear experienced by a fluid parcel and results in a viscoelastic constitutive relation for the turbulence; in the limit of shortest 'memory' this relation becomes the eddy viscosity model proposed by . Comparison of predicted and measured values of surface pressure indicates that the eddy viscoelasticity model can explain measured pressure distributions but the comparison is not conclusive. Suggestions for further measurements are made.

Jetp Letters, 2006

Turbulent boundary layers exhibit a universal structure that nevertheless is rather complex and is composed of a viscous sublayer, a buffer zone, and a turbulent log-law region. In this letter, we present a simple analytic model of turbulent boundary layers that culminates in explicit formulas for the profiles of the mean velocity, the kinetic energy, and the Reynolds stress as a function of the distance from the wall. The resulting profiles are in close quantitative agreement with measurements over the entire structure of the boundary layer without any need of refitting in the different zones.