Wing-Body Junction Flow

A three dimensional, pressure driven turbulent boundary layer created by a wing-body junction flow was experimentally studied. The geometry is shown in figure 1.

Fig. 1: Flow geometry

The wing used was a 3:2, semi-elliptical nosed NACA 0020 tailed symmetric profile which has a chord length of 30.5 cm (12 in.), maximum thickness of 7.17 cm (2.824 in.), and height of 22.9 cm (9.016 in.). The wing was mounted on the centreline of the flat plate wind tunnel floor. The nominal reference velocity of the flow was 27.5 m/s and the Reynolds number based on the momentum thickness at 0.75 chord upstream of the wing on the centreline of the tunnel and wing was \(Re_{\theta} = 5936\).

The data available includes the mean velocity and all Reynolds stresses at several (\(x\), \(z\)) stations on a line determined by translating in the direction of the mean velocity vector component parallel to the wall in the layer where the \(\overline{u^2}\) normal stress is maximum. Time-mean static pressure at a number of locations on the base wall and wing surface was also measured.

Data were obtained both with hot-wire (HW, at 24 stations) and laser Doppler-velocimeter (LDV, at 8 stations) techniques. The locations of these traverses are shown in figure 2. The incoming boundary layer was also measured at 15 different stations located at a distance of 0.75 chord upstream of the wing across half of the tunnel test section.

Fig. 2: Hot wire and LDV measurement points (circles and triangles: hot wire points; crosses: LDV points)

The LDV measurements were taken twice due to the differences observed between the HW and the LDV data. The uncertainties in the mean velocity and the stresses were examined extensively.

Data available include:

• Pressure coefficient measurements on the flat base wall and wing surface
• Mean velocity and Reynolds stress profiles measured by hot-wire and LDV at a number of \((x,z)\) locations

Sample plots of selected quantities are available.

The data can be downloaded as compressed archives from the links below, or as individual files.

• wbjf-allfiles.zip
• wbjf-allfiles.tar.gz

The file readme.txt has information on the data file naming and contents.

Pressure coefficients:

LDV and hot-wire profiles:
Other than for the upstream locations, three files are given for each profile, corresponding to the velocities being expressed in three different coordinate systems. “tc” denotes Tunnel Coordinates, where the \(x\)-axis is along the symmetry line of the wing. “fs” denotes Free-Stream Coordinates, where the positive \(x\)-axis is in the direction of the mean velocity at the boundary layer edge. “ns” denotes Normal Stress Coordinates, where the positive \(x\)-axis is in the direction of the local mean velocity vector parallel to the tunnel floor at the \(y\) location where the normal stress \(\overline{u^2}\) is maximum.

1. Ölçmen, M.S., Simpson, R.L. (1992). Perspective: On the near wall similarity of three-dimensional turbulent boundary layers. Journal of Fluids Engineering, Vol. 114, pp. 487-495.
2. Ölçmen, S.M., Simpson, R.L. (1995). An experimental study of a three-dimensional pressure-driven turbulent boundary layer. J. Fluid Mech., Vol. 290, pp. 225-262.

Indexed data: