Analysts Information

BSCW Analysis

Information necessary to analyze this configuration:

  • Geometry
  • Grids
  • Background information
  • Analysis conditions

Experimental Data


Wind tunnel tests were conducted at NASA Transonic Dynamics Tunnel of the Benchmark Supercritical Wing as part of the checkout of the Oscillating TurnTable (OTT); TDT Test 548, August 2000, conducted by Dave Piatak et al. Original testing of this model was performed under the Benchmark Models Program using a Pitch and Plunge Apparatus (PAPA) mounting system; TDT Test 470, 1992, by Bennett et al; performed testing in both in Air and R-12 test media,

Results from AePW

BSCW AePW Results

The results generated by the analysis teams are described and assembled into a MATLAB database. These results are compared with the experimental data. The principal results are unforced system pressure distributions and frequency response function magnitude and phase diagrams at the excitation frequencies.

AePW Selection Rationale

The BSCW cases were chosen for inclusion in the AePW to focus on the steady and unsteady aerodynamic solutions of a seemingly simple geometry where the complexity of the flow field advanced from the pre-workshop evaluation of the "relatively simple flow field associated with the RSW." Here, it was anticipated that the flow field would include moderate separation effects for the test cases chosen: Mach 0.85, 5° mean angle of attack. As in the RSW case, two frequencies of oscillation were chosen to evaluate the influence of reduced frequency.
The Benchmark Supercritical Wing (BSCW) was chosen as the second configuration to study due to its geometric simplicity, and flow field complexity at transonic conditions. This data set was obtained recently enough so that the raw experimental data is still available.

Wind Tunnel Model The BSCW airfoil is a supercritical SC(2)-0414. The airfoil designation indicates that it was part of the 2nd generation of designed supercritical airfoils, with a design normal force coefficient of 0.4 and a 14&percent; thickness to chord ratio. The planform is rectangular with a wing tip cap shaped as a tip of revolution. The model pitch axis was located at the 30&percent; chord. The boundary layer transition was fixed for hte OTT testing, using #30 grid, applied at 7.5&percent; chord to the upper and lower wing surfaces.

Wind Tunnel Test Matrix For the OTT test in the TDT, data was acquired in an R-134a test medium at Mach numbers ranging from 0.40 to 0.87, dynamic pressures (q) of 100 to 200 psf, and angles of attack from -1 to 5 degs. Unforced system "steady" data was obtained with the model held at a fixed angle of attack; Forced pitching oscillation data was acquired for pitch frequencies between 1 and 30 Hz, in most cases with an amplitude of 1°.

Computations and Results Summary The BSCW case served as a semi-blind test case for the AePW. There were very small plot of some of the data previously published, but in insufficient detail to be truly useful to the analysis teams. Eight teams performed analyses of the BSCW; they used Reynolds-Averaged Navier-Stokes flow solvers exercised assuming that the wing had a rigid structure. Both steady-state and forced oscillation computations were performed by each team, with some teams choosing to perform time-accurate simulations even for the unforced system case. The results of these calculations were compared with each other and with the experimental data. The steady-state results from the computations capture many of the flow features of a classical supercritical airfoil pressure distribution. The most dominant feature of the oscillatory results is the upper surface shock dynamics. Substantial variations were observed among the computational solutions as well as differences relative to the experimental data. Follow-on studies have included hybrid RANS-LES simulations.

RSW geometry

RSW airfoil