WIND TUNNEL DATA

4th AIAA CFD High Lift Prediction Workshop

Wind tunnel data (from the QinetiQ Five-Meter Pressurized Low-Speed Wind Tunnel in Farnborough, UK) are provided here:

• Forces and Moments: Exp_Forces_Moments_v2.tar.gz <- modified 07/27/2021 (data from off-nominal flap angles added)
  • The wind tunnel polar data was obtained using a pitch-pause approach, increasing AoA from one angle to the next with rotation speed of roughly 0.2 deg/sec. When pausing at each AoA, a human-in-the-loop waited for the tunnel to attain the correct Q and Mach number and for the balance to stabilize. Then, the data were taken and averaged over a 5 second window. On average, this whole period was roughly 30 seconds for each AoA (move, stabilize, acquire).
  • To correct the wind tunnel data to free-air conditions, the QinetiQ tunnel used "Ashill's Wall Pressure Method" for flow angularity.
  • Hysteresis was not explored/documented in the QinetiQ test.
  • The model's standoff did not contribute to the balance data's measured forces or moment.
• Surface Mini-Tuft Photos: Mini_Tuft_v2.tar.gz <- modified 07/23/2021 (data from off-nominal flap angles added)
• Surface Oil Flow Photos: Oil_Flow.tar.gz
  • All oil flows were obtained corresponding to the C_L levels provided in the force and moment data files. Hysteresis was not explored in this test, but it is possible that different-looking oil flow patterns could have been attained by bringing the tunnel up to conditions in a different way. In all cases, oil flows should be considered to be a qualitative measure only, because of effects of oil thickness, viscosity, drying time, etc.
• Surface Pressures (all data in full-scale coordinates, inches): <- modified 07/27/2021 (data from off-nominal flap angles added)

  Flap configuration	Excel file	Tecplot-readable column format
  Nominal 40/37	Run266_Pressure_Data_mod_04_2021.xlsx	Run266_crm-hl_modelcp_40-37_mod_04_2021.dat
  37/34, corrected AoA=7.014 deg only	Run268_Pressure_Data_orig.xlsx	Run268_crm-hl_modelcp_37-34.dat
  43/40, corrected AoA=7.062 deg only	Run270_Pressure_Data_orig.xlsx	Run270_crm-hl_modelcp_43-40.dat

  • See Data Submittal Forms & Postprocessing Info page for details regarding how to extract the deployed pressure tap locations
  • The Cps themselves are not corrected for wind tunnel effects; the only correction comes through the angle of attack
  • Note that the AoAs where Cp data were taken for the off-nominal configurations were slightly different than those for the nominal case. The effect of these small AoA differences are expected to be insignificant.
• Floor Rake Data:
  • R266RakeData_v2.xlsx <- new as of 03/17/2021
  • ΔCp_t = (P_t,probe - P_t,ref) / Q_ref provided as a function of height in the QinetiQ tunnel
  • Height given both in mm (for actual tunnel) and in inches (for "scaled up" version of tunnel that is 10x the actual size)
  • BL Rake is on the floor of the tunnel upstream of the model; see details on GEOMETRY FILES page
• Model Boundary-Layer Tripping Information:
  • Provided on the GEOMETRY FILES page

Note: there is no information on the particular camera positions used for taking the various oil flow and mini-tuft photos.
 
 

Please check periodically for updates, and/or get on the email distribution list by request to hiliftpw@gmail.com to be notified directly of any updates/changes.

Note 1: related AIAA papers on the HLPW-4 CRM-HL testing and configuration are: AIAA-2020-2770 and AIAA-2020-2771 (also mentioned on the Geometries page).

Note 2: the same wind tunnel test article, with slightly different configuration settings, was tested earlier in the NASA Langley 14x22 wind tunnel (which also involved separate flow control investigations). This 14x22 test was at a lower Reynolds number (3.27 x 10⁶ per mean aerodynamic chord) than the QinetiQ case being used for HLPW4 (5.49 x 10⁶). Because the reference case in the 14x22 test involved a different RE_MAC and slightly different configuration settings, it is not appropriate to make direct comparisons to the 14x22 data using the current HLPW-4 provided geometry. Nevertheless, participants may be interested to see documentation of the earlier wind tunnel results: AIAA-2019-3723, AIAA-2019-3727, AIAA-2020-0786.

Return to: High Lift Prediction Workshop Home Page

Recent Significant Site Updates
07/27/2021 - Added force/moment and Cp data for off-nominal flap angles
07/23/2021 - Added v2 of mini-tuft data, which includes photos at 3 flap angles for AoA=5.98 deg
07/14/2021 - Added statement about standoff not contributing to the balance data (also mentioned elsewhere on website)
04/23/2021 - Link to existing BL tripping information on Geometries page added
04/21/2021 - The X and Z locations of points 40, 41, and 42 in wing row G were corrected in the surface pressure data files
04/01/2021 - Added information regarding how the tunnel polar was attained
03/17/2021 - Replaced R266RakeData.xlsx with R266RakeData_v2.xlsx, and provided formula
03/04/2021 - Added some related AIAA paper references
02/12/2021 - Floor rake data posted
01/13/2021 - Model surface pressures posted

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Responsible NASA Official: Christopher Rumsey
Page Curator: Christopher Rumsey
Last Updated: 09/09/2021