DPW-8 Test Case 3: Experimental data

References

For more details on the data, see the original reference paper (https://doi.org/10.1007/s00348-020-03118-y):

Sugioka, Y., Nakakita, K., Koike, S., Nakajima, T., Nonomura, T., and Asai, K., "Characteristic unsteady pressure field on a civil aifcraft wing related to the onset of transonic buffet", Experiments in Fluids (2021) 62:20

Related papers:

Sugioka, Y., Koike, S., Nakakita, K., Numata, D., Nonomura, T., and Asai, K., "Experimental analysis of transonic buffet on a 3D swept wing using fast-response pressure-sensitive paint", Experiments in Fluids (2018) 59:108.
Ohmichi, Y., Sugioka, Y., and Nakakita, K., "Stable dynamic mode decomposition algorithm for noisy pressure-sensitive-paint measurement data", AIAA Journal (2022) 60(3) 1965-1970
Sugioka, Y., Numata, D., Asai, K., Koike, S., Nakakita, K., and Nakajima, T., "Polymer/ceramic pressure-sensitive paint with reduced roughness for unsteady measurement in transonic flow", AIAA Journal (2018) 56(6), 2145-2156.

Copyright (c) JAXA Yosuke SUGIOKA. All Rights Reserved.

Geometry

The data shown in this page are measured on the 2.16% NASA-CRM model using JAXA wind tunnel test.

Reference Area, S = 0.179014 m²

Reference Chord, c = 0.15131 m( = MAC)

Reference Span, b = 1.26927 m( = span)

Moment Reference (X,Y,Z) = (0.72741, 0.0, 0.097627) m

Information on trip dots

Inner wing: wing-body junction to Yehudi break (trailing-edge discontinuous bend); Mid/Outer wing: equally divided from Yehudi break to wing-tip.

NOTE: Given the differences in Reynolds number, the trip dot heights in Test Case 3 are different from those in Test Case 2.

Aerodynamic coefficients

NOTE 1: The values are corrected for JAXA wind tunnel test. Additional corrections have been done with respect to the original reference paper and some differences exist on the corrected angles of attack.

NOTE 2: The aerodynamic coefficients were measured either simultaneously with PSP measurements (indicated as “PSP” in the data file) or independently as standalone balance measurements (indicated as “BL” in the data file). Since the force measurements were conducted before the pre-heating of the wind tunnel and balance had been completed, the drag coefficients measured simultaneously with the PSP tests are not provided.

Buffet Intensity Coefficient

C_B is the buffet intensity coefficient and was measured using the wing-root strain gate signal S_STG as:

C_B = (S_STG(α))_rms / (S_STG0)_rms

where: (S_STG0)_rms is the wing-root straing gauge signal under the zero-lift conditoin at α=-0.8deg.

The buffet intensity coefficient can be used an indicator for buffet onset.

C_p sectional distributions (Average, RMS, PSD) from steady pressure and Kulite sensors

C_p data was measured on two spanwise sections (indicated in the figure above) by:

- C_p (time averaged) by steady pressure sensor (ESP)

- C_p-rms by unsteady pressure sensor (Kulite)

Example figures for α=4.71deg are given below:

NOTE 1: The full-span model has a left "steady" wing and a right "unsteady" wing. Both time-averaged Cp data by ESP and rms pressure fluctuations data by Kulite sensors are measured on the right "unsteady" wing.

NOTE 2: Please note the PSD peak around 9 kHz is due to wind tunnel noise.

NOTE 3: For the exact location of each Kulite sensor and corresponding numbering, please check the AoA*_Cp_ESP.csv files.

C_p distributions (Average, RMS, PSD) from unsteady Pressure Sensitive Paint (uPSP)

The uPSP data have been mapped on the CRM jig shape (rescaled with mean aerodynamic chord).

The .dat files can be read in Tecplot and contain (x, y, z) coordinates, uPSP time-averaged pressure coefficient, and uPSP RMS pressure.

Masks have been applied to regions where the measurements are not reliable (unsteady pressure sensor lines, markers, areas near the model edges).

Sectional C_p distributions close to the spanwise locations of the Kulite sensor lines have also been provided. However, the root-mean squre pressure coefficients measured by the uPSP show some differences due to the camera exposure time that introduces low-pass filtering effects.

Deformation data

While official deformation measurements for this campaign are still pending, we can provide a preliminary data point for CFD qualitative validation: the wing tip exhibits a vertical deflection of approximately 10-12 mm at an Angle of Attack of 4.7 deg.

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