Summary of Anticipated/Emerging Dataset

30P30N 3-Element, Simplified (Zero Sweep, Zero Taper) High-Lift Configuration (Modified Slat)

With Focus on Slat Cove Noise

Submitted by

Meelan Choudhari, Mehdi Khorrami, and Dan Neuhart

NASA Langley Research Center

1.  Experimental configuration

2D, unswept 30P30N 3-element high lift configuration at one or more angles of attack relevant to aircraft approach

2.  Flow Conditions (range of flow parameters)

(e.g., 18 inch stowed chord, M » 0.17, AOA = 4-6 deg, Re = 1.7 million)

3.  Scope of measurements (in general terms)

  1. Force and moment coefficients: not expected at this point
  2. Static surface pressure: chordwise variation at 3 spanwise stations
  3. Dynamic surface pressure: select chordwise locations and a spanwise array near trailing edge (locations based on previous computations)
  4. Time resolved off-surface (flow) data: none expected due to sensitivity of separated flow region to hot wire measurements
  5. Global flow visualization/measurements: PIV data
  6. Other off-surface data (LDV, etc.): None expected at this point
  7. Acoustic data: Expected, but timeframe uncertain

4.  Special/unique features of dataset (The Good…)

§  Simple yet realistic configuration for slat noise

§  Expect multi-facility measurements

§  Model has slightly thicker slat trailing edge than the unmodified 30P30N configuration, which has been the topic of a previous steady, 2D CFD Challenge effort (Klausmeyer and Lin, NASA-TM-112858, May 1997) that also produced hot wire measurements of boundary layer profiles and limited PIV of slat wake at higher Reynolds numbers), as well as yielding a rich dataset of near-field measurements relevant to airframe noise application.

§  Anticipated data will establish consistency with previous measurements for nearly similar model

§  Unlike BANC-I configurations, dynamic transducer placement has been optimized on the basis of 3D, near-field CFD.

  1. Notable shortcomings of dataset

The Bad….

§  Realism: no sweep

§  Large span, tunnel wall installation effects

§  Near-field flow physics: low Reynolds number, separation along flap suction surface

§  Near-field flow detail: No measurements of state of the boundary layer (as

yet)

And the Ugly….

§  Timeframe: Multi-facility fluid dynamic and acoustic measurements involving the same model (as well as different models) tested by several international partners are expected within the near future, but only data available at present corresponds to near-field measurements reported in AIAA 2004-2801.

In short, yet another imperfect benchmark that can be made “less imperfect”…

  1. Data to be made available (including approximate size in megabytes if exceeding 1MB)
  2. Geometry (tabular data of airfoil coordinates, IGES file) for design model + comparison with as built QA data
  3. Mean flow measurements: chordwise static pressure variation at 3 spanwise locations, PIV measurements within the slat cove and trailing edge wake regions
  4. Dynamic surface pressure: narrowband frequency spectra at all dynamic pressure transducer locations, together with p’ time history if necessary, spanwise correlation function, limited data for spanwise coherence at specific frequencies
  5. Off-surface unsteady flow: No hot wire or LDV measurements expected within slat cove region
  6. Global data/flow vis. (Likely PIV measurements of slat cove and trailing edge wake regions)
  7. Acoustic data (acoustic intensity and spectra at selected locations within symmetry plane)
  8. Error and uncertainty analysis (partially addressed in AIAA 2004-2801)
  9. Significant omissions from publicly disseminated data: None anticipated

7.  Intended mode of dataset dissemination (indicate order of preference)

  1. Available upon request on a case by case basis ______
  2. Data hosted by original team and linked via AIAA website ______
  3. Dataset transferred to AIAA for hosting and public dissemination ______
  4. Some other mode (e.g., a mix of a. and b.) _b and/or c______
  1. Relevant publications, including annotations if necessary

A rich legacy of previously documented measurements (Jenkins et al., AIAA Paper 2004-2801) for unmodified 30P30N configuration, in the form of static pressures, planar PIV within the cove near slat trailing edge, (and unanalyzed stereo PIV measurements of spanwise structure near the shear layer reattachment location). Above near-field measurements have been used in comparisons with various near field computations, both in house at NASA and by other partners. (References to be added in the course of problem statement formulation for BANC-II workshop.)

9.  Special remarks (if any)

Instrumented slat model in final stages of fabrication. Measurement strategy will be analogous to the tandem cylinder experiment, involving more than one facility. Options for acoustic measurements are being evaluated at this time.

Measurements at other flow conditions feasible if a broad enough interest exists.

Will entertain requests for additional details of surface p’ and acoustic data such as near-field to far-field correlation, etc.)

Other international partners will be involved in both fluid dynamic and aeroacoustic measurements on the same model.

Slightly larger version of original 30P30N geometry (i.e., Jenkins et al./BART version) to be tested in Brazil (Silent Aircraft Initiative).

10. Desired collaborations:

Experiments:

1.  Acoustic measurements

2.  Complementary measurements within the slat cove region (LDV, time accurate PSP, etc.)

Computations and Modeling:

Envisioned path includes complementary computations of open jet tunnel installation, plus a collaborative, team based approach that could extend beyond comparison with measurements, including simultaneous advancement of benchmark quality and more precise understanding of noise source and propagation mechanisms. (Not just participants or contributors, but owners/shareholders!) Opportunities for role players with a specific niche in computations and/or measurements also exist and suggestions/offers from other community members are welcome.