Test Data AC1-01
Aero-acoustic cavity
Application Challenge 1-01 © copyright ERCOFTAC 2004
Overview of Tests
The experimental conditions are described in Media:TR-026-20.pdf. The full range of tests covers a variety of free-stream Mach numbers between 0.4 and 1.35, and for two cavity configurations, so-called shallow and deep. We concentrate here on a single one of these, namely M=0.85 deep cavity.
Unsteady pressure measurements were recorded by 10 Kulite transducers along the centreline of the rig (which did not coincide with the centreline of the cavity itself), at a sampling rate of 6000Hz. The position of each transducer is given in Table 1.
| Transducer Number | Distance X from leading edge of cavity (mm) |
|---|---|
| 1 | 25.4 |
| 2 | 76.2 |
| 3 | 127.0 |
| 4 | 177.8 |
| 5 | 228.6 |
| 6 | 279.4 |
| 7 | 330.2 |
| 8 | 381.0 |
| 9 | 431.8 |
| 10 | 482.6 |
Table 1. Kulite Transducer Positions
M219D085.dat for the 10 transducer locations are stored using a sampling frequency of 6000 per second, for a total duration of just over 3.4 seconds. The M219DRMS.dat at these locations are also presented.
There is no independent verification of the validity/accuracy of the experimental data.
Test Conditions
Measurements have been performed on a range of free-stream Mach number, (empty) cavity depths, with and without doors at 90o open (Media:TR-026-20.pdf reports on the latter only). If appropriate, during the duration of the QNET project, a matrix of alternative test conditions against which to benchmark CFD calculations will be provided.
The specific test case of interest is classed as a deep cavity (L/D = 5) without doors, with flow conditions as follows:
M = 0.85
Re = 6.84e6 (based on cavity length of 0.508m)
P0 = 99612.06 Pa
P = 62059.14 Pa
T0 = 305.06 K
Incidence = 0o
References
Media:TR-026-20.pdf Henshaw M.J de C., “M219 Cavity case in Verification and Validation Data for Computational Unsteady Aerodynamics”, RTO-TR-26, AC/323(AVT)TP/19, October 2000
© copyright ERCOFTAC 2004
Contributors: Fred Mendonca; Richard Allen - Computational Dynamics Ltd
Site Design and Implementation: Atkins and UniS
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