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

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Contributors: Fred Mendonca; Richard Allen - Computational Dynamics Ltd

Site Design and Implementation: Atkins and UniS

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