### ASA 126th Meeting Denver 1993 October 4-8

## 5aNS8. Computation of turbulent boundary layer wall pressure spectra.

**Dean Capone
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*Naval Surface Warfare Ctr., Acoust. Res. Detachment, Code 752, Bayview, ID
83803
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**Gerald C. Lauchle
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*Penn State Univ., State College, PA 16804
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The suitability of various wave-vector--frequency spectral models for
predicting the point wall pressure spectrum due to developed turbulent
boundary-layer flow over planar, rigid surfaces is investigated. The
incompressible and compressible models developed previously [D. Chase, J. Sound
Vib. 112, 125--147 (1987)] are given particular attention. The effect of
finite-sized measurement transducers is included in the integration of the
theoretical wave-vector--frequency spectrum over the in-plane wave numbers in
order to arrive at an attenuated point pressure frequency spectrum that can be
compared directly to existing experimental data [G. Schewe, J. Fluid Mech. 134,
311--328 (1983) (air), G. C. Lauchle and M. A. Daniels, Phys. Fluids 30,
3019--3024 (1987) (glycerine), and M. P. Horne and R. A. Handler, Exp. Fluids
12, 136--139 (1991) (water)]. The selected experiments cover a wide range of
fluid properties and Reynolds numbers: it is found that the optimum set of
empirical constants needed to exercise the Chase models depends on the
experiment considered. The need to consider viscous effects in future modeling
is borne out when dealing with viscous fluids like glycerine. [Work supported
by various U.S. Navy projects at NSWC and ARL Penn State.]