The state of the art in measurement and interpretation of dynamic wall pressure beneath a turbulent boundary layer is reviewed. The mean pressure increase for shear flow over an orifice in a wall is explained, using triple deck theory, to stem from streamline contraction resulting from removal of the no-slip boundary condition. The effect in viscous hole diameters is too small to suggest that the dynamic pressure increase reported by Bull and Thomas (1976) for flow over a 'pinhole' microphone stems from this mechanism. It appears that any failure of high frequency spectra to collapse when made non-dimensional on inner wall variables is more likely due to transducer proudness or to error in the measurement of mean wall shear stress. The Corcos model is shown to be inadequate to describe cross-spectrum measurements. Both amplitude and phase depend also on the ratio of transducer separation to displacement boundary layer thickness. (JES).

Measurements made on some of the characteristics of the turbulent pressure field at the wall of a cylindrical pipe yielded root-mean-square pressure levels, power spectra, longitudinal space-time correlations, and convection velocity over a limited range of Reynolds number. The root-mean-square pressure levels were proportional to the dynamic pressure and when nondimensionalized by use of the dynamic pressure were observed to be independent of the Reynolds number and approximately equal to 0.008 over the Reynolds number range examined. The measurements indicate the existence of an apparent downstrea c nvection of the pressure field at a rate which is approximately the mean discharge velocity of the pipe flow. The pressure field in addition to being convected was also dispersed. Estimates of the scale of the turbulence were obtained. A limited statistical analysis of the pressure time history indicates that the amplitude variation is Gaussian. (Author).

Accompanying DVD-ROM contains ... "all chapters of the Springer Handbook."--Page 3 of cover.

One cannot overemphasize the importance of studying fluids in motion or at rest for a variety of scientific and engineering endeavors. Fluid mechanics as an art reaches back into antiquity, but its rational formulation is a relatively recent undertaking. Much of the physics of a particular flow situation can be understood by conducting appropriate experiments. Flow visualization techniques offer a useful tool to establish an overall picture of a flow field and to delineate broadly its salient features before embarking on more detailed quantitative measurements. Among the single-point measurements that are particularly difficult are those in separated flows, non-Newtonian fluids, rotating flows, and nuclear aerosols. Pressure, shear stress, vorticity, and heat transfer coefficient are also difficult quantities to measure, particularly for time-dependent flows. These and other special situations are among the topics covered in this volume. Each article emphasizes the development of a particular measuring technique. The topics covered were chosen because of their importance to the field, recent appeal, and potential for future development. The articles are comprehensive and coverage is pedagogical with a bias towards recent developments.