Dynamic Wall Pressure Measurements
Abstract
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 01, 1988
- Accession Number
- ADA203551
Entities
People
- Patrick Leehey
Organizations
- Massachusetts Institute of Technology