Wall pressure fluctuations due to boundary‐layer transition

2000 ◽  
Vol 108 (5) ◽  
pp. 2451-2451
Author(s):  
Gerald C. Lauchle ◽  
Sewon Park
Keyword(s):  
Boundary Layer ◽  
Pressure Fluctuations ◽  
Wall Pressure ◽  
Boundary Layer Transition ◽  
Layer Transition ◽  
Wall Pressure Fluctuations

Modeling the Wavevector-Frequency Spectrum of Boundary-Layer Wall Pressure During Transition on a Flat Plate

1990 ◽  
Vol 112 (4) ◽  
pp. 523-534 ◽  
Author(s):  
M. A. Josserand ◽  
G. C. Lauchle
Keyword(s):  
Boundary Layer ◽  
Frequency Spectrum ◽  
Pressure Fluctuations ◽  
Basic Result ◽  
Space Time ◽  
Wall Pressure ◽  
Boundary Layer Transition ◽  
Layer Transition ◽  
Turbulent Layer ◽  
Wall Pressure Fluctuations

A spectral model for the wall-pressure fluctuations induced on a zero pressure gradient, flat, rigid surface by a transitioning boundary layer at low Mach number is developed in this paper. The central assumption used in this modeling is that the space-time statistics associated with the formation, convection, and interaction of turbulent spots in a naturally occurring boundary-layer transition are independent of the space-time statistics of the wall-pressure fluctuations that are induced by the turbulence in the individual spots. Space-time correlations for the spots were determined experimentally and semi-empirical formulae are developed to predict these correlations. Previously published statistical descriptions of turbulence-induced wall-pressure fluctuations are coupled with the spot statistics to arrive at the model for the wavevector-frequency spectrum of the transition region. The basic result suggests that the wall-pressure wavevector-frequency spectrum of a transitioning boundary layer is approximately that produced by a fully-turbulent layer weighted by the intermittency factor.

Predicting Turbulent Boundary Layer Wall Pressure Fluctuations in Adverse Pressure Gradients

2005 ◽  
Author(s):  
Frank J. Aldrich
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Pressure Gradient ◽  
Pressure Fluctuations ◽  
Adverse Pressure Gradient ◽  
Wall Pressure ◽  
Prediction Tool ◽  
Pressure Gradients ◽  
Wall Pressure Fluctuations ◽  
The Difference

A physics-based approach is employed and a new prediction tool is developed to predict the wavevector-frequency spectrum of the turbulent boundary layer wall pressure fluctuations for subsonic airfoils under the influence of adverse pressure gradients. The prediction tool uses an explicit relationship developed by D. M. Chase, which is based on a fit to zero pressure gradient data. The tool takes into account the boundary layer edge velocity distribution and geometry of the airfoil, including the blade chord and thickness. Comparison to experimental adverse pressure gradient data shows a need for an update to the modeling constants of the Chase model. To optimize the correlation between the predicted turbulent boundary layer wall pressure spectrum and the experimental data, an optimization code (iSIGHT) is employed. This optimization module is used to minimize the absolute value of the difference (in dB) between the predicted values and those measured across the analysis frequency range. An optimized set of modeling constants is derived that provides reasonable agreement with the measurements.

The scaling of the wall pressure fluctuations in polymer-modified turbulent boundary layer flow

2000 ◽  
Vol 108 (1) ◽  
pp. 71-75 ◽  
Author(s):  
Timothy A. Brungart ◽  
Wayne J. Holmberg ◽  
Arnold A. Fontaine ◽  
Steven Deutsch ◽  
Howard L. Petrie
Keyword(s):  
Boundary Layer ◽  
Turbulent Boundary Layer ◽  
Boundary Layer Flow ◽  
Pressure Fluctuations ◽  
Wall Pressure ◽  
Wall Pressure Fluctuations ◽  
Turbulent Boundary Layer Flow ◽  
Layer Flow
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