Wavevector Structure of Turbulent Wall Pressure and its Filtering by Normal Transmission and Spatial Averaging in Sensor Arrays

1985 ◽  
pp. 145-153
Author(s):  
David M. Chase
Keyword(s):  
Sensor Arrays ◽  
Wall Pressure ◽  
Spatial Averaging ◽  
Normal Transmission ◽  
Turbulent Wall

Spectral and Temporal Characteristics of Post-Stenotic Turbulent Wall Pressure Fluctuations

1979 ◽  
Vol 101 (2) ◽  
pp. 89-95 ◽  
Author(s):  
W. H. Pitts ◽  
C. F. Dewey
Keyword(s):  
Steady Flow ◽  
Pressure Fluctuations ◽  
Wall Pressure ◽  
Experimental Uncertainty ◽  
Flow Parameters ◽  
Wall Pressure Fluctuations ◽  
Power Spectral ◽  
Fluctuation Amplitude ◽  
Arterial Constriction ◽  
Turbulent Wall

The power spectral density of turbulent wall pressure fluctuations was measured in a tube downstream of a model arterial constriction. The flow parameters were varied from steady flow to conditions simulating human arterial pulsatile flow. Within the experimental uncertainty (±10 percent in characteristic turbulent frequency, fo, and ±25 percent in absolute rms pressure fluctuation amplitude), turbulent flow at the peak of systole produces wall pressure fluctuations identical to those of a steady flow at the same Reynolds number.

Effects of Convection and Decay of Turbulence on the Wall Pressure Wavenumber-Frequency Spectrum

1997 ◽  
Vol 119 (1) ◽  
pp. 50-55 ◽  
Author(s):  
W. L. Keith ◽  
B. M. Abraham
Keyword(s):  
Frequency Spectrum ◽  
Cross Correlation ◽  
Spatial Separation ◽  
Decay Rates ◽  
Wall Pressure ◽  
Convection Velocity ◽  
Velocity Measurements ◽  
Turbulent Structures ◽  
Correlation Data ◽  
Turbulent Wall

Cross-spectral and cross-correlation data from experiments and numerical simulations have shown the turbulent wall pressure convection velocity to vary with the streamwise sensor spatial separation. This variation is due to the spatial decay rates of turbulent structures in the inner and outer regions of the boundary layer. Its effect is shown to have a significant impact on the distribution of energy in the wavenumber-frequency spectrum Φ (k1, ω). The standard Corcos model is known to over predict the wavenumber-frequency spectrum at low wavenumbers. This is shown to result from its constant convection velocity assumption. The spectral levels at sub convective and lower wavenumbers are shown to be directly influenced by the spatial variation in convection velocity. Convection velocity measurements from past investigations that cover the range 285 ≤ Rθ ≤ 29,000 are compared, and an outer variable scaling is shown to effectively collapse the data.

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