On the accurate prediction of the wall-normal velocity in compressible boundary-layer flow

1993 ◽  
Vol 16 (2) ◽  
pp. 133-152 ◽  
Author(s):  
C. David Pruett
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Flow ◽  
Accurate Prediction ◽  
Normal Velocity ◽  
Compressible Boundary Layer ◽  
Layer Flow

scholarly journals Turbulence statistics in smooth wall oscillatory boundary layer flow

2018 ◽  
Vol 849 ◽  
pp. 192-230 ◽  
Author(s):  
Dominic A. van der A ◽  
Pietro Scandura ◽  
Tom O’Donoghue
Keyword(s):  
Boundary Layer ◽  
Normal Distribution ◽  
Boundary Layer Flow ◽  
Vertical Gradient ◽  
Streamwise Velocity ◽  
Normal Velocity ◽  
Half Cycle ◽  
Velocity Fluctuations ◽  
Oscillatory Boundary Layer ◽  
Layer Flow

Turbulence characteristics of an asymmetric oscillatory boundary layer flow are analysed through two-component laser-Doppler measurements carried out in a large oscillatory flow tunnel and direct numerical simulation (DNS). Five different Reynolds numbers, $R_{\unicode[STIX]{x1D6FF}}$, in the range 846–2057 have been investigated experimentally, where $R_{\unicode[STIX]{x1D6FF}}=\tilde{u} _{0max}\unicode[STIX]{x1D6FF}/\unicode[STIX]{x1D708}$ with $\tilde{u} _{0max}$ the maximum oscillatory velocity in the irrotational region, $\unicode[STIX]{x1D6FF}$ the Stokes length and $\unicode[STIX]{x1D708}$ the fluid kinematic viscosity. DNS has been carried out for the lowest three $R_{\unicode[STIX]{x1D6FF}}$ equal to 846, 1155 and 1475. Both experimental and numerical results show that the flow statistics increase during accelerating phases of the flow and especially at times of transition to turbulent flow. Once turbulence is fully developed, the near-wall statistics remain almost constant until the late half-cycle, with values close to those reported for steady wall-bounded flows. The higher-order statistics reach large values within a normalized wall distance of approximately $y/\unicode[STIX]{x1D6FF}=0.2$ at phases corresponding to the onset of low-speed streak breaking, because of the intermittency of the velocity fluctuations at these times. In particular, the flatness of the streamwise velocity fluctuations reaches values of the order of ten, while the flatness of the wall-normal velocity fluctuations reaches values of several hundreds. Far from the wall, at locations where the vertical gradient of the streamwise velocity is zero, the skewness is approximately zero and the flatness is approximately equal to 3, representative of a normal distribution. At lower elevations the distribution of the fluctuations deviate substantially from a normal distribution, but are found to be well described by other standard theoretical probability distributions.

scholarly journals Viscous modes within the compressible boundary-layer flow due to a broad rotating cone

2016 ◽  
Vol 81 (5) ◽  
pp. 940-960 ◽  
Author(s):  
P. D. Towers ◽  
Z. Hussain ◽  
P. T. Griffiths ◽  
S. J. Garrett
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Flow ◽  
Compressible Boundary Layer ◽  
Rotating Cone ◽  
Layer Flow
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