Statistics and structures of pressure in isotropic turbulence
- 1 August 1999
- journal article
- Published by AIP Publishing in Physics of Fluids
- Vol. 11 (8), 2235-2250
- https://doi.org/10.1063/1.870085
Abstract
Statistics and structures of pressure in three-dimensional incompressible isotropic turbulence are studied using high-resolution direct numerical simulation for Taylor microscale Reynolds numbers up to 220. It is found that the probability distribution function (PDF) of pressure has negative skewness due to both kinematic and dynamic effects, in contrast to the statistics of the pressure head, whose PDF is almost symmetric. The statistical relations among pressure, vorticity, dissipation and kinetic energy are investigated using conditional averaging. The averaged pressure, conditional on the local enstrophy, shows a linear dependence on enstrophy in the high-enstrophy region. Structure relations between pressure and other physical quantities are qualitatively examined using three-dimensional visualization of iso-surfaces. It is found that the high-vorticity regions are strongly correlated with the low-pressure regions. However, it appears that experimental visualization techniques for detecting high-intensity vortices using microbubbles in low-pressure regions might only be valid for those very-high-vorticity regions where the local enstrophy is at least five times higher than the root mean square enstrophy. The scaling law of the pressure structure function is also presented for both conventional and extended self-similarity. It is found that the pressure increment, delta(r)p, scales with the velocity increment, delta(r)u, for the Reynolds numbers studied: delta(r)p similar to delta(r)u. For flows at moderate Reynolds numbers, it is demonstrated that the extended self-similarity gives better pressure scalings than results from traditional similarity solutions. (C) 1999 American Institute of Physics. [S1070-6631(99)00108-7].Keywords
This publication has 30 references indexed in Scilit:
- A numerical study of pressure fluctuations in three-dimensional, incompressible, homogeneous, isotropic turbulencePhysics of Fluids, 1994
- Skewed, exponential pressure distributions from Gaussian velocitiesPhysics of Fluids A: Fluid Dynamics, 1993
- Pressure fluctuations in swirling turbulent flowsJournal de Physique II, 1993
- Spectral large-eddy simulation of isotropic and stably stratified turbulenceJournal of Fluid Mechanics, 1992
- Pressure Field within Homogeneous Anisotropic TurbulenceThe Journal of the Acoustical Society of America, 1956
- Quadruple Velocity Correlations and Pressure Fluctuations in Isotropic TurbulenceJournal of the Aeronautical Sciences, 1953
- Pressure fluctuations in isotropic turbulenceMathematical Proceedings of the Cambridge Philosophical Society, 1951
- Zur statistischen Theorie der TurbulenzThe European Physical Journal A, 1948
- Statistical theory of turbulence V-Effect of turbulence on boundary layer theoretical discussion of relationship between scale of turbulence and critical resistance of spheresProceedings of the Royal Society of London. Series A - Mathematical and Physical Sciences, 1936
- Statistical theory of turbulence IV-Diffusion in a turbulent air streamProceedings of the Royal Society of London. Series A - Mathematical and Physical Sciences, 1935