Journal ArticleDOI
Expanded analogy between Boltzmann kinetic theory of fluids and turbulence
TLDR
In this article, the effects of turbulent fluctuations have a striking resemblance to those of microscale (thermal) fluctuations in laminar flows, even to higher order in the Knudsen number.Abstract:
We demonstrate that the effects of turbulent fluctuations have a striking resemblance to those of microscale (thermal) fluctuations in laminar flows, even to higher order in the Knudsen number. This suggests that there may be a good basis for understanding turbulence in terms of Boltzmann kinetic theory. If so, turbulence may be better described in terms of ‘mixing times’ rather than the more classical ‘mixing lengths’. Comparisons are made to Reynolds-stress turbulence models.read more
Citations
More filters
Journal ArticleDOI
Aeroacoustic study of an axial engine cooling module using lattice-Boltzmann simulations and the Ffowcs Williams and Hawkings' analogy
TL;DR: In this paper, an acoustic study of a typical automotive engine cooling fan module using Lattice-Boltzmann simulations is presented, which is based on the power spectral density of wall-pressure fluctuations filtered at specific frequencies and the use of the Fowcs Williams and Hawkings (FWH) analogy has allowed identification of the main contributors on the module to the farfield noise.
Journal ArticleDOI
Macroscopic description of arbitrary Knudsen number flow using Boltzmann-BGK kinetic theory
TL;DR: In this article, the Boltzmann-Bhatnagar-Gross-Krook (BGK) kinetic theory with constant relaxation time is analyzed for finite Knudsen number flow and scalar transport.
Proceedings ArticleDOI
Numerical Simulation of a High-Lift Configuration with Embedded Fluidic Actuators
TL;DR: In this paper, numerical simulations have been performed for a vertical tail configuration with a deflected rudder, where the suction surface of the main element of this configuration is embedded with an array of 32 fluidic actuators that produce oscillating sweeping jets.
Journal ArticleDOI
Jet-installation noise and near-field characteristics of jet-surface interaction
TL;DR: The link between jet-installation noise and the near-field flow features of the corresponding isolated jet is studied by means of lattice-Boltzmann numerical simulations as discussed by the authors.
Journal ArticleDOI
The third golden age of aeroacoustics
TL;DR: In this article , the authors present a review of computational aero-acoustics, the field that deals with the noise generated by fluid flows and its propagation in the medium, highlighting the latest findings in both free flows (jet noise) and wall-bounded flows (airfoil, airframe, and turbomachinery noise) in more and more complex environments.
References
More filters
Journal ArticleDOI
The numerical computation of turbulent flows
Brian Launder,D. B. Spalding +1 more
TL;DR: In this paper, the authors present a review of the applicability and applicability of numerical predictions of turbulent flow, and advocate that computational economy, range of applicability, and physical realism are best served by turbulence models in which the magnitudes of two turbulence quantities, the turbulence kinetic energy k and its dissipation rate ϵ, are calculated from transport equations solved simultaneously with those governing the mean flow behaviour.
Book
Turbulence modeling for CFD
TL;DR: In this paper, the authors proposed a compressible ecoulement for compressible ECCs, based on the disquette reference record created on 2005-11-18, modified on 2016-08-08.
Small amplitude processes in charged and neutral one-component systems
TL;DR: In this article, a kinetic theory approach to collision processes in ionized and neutral gases is presented, which is adequate for the unified treatment of the dynamic properties of gases over a continuous range of pressures from the Knudsen limit to the high pressure limit where the aerodynamic equations are valid.
Journal ArticleDOI
Development of turbulence models for shear flows by a double expansion technique
TL;DR: In this article, a two-equation model and Reynolds stress transport model are developed for turbulent shear flows and tested for homogeneous shear flow and flow over a backward facing step.
Journal ArticleDOI
The Mathematical Theory of Non-Uniform Gases
TL;DR: Chapman and Cowling as mentioned in this paper showed that the ultimate scope of the descendent of the kinetic theory of gases must be the whole field of the properties of matter in bulk, derived from the atomic constitution of matter and from properties of atoms and their interactions.