A digital filter based generation of inflow data for spatially developing direct numerical or large eddy simulations
10 Apr 2003-Journal of Computational Physics (JOURNAL OF COMPUTATIONAL PHYSICS)-Vol. 186, Iss: 2, pp 652-665
TL;DR: In this article, the authors present a new approach for generating artificial velocity data which reproduces first and second order one point statistics as well as a locally given autocorrelation function.
About: This article is published in Journal of Computational Physics.The article was published on 2003-04-10. It has received 1058 citations till now. The article focuses on the topics: Reynolds stress equation model & Inflow.
Citations
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01 Jan 2005
TL;DR: In this paper, a new method for generation of synthetic turbulence, suitable for complex geometries and unstructured meshes, is presented, based on the classical view of turbulence as a superposition of coherent structures.
Abstract: The generation of inflow data for spatially developing turbulent flows is one of the challenges that must be addressed prior to the application of LES to industrial flows and complex geometries. A new method of generation of synthetic turbulence, suitable for complex geometries and unstructured meshes, is presented herein. The method is based on the classical view of turbulence as a superposition of coherent structures. It is able to reproduce prescribed first and second order one point statistics, characteristic length and time scales, and the shape of coherent structures. The ability of the method to produce realistic inflow conditions in the test cases of a spatially decaying homogeneous isotropic turbulence and of a fully developed turbulent channel flow is presented. The method is systematically compared to other methods of generation of inflow conditions (precursor simulation, spectral methods and algebraic methods).
613 citations
Cites background or methods from "A digital filter based generation o..."
...It has been shown that the results of DNS or LES, particularly in the cases of a plane jet (Klein et al., 2003), a spatially developing boundary layer (Lund et al....
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...It has been shown that the results of DNS or LES, particularly in the cases of a plane jet (Klein et al., 2003), a spatially developing boundary layer (Lund et al., 1998) or a backward facing step (Jarrin et al., 2003) are very sensitive to inflow conditions....
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...A more efficient technique for arbitrary inlet meshes is to filter random data on the inlet mesh (Klein et al., 2003)....
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TL;DR: In this paper, a new method for generation of synthetic turbulence, suitable for complex geometries and unstructured meshes, is presented, based on the classical view of turbulence as a superposition of coherent structures.
508 citations
TL;DR: In this article, the level set-ghost fluid method is applied to the Rayleigh instability of a liquid jet and a 3D simulation of the primary break-up of a turbulent liquid jet is presented.
488 citations
Cites methods from "A digital filter based generation o..."
...Here, we use the method derived by Klein et al. (2003), which consists in generating correlated random velocities with a prescribed length scale....
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TL;DR: In this paper, a large-eddy simulation of the interaction between an impinging oblique shock and a Mach 2.3 turbulent boundary layer is presented, which does not introduce any energetic low frequencies into the domain, hence avoiding possible interference with the shock/boundary layer interaction system.
Abstract: The need for better understanding of the low-frequency unsteadiness observed in shock wave/turbulent boundary layer interactions has been driving research in this area for several decades. We present here a large-eddy simulation investigation of the interaction between an impinging oblique shock and a Mach 2.3 turbulent boundary layer. Contrary to past large-eddy simulation investigations on shock/turbulent boundary layer interactions, we have used an inflow technique which does not introduce any energetically significant low frequencies into the domain, hence avoiding possible interference with the shock/boundary layer interaction system. The large-eddy simulation has been run for much longer times than previous computational studies making a Fourier analysis of the low frequency possible. The broadband and energetic low-frequency component found in the interaction is in excellent agreement with the experimental findings. Furthermore, a linear stability analysis of the mean flow was performed and a stationary unstable global mode was found. The long-run large-eddy simulation data were analyzed and a phase change in the wall pressure fluctuations was related to the global-mode structure, leading to a possible driving mechanism for the observed low-frequency motions.
455 citations
Cites methods from "A digital filter based generation o..."
...’s [30] digital filter approach....
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...[30]....
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...’s [43] method does not attempt to match the proper statistical moments, other synthetic approaches like the digital-filter (DF) approach [30] are designed to match ad-hoc first and second order statistical moments and spectra....
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TL;DR: Stochastic simulation of the liquid jet depletion in the framework of fragmentation under scaling symmetry and primary atomization in terms of Reynolds-averaged Navier-Stokes (RANS) mixing with a strong variation of density are highlighted.
Abstract: This review concerns recent progress in primary atomization modeling. The numerical approaches based on direct simulation are described first. Although direct numerical simulation (DNS) offers the potential to study the physical processes during primary atomization in detail, thereby supplementing experimental diagnostics, it also introduces severe numerical challenges. We outline these challenges and the numerical methods to address them, highlighting some recent efforts in performing detailed simulation of the primary atomization process. The second part is devoted to phenomenological models of primary atomization. Because earlier conventional models of breakup are well reported in the available literature, we highlight only two recent developments: (a) stochastic simulation of the liquid jet depletion in the framework of fragmentation under scaling symmetry and (b) primary atomization in terms of Reynolds-averaged Navier-Stokes (RANS) mixing with a strong variation of density.
384 citations
References
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Book•
01 Jan 1953
TL;DR: In this article, the kinematics of the field of homogeneous turbulence and the universal equilibrium theory of decay of the energy-containing eddies are discussed. But the authors focus on the dynamics of decay and not on the probability distribution of u(x).
Abstract: Preface 1 Introduction 2 Mathematics representation of the field of turbulence 3 The kinematics of homogeneous turbulence 4 Some linear problems 5 General dynamics of decay 6 The universal equilibrium theory 7 Decay of the energy-containing eddies 8 The probability distribution of u(x) Bibliography of research on homogeneous turbulence Index
3,121 citations
TL;DR: In this paper, the authors consider the formation of droplet clouds or sprays that subsequently burn in combustion chambers, which is caused by interfacial instabilities, such as the Kelvin-Helmholtz instability.
Abstract: The numerical simulation of flows with interfaces and free-surface flows is a vast topic, with applications to domains as varied as environment, geophysics, engineering, and fundamental physics. In engineering, as well as in other disciplines, the study of liquid-gas interfaces is important in combustion problems with liquid and gas reagents. The formation of droplet clouds or sprays that subsequently burn in combustion chambers originates in interfacial instabilities, such as the Kelvin-Helmholtz instability. What can numerical simulations do to improve our understanding of these phenomena? The limitations of numerical techniques make it impossible to consider more than a few droplets or bubbles. They also force us to stay at low Reynolds or Weber numbers, which prevent us from finding a direct solution to the breakup problem. However, these methods are potentially important. First, the continuous improvement of computational power (or, what amounts to the same, the drop in megaflop price) continuously extends the range of affordable problems. Second, and more importantly, the phenomena we consider often happen on scales of space and time where experimental visualization is difficult or impossible. In such cases, numerical simulation may be a useful prod to the intuition of the physicist, the engineer, or the mathematician. A typical example of interfacial flow is the collision between two liquid droplets. Finding the flow involves the study not only of hydrodynamic fields in the air and water phases but also of the air-water interface. This latter part
1,949 citations
TL;DR: In this paper, the turbulent boundary layer on a flat plate, with zero pressure gradient, is simulated numerically at four stations between R sub theta = 225 and R sub tta = 1410.
Abstract: The turbulent boundary layer on a flat plate, with zero pressure gradient, is simulated numerically at four stations between R sub theta = 225 and R sub theta = 1410. The three-dimensional time-dependent Navier-Stokes equations are solved using a spectra method with up to about 10 to the 7th power grid points. Periodic spanwise and stream-wise conditions are applied, and a multiple-scale procedure is applied to approximate the slow streamwise growth of the boundary layer. The flow is studied, primarily, from a statistical point of view. The solutions are compared with experimental results. The scaling of the mean and turbulent quantities with Reynolds number is examined and compared with accepted laws, and the significant deviations are documented. The turbulence at the highest Reynolds number is studied in detail. The spectra are compared with various theoretical models. Reynolds-stress budget data are provided for turbulence-model testing.
1,934 citations
TL;DR: In this article, direct numerical simulation (DNS) of turbulent flows has been reviewed and the complementary nature of experiments and computations in turbulence research has been illustrated, as well as how DNS has impacted turbulence modeling and provided further insight into the structure of turbulent boundary layers.
Abstract: ▪ Abstract We review the direct numerical simulation (DNS) of turbulent flows. We stress that DNS is a research tool, and not a brute-force solution to the Navier-Stokes equations for engineering problems. The wide range of scales in turbulent flows requires that care be taken in their numerical solution. We discuss related numerical issues such as boundary conditions and spatial and temporal discretization. Significant insight into turbulence physics has been gained from DNS of certain idealized flows that cannot be easily attained in the laboratory. We discuss some examples. Further, we illustrate the complementary nature of experiments and computations in turbulence research. Examples are provided where DNS data has been used to evaluate measurement accuracy. Finally, we consider how DNS has impacted turbulence modeling and provided further insight into the structure of turbulent boundary layers.
1,572 citations