Log in

Relevant bibliographies by topics / DNS simulation / Journal articles

To see the other types of publications on this topic, follow the link: DNS simulation.

Journal articles on the topic 'DNS simulation'

Author: Grafiati

Published: 4 June 2021

Last updated: 4 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'DNS simulation.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Michelassi, V., J. G. Wissink, and W. Rodi. "Direct numerical simulation, large eddy simulation and unsteady Reynolds-averaged Navier—Stokes simulations of periodic unsteady flow in a low-pressure turbine cascade: A comparison." Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 217, no. 4 (2003): 403–11. http://dx.doi.org/10.1243/095765003322315469.

Full text

Abstract:

The unsteady periodic flow in a low-pressure (LP) prismatic turbine vane with incoming wakes is computed by direct numerical simulation (DNS), large eddy simulation (LES) and unsteady Reynolds-averaged Navier—Stokes simulations (URANSs). The results are compared with existing measurements at a Reynolds number Re = 5.18 × 104 which reveal the presence of a large unsteady stalled region on the suction side. Both DNS and LES suggest that the boundary layer separates while being still laminar, with subsequent turbulent reattachment. Several URANSs with and without a transition model and a constrai

APA, Harvard, Vancouver, ISO, and other styles

2

Hami, Khelifa. "Turbulence Modeling a Review for Different Used Methods." International Journal of Heat and Technology 39, no. 1 (2021): 227–34. http://dx.doi.org/10.18280/ijht.390125.

Full text

Abstract:

This contribution represents a critical view of the advantages and limits of the set of mathematical models of the physical phenomena of turbulence. Turbulence models can be grouped into two categories, depending on how turbulent quantities are calculated: direct numerical simulations (DNS) and RANS (Reynolds Averaged Navier-Stokes Equations) models. The disadvantage of these models is that they require enormous computing power, inaccessible, especially for large and complicated geometries. For this reason, hybrid models (combinations between DNS and RANS methods) have been developed, for exam

APA, Harvard, Vancouver, ISO, and other styles

3

Thomas, Lois, Wojciech W. Grabowski, and Bipin Kumar. "Diffusional growth of cloud droplets in homogeneous isotropic turbulence: DNS, scaled-up DNS, and stochastic model." Atmospheric Chemistry and Physics 20, no. 14 (2020): 9087–100. http://dx.doi.org/10.5194/acp-20-9087-2020.

Full text

Abstract:

Abstract. This paper presents a novel methodology to use direct numerical simulation (DNS) to study the impact of isotropic homogeneous turbulence on the condensational growth of cloud droplets. As shown by previous DNS studies, the impact of turbulence increases with the computational domain size, that is, with the Reynolds number, because larger eddies generate higher and longer-lasting supersaturation fluctuations that affect growth of individual cloud droplets. The traditional DNS can only simulate a limited range of scales because of the excessive computational cost that comes from resolv

APA, Harvard, Vancouver, ISO, and other styles

4

Kimmel-Klotzkin, Shari J., and Fadi P. Deek. "Large Eddy Simulation of Rotating Finite Source Convection." Journal of Applied Mechanics 73, no. 1 (2005): 79–87. http://dx.doi.org/10.1115/1.1991859.

Full text

Abstract:

Numerical simulations of turbulent convection under the influence of rotation will help understand mixing in oceanic flows. Though direct numerical simulations (DNS) can accurately model rotating convective flows, this method is limited to small scale and low speed flows. A large eddy simulation (LES) with the Smagorinsky subgrid scale model is used to compute the time evolution of a rotating convection flow generated by a buoyancy source of finite size at a relatively high Rayleigh number. Large eddy simulations with eddy viscosity models have been used successfully for other rotating convect

APA, Harvard, Vancouver, ISO, and other styles

5

Lu, Tianshi, Roman Samulyak, and James Glimm. "Direct Numerical Simulation of Bubbly Flows and Application to Cavitation Mitigation." Journal of Fluids Engineering 129, no. 5 (2006): 595–604. http://dx.doi.org/10.1115/1.2720477.

Full text

Abstract:

The direct numerical simulation (DNS) method has been used to the study of the linear and shock wave propagation in bubbly fluids and the estimation of the efficiency of the cavitation mitigation in the container of the Spallation Neutron Source liquid mercury target. The DNS method for bubbly flows is based on the front tracking technique developed for free surface flows. Our front tracking hydrodynamic simulation code FronTier is capable of tracking and resolving topological changes of a large number of interfaces in two- and three-dimensional spaces. Both the bubbles and the fluid are compr

APA, Harvard, Vancouver, ISO, and other styles

6

Wang, Xian, Yanqin Shangguan, Naoyuki Onodera, Hiromichi Kobayashi, and Takayuki Aoki. "Direct Numerical Simulation and Large Eddy Simulation on a Turbulent Wall-Bounded Flow Using Lattice Boltzmann Method and Multiple GPUs." Mathematical Problems in Engineering 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/742432.

Full text

Abstract:

Direct numerical simulation (DNS) and large eddy simulation (LES) were performed on the wall-bounded flow atReτ=180using lattice Boltzmann method (LBM) and multiple GPUs (Graphic Processing Units). In the DNS, 8 K20M GPUs were adopted. The maximum number of meshes is6.7×107, which results in the nondimensional mesh size ofΔ+=1.41for the whole solution domain. It took 24 hours for GPU-LBM solver to simulate3×106LBM steps. The aspect ratio of resolution domain was tested to obtain accurate results for DNS. As a result, both the mean velocity and turbulent variables, such as Reynolds stress and v

APA, Harvard, Vancouver, ISO, and other styles

7

CHUNG, D., and D. I. PULLIN. "Direct numerical simulation and large-eddy simulation of stationary buoyancy-driven turbulence." Journal of Fluid Mechanics 643 (December 24, 2009): 279–308. http://dx.doi.org/10.1017/s0022112009992801.

Full text

Abstract:

We report direct numerical simulation (DNS) and large-eddy simulation (LES) of statistically stationary buoyancy-driven turbulent mixing of an active scalar. We use an adaptation of the fringe-region technique, which continually supplies the flow with unmixed fluids at two opposite faces of a triply periodic domain in the presence of gravity, effectively maintaining an unstably stratified, but statistically stationary flow. We also develop a new method to solve the governing equations, based on the Helmholtz–Hodge decomposition, that guarantees discrete mass conservation regardless of iteratio

APA, Harvard, Vancouver, ISO, and other styles

8

Viti, Nicolò, Daniel Valero, and Carlo Gualtieri. "Numerical Simulation of Hydraulic Jumps. Part 2: Recent Results and Future Outlook." Water 11, no. 1 (2018): 28. http://dx.doi.org/10.3390/w11010028.

Full text

Abstract:

During the past two decades, hydraulic jumps have been investigated using Computational Fluid Dynamics (CFD). The second part of this two-part study is devoted to the state-of-the-art of the numerical simulation of the hydraulic jump. First, the most widely-used CFD approaches, namely the Reynolds-Averaged Navier–Stokes (RANS), the Large Eddy Simulation (LES), the Direct Numerical Simulation (DNS), the hybrid RANS-LES method Detached Eddy Simulation (DES), as well as the Smoothed Particle Hydrodynamics (SPH), are introduced pointing out their main characteristics also in the context of the bes

APA, Harvard, Vancouver, ISO, and other styles

9

Zhu, Haitao, Feng Wu, Quanyong Xu, and Peng Shan. "Direct Numerical Simulation of Turbine Cascade Flow with Heat Transfer." International Journal of Turbo & Jet-Engines 36, no. 4 (2019): 445–56. http://dx.doi.org/10.1515/tjj-2016-0082.

Full text

Abstract:

Abstract Two- and three-dimensional direct numerical simulation (DNS) of turbine cascade flow at low Reynolds number with heat transfer are performed using high-order finite difference method. Two-dimensional laminar computation which is used to construct the initial flow of three-dimensional DNS fails to predict Stanton number on the second half of suction side where the flow is turbulent in experiment. In three-dimensional DNS, transition is triggered by periodic blow-and-suction disturbances. Numerical experiments show that phase randomness of the disturbance is not necessary to trigger the

APA, Harvard, Vancouver, ISO, and other styles

10

Boguslawski, Andrzej, Artur Tyliszczak, Agnieszka Wawrzak, and Karol Wawrzak. "Numerical simulation of free jets." International Journal of Numerical Methods for Heat & Fluid Flow 27, no. 5 (2017): 1056–63. http://dx.doi.org/10.1108/hff-03-2016-0103.

Full text

Abstract:

Purpose The purpose of the paper is to summarize recent achievements and suggest further research directions in numerical studies of round free jets with particular attention on the influence of the inlet parameters (mean velocity, turbulence intensity, length and time scales) on the jet dynamics. Design/methodology/approach The large eddy simulation (LES) and direct numerical simulation (DNS) are regarded as accurate tools which can support expensive and requiring sophisticated measurements techniques experimental studies. In the paper, the authors present challenges and recent findings relat

APA, Harvard, Vancouver, ISO, and other styles

11

Cao, Hui, Xiaodong Jia, Yongliang Li, Carlos Amador, and Yulong Ding. "CFD-DNS simulation of irregular-shaped particle dissolution." Particuology 50 (June 2020): 144–55. http://dx.doi.org/10.1016/j.partic.2019.08.003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

Wang, Guoqing, Partha P. Mukherjee, and Chao-Yang Wang. "Direct numerical simulation (DNS) modeling of PEFC electrodes." Electrochimica Acta 51, no. 15 (2006): 3139–50. http://dx.doi.org/10.1016/j.electacta.2005.09.002.

Full text

APA, Harvard, Vancouver, ISO, and other styles

13

Wang, Guoqing, Partha P. Mukherjee, and Chao-Yang Wang. "Direct numerical simulation (DNS) modeling of PEFC electrodes." Electrochimica Acta 51, no. 15 (2006): 3151–60. http://dx.doi.org/10.1016/j.electacta.2005.09.003.

Full text

APA, Harvard, Vancouver, ISO, and other styles

14

Waggy, Scott B., Sedat Biringen, and Peter P. Sullivan. "Direct numerical simulation of top-down and bottom-up diffusion in the convective boundary layer." Journal of Fluid Mechanics 724 (April 30, 2013): 581–606. http://dx.doi.org/10.1017/jfm.2013.130.

Full text

Abstract:

AbstractA direct numerical simulation (DNS) of an unstably stratified convective boundary layer with system rotation was performed to study top-down and bottom-up diffusion processes. In order to better understand near-wall dynamics associated with scalar diffusion in the absence of surface roughness, direct simulation is utilized to numerically integrate the governing equations that model the atmospheric boundary layer. The ratio of the inversion height to Obukhov length scale, ${z}_{i} / L= - 49. 1$, indicates moderately strong heating for the case studied. Two passive scalars were initializ

APA, Harvard, Vancouver, ISO, and other styles

15

Ghassemzadeh, Shahdad, Maria Gonzalez Perdomo, Manouchehr Haghighi, and Ehsan Abbasnejad. "Deep net simulator (DNS): a new insight into reservoir simulation." APPEA Journal 60, no. 1 (2020): 124. http://dx.doi.org/10.1071/aj19093.

Full text

Abstract:

Reservoir simulation plays a vital role as a diagnostics tool to better understand and predict a reservoir’s behaviour. The primary purpose of running a reservoir simulation is to replicate reservoir performance under different production conditions; therefore, the development of a reliable and fast dynamic reservoir model is a priority for the industry. In each simulation, the reservoir is divided into millions of cells, with fluid and rock attributes assigned to each cell. Based on these attributes, flow equations are solved through numerical methods, resulting in an excessively long process

APA, Harvard, Vancouver, ISO, and other styles

16

SCHLATTER, PHILIPP, and RAMIS ÖRLÜ. "Assessment of direct numerical simulation data of turbulent boundary layers." Journal of Fluid Mechanics 659 (July 16, 2010): 116–26. http://dx.doi.org/10.1017/s0022112010003113.

Full text

Abstract:

Statistics obtained from seven different direct numerical simulations (DNSs) pertaining to a canonical turbulent boundary layer (TBL) under zero pressure gradient are compiled and compared. The considered data sets include a recent DNS of a TBL with the extended range of Reynolds numbers Reθ = 500–4300. Although all the simulations relate to the same physical flow case, the approaches differ in the applied numerical method, grid resolution and distribution, inflow generation method, boundary conditions and box dimensions. The resulting comparison shows surprisingly large differences not only i

APA, Harvard, Vancouver, ISO, and other styles

17

Uchiyama, T. "Accuracy of large eddy simulation for turbulent flow by the finite element method." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 212, no. 7 (1998): 643–50. http://dx.doi.org/10.1243/0954406981521600.

Full text

Abstract:

This paper investigates the computational accuracy and CPU (central processing unit) time of large eddy simulation (LES) for turbulent flows performed by the finite element method. The investigations are accomplished by simulating a fully developed turbulent channel flow, which was analysed by Kim et al. using the direct numerical simulation (DNS) technique. When the advection term is discretized in gradient form, the turbulence decays and disappears with the passage of time. In using a multipass algorithm to solve the velocity field, the numerical result obtained by discretizing the advection

APA, Harvard, Vancouver, ISO, and other styles

18

Huang, P. G., G. N. Coleman, and P. Bradshaw. "Compressible turbulent channel flows: DNS results and modelling." Journal of Fluid Mechanics 305 (December 25, 1995): 185–218. http://dx.doi.org/10.1017/s0022112095004599.

Full text

Abstract:

The present paper addresses some topical issues in modelling compressible turbulent shear flows. The work is based on direct numerical simulation (DNS) of two supersonic fully developed channel flows between very cold isothermal walls. Detailed decomposition and analysis of terms appearing in the mean momentum and energy equations are presented. The simulation results are used to provide insights into differences between conventional Reynolds and Favre averaging of the mean-flow and turbulent quantities. Study of the turbulence energy budget for the two cases shows that compressibility effects

APA, Harvard, Vancouver, ISO, and other styles

19

CHIKATAMARLA, S. S., C. E. FROUZAKIS, I. V. KARLIN, A. G. TOMBOULIDES, and K. B. BOULOUCHOS. "Lattice Boltzmann method for direct numerical simulation of turbulent flows." Journal of Fluid Mechanics 656 (July 8, 2010): 298–308. http://dx.doi.org/10.1017/s0022112010002740.

Full text

Abstract:

We present three-dimensional direct numerical simulations (DNS) of the Kida vortex flow, a prototypical turbulent flow, using a novel high-order lattice Boltzmann (LB) model. Extensive comparisons of various global and local statistical quantities obtained with an incompressible-flow spectral element solver are reported. It is demonstrated that the LB method is a promising alternative for DNS as it quantitatively captures all the computed statistics of fluid turbulence.

APA, Harvard, Vancouver, ISO, and other styles

20

WISSINK, JAN G., and WOLFGANG RODI. "Direct numerical simulation of heat transfer from the stagnation region of a heated cylinder affected by an impinging wake." Journal of Fluid Mechanics 669 (January 14, 2011): 64–89. http://dx.doi.org/10.1017/s0022112010004866.

Full text

Abstract:

The effect of an incoming wake on the flow around and heat transfer from the stagnation region of a circular cylinder was studied using direct numerical simulations (DNSs). Four simulations were carried out at a Reynolds number (based on free-stream velocity and cylinder diameterD) ofReD= 13200: one two-dimensional (baseline) simulation and three three-dimensional simulations. The three-dimensional simulations comprised a baseline simulation with a uniform incoming velocity field, a simulation in which realistic wake data – generated in a separate precursor DNS – were introduced at the inflow

APA, Harvard, Vancouver, ISO, and other styles

21

Wood, Brian D., Xiaoliang He, and Sourabh V. Apte. "Modeling Turbulent Flows in Porous Media." Annual Review of Fluid Mechanics 52, no. 1 (2020): 171–203. http://dx.doi.org/10.1146/annurev-fluid-010719-060317.

Full text

Abstract:

Turbulent flows in porous media occur in a wide variety of applications, from catalysis in packed beds to heat exchange in nuclear reactor vessels. In this review, we summarize the current state of the literature on methods to model such flows. We focus on a range of Reynolds numbers, covering the inertial regime through the asymptotic turbulent regime. The review emphasizes both numerical modeling and the development of averaged (spatially filtered) balances over representative volumes of media. For modeling the pore scale, we examine the recent literature on Reynolds-averaged Navier–Stokes (

APA, Harvard, Vancouver, ISO, and other styles

22

Uddin, M. A., C. Kato, N. Oshima, M. Tanahashi, and T. Miyauchi. "Performance of the Finite Element and Finite Volume Methods for Large Eddy Simulation in Homogeneous Isotropic Turbulence." Journal of Scientific Research 2, no. 2 (2010): 237–49. http://dx.doi.org/10.3329/jsr.v2i2.2582.

Full text

Abstract:

Large eddy simulation (LES) in homogeneous isotropic turbulence is performed by using the Finite element method (FEM) and Finite volume vethod (FVM) and the results are compared to show the performance of FEM and FVM numerical solvers. The validation tests are done by using the standard Smagorinsky model (SSM) and dynamic Smagorinsky model (DSM) for subgrid-scale modeling. LES is performed on a uniformly distributed 643 grids and the Reynolds number is low enough that the computational grid is capable of resolving all the turbulence scales. The LES results are compared with those from direct n

APA, Harvard, Vancouver, ISO, and other styles

23

Weng, Chenyang, Susann Boij, and Ardeshir Hanifi. "Numerical and theoretical investigation of pulsatile turbulent channel flows." Journal of Fluid Mechanics 792 (February 29, 2016): 98–133. http://dx.doi.org/10.1017/jfm.2016.73.

Full text

Abstract:

A turbulent channel flow subjected to imposed harmonic oscillations is studied by direct numerical simulation (DNS) and theoretical models. Simulations have been performed for different pulsation frequencies. The time- and phase-averaged data have been used to analyse the flow. The onset of nonlinear effects during the production of the perturbation Reynolds stresses is discussed based on the DNS data, and new physical features observed in the DNS are reported. A linear model proposed earlier by the present authors for the coherent perturbation Reynolds shear stress is reviewed and discussed i

APA, Harvard, Vancouver, ISO, and other styles

24

Oder, Jure, Cédric Flageul, and Iztok Tiselj. "Statistical Uncertainty of DNS in Geometries without Homogeneous Directions." Applied Sciences 11, no. 4 (2021): 1399. http://dx.doi.org/10.3390/app11041399.

Full text

Abstract:

In this paper, we present uncertainties of statistical quantities of direct numerical simulations (DNS) with small numerical errors. The uncertainties are analysed for channel flow and a flow separation case in a confined backward facing step (BFS) geometry. The infinite channel flow case has two homogeneous directions and this is usually exploited to speed-up the convergence of the results. As we show, such a procedure reduces statistical uncertainties of the results by up to an order of magnitude. This effect is strongest in the near wall regions. In the case of flow over a confined BFS, the

APA, Harvard, Vancouver, ISO, and other styles

25

Krettenauer, Kilian, and Ulrich Schumann. "Numerical simulation of turbulent convection over wavy terrain." Journal of Fluid Mechanics 237 (April 1992): 261–99. http://dx.doi.org/10.1017/s0022112092003410.

Full text

Abstract:

Thermal convection of a Boussinesq fluid in a layer confined between two infinite horizontal walls is investigated by direct numerical simulation (DNS) and by large-eddy simulation (LES) for zero horizontal mean motion. The lower-surface height varies sinusoidally in one horizontal direction while remaining constant in the other. Several cases are considered with amplitude δ up to 0.15H and wavelength λ of H to 8H (inclination up to 43°), where H is the mean fluid-layer height. Constant heat flux is prescribed at the lower surface of the initially at rest and isothermal fluid layer. In the LES

APA, Harvard, Vancouver, ISO, and other styles

26

Jonker, Harm J. J., Maarten van Reeuwijk, Peter P. Sullivan, and Edward G. Patton. "On the scaling of shear-driven entrainment: a DNS study." Journal of Fluid Mechanics 732 (August 30, 2013): 150–65. http://dx.doi.org/10.1017/jfm.2013.394.

Full text

Abstract:

AbstractThe deepening of a shear-driven turbulent layer penetrating into a stably stratified quiescent layer is studied using direct numerical simulation (DNS). The simulation design mimics the classical laboratory experiments by Kato & Phillips (J. Fluid Mech., vol. 37, 1969, pp. 643–655) in that it starts with linear stratification and applies a constant shear stress at the lower boundary, but avoids sidewall and rotation effects inherent in the original experiment. It is found that the layers universally deepen as a function of the square root of time, independent of the initial stratif

APA, Harvard, Vancouver, ISO, and other styles

27

Watanabe, Takahiro, and Mikio Sakai. "Numerical Simulation of Magnetorheological Fluid with DEM-DNS Method." Journal of the Society of Powder Technology, Japan 55, no. 8 (2018): 426–32. http://dx.doi.org/10.4164/sptj.55.426.

Full text

APA, Harvard, Vancouver, ISO, and other styles

28

Marlatt, Stuart, Scott Waggy, and Sedat Biringen. "Direct Numerical Simulation of the Turbulent Ekman Layer: Evaluation of Closure Models." Journal of the Atmospheric Sciences 69, no. 3 (2012): 1106–17. http://dx.doi.org/10.1175/jas-d-11-0107.1.

Full text

Abstract:

Abstract A direct numerical simulation (DNS) at a Reynolds number of 1000 was performed for the neutral atmospheric boundary layer (ABL) using the Ekman layer approximation. The DNS results were used to evaluate several closure approximations that model the turbulent stresses in the Reynolds averaged momentum equations. Two first-order closure equations proposed by O’Brien and by Large, McWilliams, and Doney were tested; both models approximate the eddy diffusivity as a function of height using cubic polynomials. Of these two models, the O’Brien model, which requires data both at the surface l

APA, Harvard, Vancouver, ISO, and other styles

29

Kazemi, Ehsan, and Stefan Heinz. "Dynamic Large Eddy Simulations of the Ekman Layer Based on Stochastic Analysis." International Journal of Nonlinear Sciences and Numerical Simulation 17, no. 2 (2016): 77–98. http://dx.doi.org/10.1515/ijnsns-2015-0049.

Full text

Abstract:

AbstractLarge eddy simulation (LES) of the neutrally stratified turbulent Ekman layer is performed. In particular, we compare three LES models with direct numerical simulation (DNS), which was validated against existing DNS. The models considered are a standard nondynamic LES model, the Smagorinsky model (SM), a standard dynamic LES model, the stabilized dynamic Smagorinsky model (DSM), and a new linear dynamic model (LDM), which was derived from a realizable stochastic turbulence model. The following conclusions are obtained. The SM does not represent an appropriate model for the flow conside

APA, Harvard, Vancouver, ISO, and other styles

30

Ali, Md Shahjahan, Takashi Hosoda, and Ichiro Kimura. "Unsteady RANS and LES Simulation of an Ideal Rankine Vortex Decay." Advances in Civil Engineering 2012 (2012): 1–8. http://dx.doi.org/10.1155/2012/523839.

Full text

Abstract:

The 3D numerical simulation was carried out for an idealized Rankine vortex using nonlineark-εmodel (one kind of RANS model) and large eddy simulation (LES) techniques. In this 3D simulation, the vortex flow field was given to rotate with the vertical axis in a free surface rectangular domain. In order to investigate the predictability of standard (linear) and non-lineark-εmodels, the decay of a trailing vortex was simulated and compared with previous DNS data. The governing equations for mean velocities and turbulent flows were discretized with the finite volume method based on a staggered gr

APA, Harvard, Vancouver, ISO, and other styles

31

Suzuki, Takao. "Reduced-order Kalman-filtered hybrid simulation combining particle tracking velocimetry and direct numerical simulation." Journal of Fluid Mechanics 709 (August 20, 2012): 249–88. http://dx.doi.org/10.1017/jfm.2012.334.

Full text

Abstract:

AbstractThe capability of state-of-the-art techniques integrating experimental and computational fluid dynamics has been expanding recently. In our previous study, we have developed a hybrid unsteady-flow simulation technique combining particle tracking velocimetry (PTV) and direct numerical simulation (DNS) and demonstrated its capability at low Reynolds numbers. Similar approaches have also been proposed by a few groups; however, applying algorithms of this type generally becomes more challenging with increasing Reynolds number because the time interval of the frame rate for particle image v

APA, Harvard, Vancouver, ISO, and other styles

32

Parkinson, S. D., J. Hill, M. D. Piggott, and P. A. Allison. "Direct numerical simulations of particle-laden density currents with adaptive, discontinuous finite elements." Geoscientific Model Development Discussions 7, no. 3 (2014): 3219–64. http://dx.doi.org/10.5194/gmdd-7-3219-2014.

Full text

Abstract:

Abstract. High resolution direct numerical simulations (DNS) are an important tool for the detailed analysis of turbidity current dynamics. Models that resolve the vertical structure and turbulence of the flow are typically based upon the Navier–Stokes equations. Two-dimensional simulations are known to produce unrealistic cohesive vortices that are not representative of the real three-dimensional physics. The effect of this phenomena is particularly apparent in the later stages of flow propagation. The ideal solution to this problem is to run the simulation in three dimensions but this is com

APA, Harvard, Vancouver, ISO, and other styles

33

CARPENTER, J. R., E. W. TEDFORD, M. RAHMANI, and G. A. LAWRENCE. "Holmboe wave fields in simulation and experiment." Journal of Fluid Mechanics 648 (April 7, 2010): 205–23. http://dx.doi.org/10.1017/s002211200999317x.

Full text

Abstract:

The basic wave field resulting from Holmboe's instability is studied both numerically and experimentally. Comparisons between the direct numerical simulations (DNS) and laboratory experiments result in Holmboe waves that are similar in their appearance and phase speed. However, different boundary conditions result in mean flows that display gradual variations either temporally (in the simulations) or spatially (in the experiments). These differences are found to affect the evolution of the dominant wavenumber and amplitude of the wave field. The simulations exhibit a nonlinear ‘wave coarsening

APA, Harvard, Vancouver, ISO, and other styles

34

NIKITIN, NIKOLAY. "On the rate of spatial predictability in near-wall turbulence." Journal of Fluid Mechanics 614 (October 16, 2008): 495–507. http://dx.doi.org/10.1017/s0022112008003741.

Full text

Abstract:

Spatial evolution of small perturbations introduced into an inlet cross-section of fully developed turbulent flow in a long straight circular pipe is investigated via direct numerical simulation (DNS). The turbulent inflow field is extracted from an auxiliary streamwise-periodic simulation running in parallel with the main spatial simulation. It is shown that mean perturbation amplitude ϵ increases exponentially with distance downstream. The growth rate is found to be constant when normalized by viscous length, ϵ ~ exp(0.0021x+) over the considered Reynolds-number range 140 ≤ Reτ ≤ 320. The un

APA, Harvard, Vancouver, ISO, and other styles

35

Uchiyama, Tomomi, Yutaro Yoshii, and Hirotaka Hamada. "Direct numerical simulation of a turbulent channel flow by an improved vortex in cell method." International Journal of Numerical Methods for Heat & Fluid Flow 24, no. 1 (2013): 103–23. http://dx.doi.org/10.1108/hff-01-2012-0010.

Full text

Abstract:

Purpose – This study is concerned with the direct numerical simulation (DNS) of a turbulent channel flow by an improved vortex in cell (VIC) method. The paper aims to discuss these issues. Design/methodology/approach – First, two improvements for VIC method are proposed to heighten the numerical accuracy and efficiency. A discretization method employing a staggered grid is presented to ensure the consistency among the discretized equations as well as to prevent the numerical oscillation of the solution. A correction method for vorticity is also proposed to compute the vorticity field satisfyin

APA, Harvard, Vancouver, ISO, and other styles

36

Chung, D., L. Chan, M. MacDonald, N. Hutchins, and A. Ooi. "A fast direct numerical simulation method for characterising hydraulic roughness." Journal of Fluid Mechanics 773 (May 26, 2015): 418–31. http://dx.doi.org/10.1017/jfm.2015.230.

Full text

Abstract:

We describe a fast direct numerical simulation (DNS) method that promises to directly characterise the hydraulic roughness of any given rough surface, from the hydraulically smooth to the fully rough regime. The method circumvents the unfavourable computational cost associated with simulating high-Reynolds-number flows by employing minimal-span channels (Jiménez & Moin, J. Fluid Mech., vol. 225, 1991, pp. 213–240). Proof-of-concept simulations demonstrate that flows in minimal-span channels are sufficient for capturing the downward velocity shift, that is, the Hama roughness function, pred

APA, Harvard, Vancouver, ISO, and other styles

37

Rodi, W., та N. N. Mansour. "Low Reynolds number k—ε modelling with the aid of direct simulation data". Journal of Fluid Mechanics 250 (травень 1993): 509–29. http://dx.doi.org/10.1017/s0022112093001545.

Full text

Abstract:

The constant Cμ and the near-wall damping function fμ in the eddy-viscosity relation of the k–ε model are evaluated from direct numerical simulation (DNS) data for developed channel and boundary-layer flow, each at two Reynolds numbers. Various existing fμ model functions are compared with the DNS data, and a new function is fitted to the high-Reynolds-number channel flow data. The ε-budget is computed for the fully developed channel flow. The relative magnitude of the terms in the ε-equation is analysed with the aid of scaling arguments, and the parameter governing this magnitude is establish

APA, Harvard, Vancouver, ISO, and other styles

38

Wang, Zheng. "Analysis of DNS Cache Effects on Query Distribution." Scientific World Journal 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/938418.

Full text

Abstract:

This paper studies the DNS cache effects that occur on query distribution at the CN top-level domain (TLD) server. We first filter out the malformed DNS queries to purify the log data pollution according to six categories. A model for DNS resolution, more specifically DNS caching, is presented. We demonstrate the presence and magnitude of DNS cache effects and the cache sharing effects on the request distribution through analytic model and simulation. CN TLD log data results are provided and analyzed based on the cache model. The approximate TTL distribution for domain name is inferred quantif

APA, Harvard, Vancouver, ISO, and other styles

39

Jiang, Siya, and Song Fu. "Modifications to the SIMPLE algorithm with the MDCD approach for incompressible flow simulation." International Journal of Numerical Methods for Heat & Fluid Flow 28, no. 9 (2018): 2208–30. http://dx.doi.org/10.1108/hff-02-2018-0054.

Full text

Abstract:

Purpose The purpose of the paper is to propose some modifications to the SIMPLE (semi-implicit method for pressure-linked equations) algorithm. These modifications can ensure the numerical robustness and optimize computational efficiency. They remarkably promote the ability of the SIMPLE algorithm for incompressible DNS (direct numerical simulation) of multiscale problems, such as transitional flows and turbulent flows, by improving the properties of dispersion and dissipation. Design/methodology/approach The MDCD (minimized dispersion and controllable dissipation) scheme and MMIM (modified mo

APA, Harvard, Vancouver, ISO, and other styles

40

MONTY, J. P., and M. S. CHONG. "Turbulent channel flow: comparison of streamwise velocity data from experiments and direct numerical simulation." Journal of Fluid Mechanics 633 (August 25, 2009): 461–74. http://dx.doi.org/10.1017/s0022112009007769.

Full text

Abstract:

Recently there has been remarkable progress made in the direct numerical simulation (DNS) of wall-bounded turbulence, particularly of turbulent channel flow, with numerical data now available above Reτ ≈ 2000 (Hoyas & Jiménez, Phys. Fluids, vol. 18, 2006, p. 011702; Iwamoto et al., Proceedings of the Sixth Symposium Smart Control of Turbulence, 2005). Much knowledge has been gained from these results, particularly in the areas of flow structure and dynamics. Yet, while the value of such simulations is undoubted, only very limited comparisons with experimental data have been documented. Alt

APA, Harvard, Vancouver, ISO, and other styles

41

Shen, Yu Hui, and Han Zhou Hao. "A Simulation of E-Commerce with Gnat." Applied Mechanics and Materials 278-280 (January 2013): 1994–97. http://dx.doi.org/10.4028/www.scientific.net/amm.278-280.1994.

Full text

Abstract:

DNS and the location-identity split, while technical in theory, have not until recently been considered practical. In our research, we prove the synthesis of replication. In this paper we demonstrate that though link-level acknowledgements and the producer-consumer problem can synchronize to achieve this objective, SCSI disks can be made reliable, random, and ubiquitous.

APA, Harvard, Vancouver, ISO, and other styles

42

Parneix, S., D. Laurence, and P. A. Durbin. "A Procedure for Using DNS Databases." Journal of Fluids Engineering 120, no. 1 (1998): 40–47. http://dx.doi.org/10.1115/1.2819658.

Full text

Abstract:

A second moment closure (SMC) computation is compared in detail with the direct numerical simulation (DNS) data of Le et al. (1997) for the backstep flow at Re = 5100 in an attempt to understand why the intensity of the backflow and, consequently, the friction coefficient in the recirculation bubble are under-estimated. The data show that this recirculation bubble is far from being laminar except in the very near wall layer. A novel “differential a priori” procedure was used, in which the full transport equation for one isolated component of the Reynolds stress tensor was solved using DNS data

APA, Harvard, Vancouver, ISO, and other styles

43

Witkowska, A., D. Juvé, and J. G. Brasseur. "Numerical Study of Noise from Isotropic Turbulence." Journal of Computational Acoustics 05, no. 03 (1997): 317–36. http://dx.doi.org/10.1142/s0218396x97000186.

Full text

Abstract:

A numerical study of sound radiation by isotropic turbulence is carried out by combining turbulence simulation with Lighthill's acoustic analogy. In the first study we analyze sound generation by decaying isotropic turbulence obtained both with 643 Direct Numerical Simulation (DNS) and 163 Large Eddy Simulation (LES). Both simulations lead to similar results for acoustic power, in agreement with the numerical results of Sarkar and Hussaini, but slightly different from theoretical predictions of Proudman and Lilley. In the second study we analyze sound generation by forced stationary turbulence

APA, Harvard, Vancouver, ISO, and other styles

44

LUO, K. H., J. XIA, and E. MONACO. "MULTISCALE MODELING OF MULTIPHASE FLOW WITH COMPLEX INTERACTIONS." Journal of Multiscale Modelling 01, no. 01 (2009): 125–56. http://dx.doi.org/10.1142/s1756973709000074.

Full text

Abstract:

This paper presents a variety of modeling and simulation methods for complex multiphase flow at microscopic, mesoscopic and macroscopic scales. Each method is discussed in terms of its scale-resolving capability and its relationship with other approaches. Examples of application are provided using a liquid–gas system, in which complex multiscale interactions exist among flow, turbulence, combustion and droplet dynamics. Large eddy simulation (LES) is employed to study the effects of a very large number of droplets on turbulent combustion in two configurations in a fixed laboratory frame. Direc

APA, Harvard, Vancouver, ISO, and other styles

45

Wang. "Reynolds Stress Model for Viscoelastic Drag-Reducing Flow Induced by Polymer Solution." Polymers 11, no. 10 (2019): 1659. http://dx.doi.org/10.3390/polym11101659.

Full text

Abstract:

Viscoelasticity drag-reducing flow by polymer solution can reduce pumping energy of pipe flow significantly. One of the simulation manners is direct numerical simulation (DNS). However, the computational time is too long to accept in engineering. Turbulent model is a powerful tool to solve engineering problems because of its fast computational ability. However, its precision is usually low. To solve this problem, we introduce DNS to provide accurate data to construct a high-precision turbulent model. A Reynolds stress model for viscoelastic polymer drag-reducing flow is established. The rheolo

APA, Harvard, Vancouver, ISO, and other styles

46

Elghobashi, Said. "Direct Numerical Simulation of Turbulent Flows Laden with Droplets or Bubbles." Annual Review of Fluid Mechanics 51, no. 1 (2019): 217–44. http://dx.doi.org/10.1146/annurev-fluid-010518-040401.

Full text

Abstract:

This review focuses on direct numerical simulations (DNS) of turbulent flows laden with droplets or bubbles. DNS of these flows are more challenging than those of flows laden with solid particles due to the surface deformation in the former. The numerical methods discussed are classified by whether the initial diameter of the bubble/droplet is smaller or larger than the Kolmogorov length scale and whether the instantaneous surface deformation is fully resolved or obtained via a phenomenological model. Also discussed are numerical methods that account for the breakup of a single droplet or bubb

APA, Harvard, Vancouver, ISO, and other styles

47

Feng, Zhi-Gang, and Efstathios E. Michaelides. "Heat transfer in particulate flows with Direct Numerical Simulation (DNS)." International Journal of Heat and Mass Transfer 52, no. 3-4 (2009): 777–86. http://dx.doi.org/10.1016/j.ijheatmasstransfer.2008.07.023.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Bassi, Caterina, Antonella Abbà, Luca Bonaventura, and Lorenzo Valdettaro. "Large Eddy Simulation of gravity currents with a high order DG method." Communications in Applied and Industrial Mathematics 8, no. 1 (2017): 128–48. http://dx.doi.org/10.1515/caim-2017-0007.

Full text

Abstract:

Abstract This work deals with Direct Numerical Simulations (DNS) and Large Eddy Simulations (LES) of a turbulent gravity current in a gas, performed by means of a Discontinuous Galerkin (DG) Finite Elements method employing, in the LES case, LES-DG turbulence models previously introduced by the authors. Numerical simulations of non-Boussinesq lock-exchange benchmark problems show that, in the DNS case, the proposed method allows to correctly reproduce relevant features of variable density gas ows with gravity. Moreover, the LES results highlight, also in this context, the excessively high diss

APA, Harvard, Vancouver, ISO, and other styles

49

Fasel, Hermann F., Dominic A. von Terzi, and Richard D. Sandberg. "A Methodology for Simulating Compressible Turbulent Flows." Journal of Applied Mechanics 73, no. 3 (2005): 405–12. http://dx.doi.org/10.1115/1.2150231.

Full text

Abstract:

A flow simulation Methodology (FSM) is presented for computing the time-dependent behavior of complex compressible turbulent flows. The development of FSM was initiated in close collaboration with C. Speziale (then at Boston University). The objective of FSM is to provide the proper amount of turbulence modeling for the unresolved scales while directly computing the largest scales. The strategy is implemented by using state-of-the-art turbulence models (as developed for Reynolds averaged Navier-Stokes (RANS)) and scaling of the model terms with a “contribution function.” The contribution funct

APA, Harvard, Vancouver, ISO, and other styles

50

Radhakrishnan, Senthilkumaran, and Josette Bellan. "Explicit filtering to obtain grid-spacing-independent and discretization-order-independent large-eddy simulation of compressible single-phase flow." Journal of Fluid Mechanics 697 (March 6, 2012): 399–435. http://dx.doi.org/10.1017/jfm.2012.73.

Full text

Abstract:

AbstractIn large-eddy simulation (LES), it is often assumed that the filter width is equal to the grid spacing. Predictions from such LES are grid-spacing dependent since any subgrid-scale (SGS) model used in the LES equations is dependent on the resolved flow field which itself varies with grid spacing. Moreover, numerical errors affect the flow field, especially the smallest resolved scales. Thus, predictions using this approach are affected by both modelling and numerical choices. However, grid-spacing-independent LES predictions unaffected by numerical choices are necessary to validate LES

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!