Lattice Boltzmann method for adiabatic acoustics

2011 ◽  
Vol 369 (1944) ◽  
pp. 2371-2380 ◽  
Author(s):  
Yanbing Li ◽  
Xiaowen Shan
Keyword(s):  
Fluid Dynamics ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Collision Frequency ◽  
Low Frequency ◽  
Navier Stokes ◽  
Sound Waves ◽  
Frequency Limit ◽  
Molecular Collision ◽  
Boltzmann Method

The lattice Boltzmann method (LBM) has been proved to be a useful tool in many areas of computational fluid dynamics, including computational aero-acoustics (CAA). However, for historical reasons, its applications in CAA have been largely restricted to simulations of isothermal (Newtonian) sound waves. As the recent kinetic theory-based reformulation establishes a theoretical framework in which LBM can be extended to recover the full Navier–Stokes–Fourier (NS) equations and beyond, in this paper, we show that, at least at the low-frequency limit (sound frequency much less than molecular collision frequency), adiabatic sound waves can be accurately simulated by the LBM provided that the lattice and the distribution function ensure adequate recovery of the full NS equations.

scholarly journals Modelling dan Pembuatan Algoritma Aliran Fluida pada External Ballistics dengan Model G1-Standard-Bullet Menggunalan Metode Lattice Boltzmann

Respati ◽  
2017 ◽  
Vol 12 (3) ◽  
Author(s):  
Kumara Ari Yuana
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Navier Stokes ◽  
Continuum Equation ◽  
The World ◽  
Rational Explanation ◽  
Boltzmann Method ◽  
Network Pattern

 INTISARIKomputasi dan eksperimental dalam dunia teknik permesinan (mechanical engineer) merupakan bidang yang saling melengkapi. Komputasi dilakukan untuk memberikan gambaran dan penjelasan rasional dari fenomena yang dihasilkan pada eksperimen. Komputasi juga memberikan prediksi sebelum dilakukan eksperimen untuk lebih mematangkan kondisi-kondisi dari sebuah eksperimen. Komputasi dengan metode Lattice Boltzmann adalah metode yang relatif baru dan menjanjikan di dunia komputasi aliran fluida atau CFD (Computational Fluid Dynamics), sebagai alternative metode yang sudah lama dikembangkan dari persamaan kontunum Navier-Stokes. Metode Lattice Boltzmann berangkat dari logika interaksi sekumpulan partikel dan ditelusuri pola interaksinya melalui bantuan pola jaringan (lattice). Pada riset ini akan digunakan metode Lattice Boltzmann untuk membuat model matematis dan algoritmanya pad aliran fluida yang mengalir di sekitar External Ballistics model G1-Standard-Bullet. Tahap riset selanjutnya adalah pengembangan pembuatan coding pemrograman dan simulasi visual untuk mengetahui pola aliran dan analisis-analisis aerodinamisnya. ABSTRACTComputational and experimental in the world of mechanical engineering is a complementary field and providing a picture and a rational explanation of the phenomena generated from the experiment. Computation with the Lattice Boltzmann method is a relatively new and promising method in the world of fluid flow computation or CFD (Computational Fluid Dynamics), as an alternative to the long-established method of the Navier-Stokes continuum equation. The Lattice Boltzmann method departs from the logic of the interaction of a set of particles and traces its interaction pattern through the aid of a network pattern (lattice). In this research we will use the Lattice Boltzmann method to create a mathematical model and algorithm for the flow of fluid flowing around External Ballistics model G1-Standard-Bullet. The next stage of research is developing the development of coding programming and visual simulation to know the flow pattern and aerodynamic analysis.

scholarly journals Involving the Navier–Stokes equations in the derivation of boundary conditions for the lattice Boltzmann method

2011 ◽  
Vol 369 (1944) ◽  
pp. 2184-2192 ◽  
Author(s):  
Joris C. G. Verschaeve
Keyword(s):  
Boundary Condition ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Stokes Equations ◽  
Slip Boundary Condition ◽  
Navier Stokes ◽  
Grid Spacing ◽  
Navier Stokes Equations ◽  
Slip Boundary ◽  
Boltzmann Method

By means of the continuity equation of the incompressible Navier–Stokes equations, additional physical arguments for the derivation of a formulation of the no-slip boundary condition for the lattice Boltzmann method for straight walls at rest are obtained. This leads to a boundary condition that is second-order accurate with respect to the grid spacing and conserves mass. In addition, the boundary condition is stable for relaxation frequencies close to two.

Numerical Simulation of High Reynolds Number Flow Structure in a Lid-Driven Cavity Using MRT-LES

2014 ◽  
Vol 554 ◽  
pp. 665-669
Author(s):  
Leila Jahanshaloo ◽  
Nor Azwadi Che Sidik
Keyword(s):  
Reynolds Number ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Numerical Technique ◽  
Lattice Boltzmann Model ◽  
Navier Stokes ◽  
Navier Stokes Equation ◽  
Driven Cavity ◽  
Reynolds Number Flow ◽  
Boltzmann Method

The Lattice Boltzmann Method (LBM) is a potent numerical technique based on kinetic theory, which has been effectively employed in various complicated physical, chemical and fluid mechanics problems. In this paper multi-relaxation lattice Boltzmann model (MRT) coupled with a Large Eddy Simulation (LES) and the equation are applied for driven cavity flow at different Reynolds number (1000-10000) and the results are compared with the previous published papers which solve the Navier stokes equation directly. The comparisons between the simulated results show that the lattice Boltzmann method has the capacity to solve the complex flows with reasonable accuracy and reliability. Keywords: Two-dimensional flows, Lattice Boltzmann method, Turbulent flow, MRT, LES.

Numerical Investigation of Flow Over an Airfoil by the Lattice Boltzmann Method

2013 ◽  
Author(s):  
Felipe A. Valenzuela ◽  
Amador M. Guzmán ◽  
Andrés J. Díaz
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Preliminary Investigation ◽  
Computational Cost ◽  
Fluid Flows ◽  
Laminar Flows ◽  
Navier Stokes ◽  
Laminar Separation ◽  
Refinement Method ◽  
Boltzmann Method

During the last years the aerodynamics characteristics of airfoils have been studied solving numerically the Navier-Stokes (NS) equations. These calculations require a significant computational cost due to both the second order and the nonlinear characteristics of the NS partial differential equations. Therefore, efforts have been devoted to reduce this cost and increase the accuracy of the numerical methods. The Lattice-Boltzmann Method (LBM) has become a great alternative to simulate this problem and a variety of fluid flows. In this method, the convective operator is linear and the pressure is calculated directly by the equation of state without implementing iterative methods. This work represents a preliminary investigation of a laminar flow over airfoils under low Reynolds number conditions (Re = 500). Solutions are obtained using a Multi-Block mesh refinement method. In order to validate the computational code, calculations are performed on a SD7003 airfoil at an angle of attack of 4° and 30°, which corresponds to the available numerical and experimental results. The results of this study agree well with previous experimental and numerical studies demonstrating the capabilities of the LBM to simulate accurately laminar flows over airfoils as well as capturing and predicting the laminar separation bubbles.

scholarly journals Flow Visualization of Spinning and Nonspinning Soccer Balls Using Computational Fluid Dynamics

2020 ◽  
Vol 10 (13) ◽  
pp. 4543 ◽  
Author(s):  
Takeshi Asai ◽  
Yasumi Nakanishi ◽  
Nakaba Akiyama ◽  
Sungchan Hong
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Lattice Boltzmann Method ◽  
Vortex Structure ◽  
Lattice Boltzmann ◽  
Large Scale ◽  
Vortex Pair ◽  
Vortex Structures ◽  
Soccer Ball ◽  
Boltzmann Method

Various studies have been conducted on the aerodynamic characteristics of nonspinning and spinning soccer balls. However, the vortex structures in the wake of the balls are almost unknown. One of the main computational fluid dynamics methods used for the analysis of vortex structures is the lattice Boltzmann method as it facilitates high-precision analysis. Studies to elucidate the dominant vortex structure are important because curled shots and passes involving spinning balls are frequently used in actual soccer games. In this study, we identify the large-scale dominant vortex structure of a soccer ball and investigate the stability of the structure using the lattice Boltzmann method, wind tunnel tests, and free-flight experiments. One of the dominant vortex structures in the wake of both nonspinning and spinning balls is a large-scale counter-rotating vortex pair. The side force acting on a spinning ball stabilizes when the fluctuation of the separation points of the ball is suppressed by the rotation of the ball. Thus, although a spinning soccer ball is deflected by the Magnus effect, its trajectory is regular and stable, suggesting that a spinning ball can be aimed accurately at the outset of its course.

A Micro-Channel Flow and Heat Transfer Study by Lattice Boltzmann Method

2003 ◽  
Author(s):  
Ru Yang ◽  
Chin-Sheng Wang
Keyword(s):  
Heat Transfer ◽  
Lattice Boltzmann Method ◽  
Channel Flow ◽  
Lattice Boltzmann ◽  
Slip Flow ◽  
Navier Stokes ◽  
Micro Channel ◽  
Parallel Plates ◽  
Boltzmann Method ◽  
Good Agreement

A Lattice Boltzmann method is employed to investigate the flow characteristics and the heat transfer phenomenon between two parallel plates separated by a micro-gap. A nine-velocity model and an internal energy distribution model are used to obtain the mass, momentum and temperature distributions. It is shown that for small Knudsen numbers (Kn), the current results are in good agreement with those obtained from the traditional Navier-Stokes equation with non-slip boundary conditions. As the value of Kn is increased, it is found that the non-slip condition may no longer be valid at the wall boundary and that the flow behavior changes to one of slip-flow. In slip flow regime, the present results is still in good agreement with slip-flow solution by Navier Stokes equations. The non-linear nature of the pressure and friction distribution for micro-channel flow is gieven. Finally, the current investigation presents a prediction of the temperature distribution for micro-channel flow under the imposed conditions of an isothermal boundary.

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