Simulation of Sound Generation by Flow over a Cavity with the Lattice Boltzmann Method

2012 ◽  
Vol 184-185 ◽  
pp. 456-459
Author(s):  
Shan Ling Han ◽  
Li Sha Yu ◽  
Gui Shen Wang ◽  
Qing Liang Zeng
Keyword(s):  
Shear Layer ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Fluid Flows ◽  
Cavity Resonance ◽  
Aerodynamic Noise ◽  
Mesoscopic Models ◽  
Flow Through ◽  
Flow Over A Cavity ◽  
Boltzmann Method

The fluid flows and its related aerodynamic noise are very common in the nature and the engineering fieds. Lattice Boltzmann Method (LBM), which is based on the mesoscopic models, is a new CFD approach. It has the congenital superiority and the inestimable development potential in the simulation of complex fluid flow. Referring to the experimental results provided by NASA/CP 2004-212954, the aerodynamic noise produced by the flow through a cavity is simulated by the lattice Boltzmann method. The results had vividly demonstrated the shear layer oscillations, the couple between the shear layer oscillations and cavity resonance pattern. This simulation has discovered that the shear layer oscillation is the main reason for the production of cavity aerodynamic noise. The simulation results are consistent with the NASA experiment data.

Application of the Lattice-Boltzmann-Method in Two-Phase Flow Studies: From Point-Particles to Fully Resolved Particles

2011 ◽  
Author(s):  
M. Dietzel ◽  
M. Ernst ◽  
M. Sommerfeld
Keyword(s):  
Boundary Condition ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Fluid Flows ◽  
Two Phase ◽  
Primary Particles ◽  
Local Grid ◽  
Numerical Grid ◽  
Flow Through ◽  
Boltzmann Method

The Lattice-Boltzmann-Method (LBM) is a powerful and robust approach for calculating fluid flows in complex geometries. This method was further developed for allowing the calculation of several problems relevant to particle-laden flows. For that purpose two approaches have been developed. The first approach concerns the coupling of the LBM with a classical Lagrangian procedure where the particles are considered as point-masses and hence the particles and the flow around them are numerically not resolved. As an example of use, the flow through a single pore was considered and the deposition of nano-scale particles was simulated. The temporal evolution of the deposit structures is visualised and both the filtration efficiency and the pressure drop are simulated and compared with measurements. In the second developed LBM-approach, the particles are fully resolved by the numerical grid whereby the flow around particles is also captured and it is possibly to effectively calculate the forces on complex particles from the bounce-back boundary condition. As a case study the flow around spherical agglomerates consisting of mono-sized spherical primary particles is examined. Using local grid refinement and the curved wall boundary condition accurate simulations of the drag coefficient of such complex particles could be performed. Especially the effect of porosity on the drag was analysed. Finally, a scenario with moving particles was considered, namely, the sedimentation of a cluster of particles. In these simulations the primary particles were allowed to stick together and form agglomerates.

Simulation of Hypersonic Viscous Flow Past a 2D Circular Cylinder Using Lattice Boltzmann Method

2010 ◽  
Author(s):  
R. Kamali ◽  
A. H. Tabatabaee Frad
Keyword(s):  
Circular Cylinder ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
High Speed ◽  
Fluid Flows ◽  
Boltzmann Distribution ◽  
Equilibrium Distribution Function ◽  
Complex Flows ◽  
Compressible Viscous Flows ◽  
Boltzmann Method

It is known that the Lattice Boltzmann Method is not very effective when it is being used for the high speed compressible viscous flows; especially complex fluid flows around bodies. Different reasons have been reported for this unsuccessfulness; Lacking in required isotropy in the employed lattices and the restriction of having low Mach number in Taylor expansion of the Maxwell Boltzmann distribution as the equilibrium distribution function, might be mentioned as the most important ones. In present study, a new numerical method based on Li et al. scheme is introduced which enables the Lattice BoltzmannMethod to stably simulate the complex flows around a 2D circular cylinder. Furthermore, more stable implementation of boundary conditions in Lattice Boltzmann method is discussed.

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.

A Meshfree-Based Lattice Boltzmann Approach for Simulation of Fluid Flows Within Complex Geometries

2018 ◽  
pp. 188-222 ◽  
Author(s):  
Sonam Tanwar
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Moving Boundary ◽  
Fluid Flows ◽  
Computational Domain ◽  
Time Step ◽  
Boundary Problems ◽  
Complex Process ◽  
Element Free ◽  
Boltzmann Method

This chapter develops a meshless formulation of lattice Boltzmann method for simulation of fluid flows within complex and irregular geometries. The meshless feature of proposed technique will improve the accuracy of standard lattice Boltzmann method within complicated fluid domains. Discretization of such domains itself may introduce significant numerical errors into the solution. Specifically, in phase transition or moving boundary problems, discretization of the domain is a time-consuming and complex process. In these problems, at each time step, the computational domain may change its shape and need to be re-meshed accordingly for the purpose of accuracy and stability of the solution. The author proposes to combine lattice Boltzmann method with a Galerkin meshfree technique popularly known as element-free Galerkin method in this chapter to remove the difficulties associated with traditional grid-based methods.

Highly resolved pulsatile flows through prosthetic heart valves using the entropic lattice-Boltzmann method

2014 ◽  
Vol 754 ◽  
pp. 122-160 ◽  
Author(s):  
B. Min Yun ◽  
L. P. Dasi ◽  
C. K. Aidun ◽  
A. P. Yoganathan
Keyword(s):  
Lattice Boltzmann Method ◽  
Pulsatile Flow ◽  
Lattice Boltzmann ◽  
Heart Valves ◽  
Prosthetic Heart Valves ◽  
Spatiotemporal Resolution ◽  
Jude Medical ◽  
High Spatiotemporal Resolution ◽  
Flow Through ◽  
Boltzmann Method

AbstractProsthetic heart valves have been widely used to replace diseased or defective native heart valves. Flow through bileaflet mechanical heart valves (BMHVs) have previously demonstrated complex phenomena in the vicinity of the valve owing to the presence of two rigid leaflets. This study aims to accurately capture the complex flow dynamics for pulsatile flow through a 23 mm St Jude Medical (SJM) Regent™ BMHV. The lattice-Boltzmann method (LBM) is used to simulate pulsatile flow through the valve with the inclusion of reverse leakage flow at very high spatiotemporal resolution that can capture fine details in the pulsatile BMHV flow field. For higher-Reynolds-number flows, this high spatiotemporal resolution captures features that have not been observed in previous coarse resolution studies. In addition, the simulations are able to capture with detail the features of leaflet closing and the asymmetric b-datum leakage jet during mid-diastole. Novel flow physics are visualized and discussed along with quantification of turbulent features of this flow, which is made possible by this parallelized numerical method.

Lattice-Boltzmann Method for Macroscopic Porous Media Modeling

1998 ◽  
Vol 09 (08) ◽  
pp. 1491-1503 ◽  
Author(s):  
David M. Freed
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Inertial Effects ◽  
Simulation Region ◽  
Flow Through ◽  
Previous Algorithm ◽  
Validation Tests ◽  
Boltzmann Method

An extension to the basic lattice-BGK algorithm is presented for modeling a simulation region as a porous medium. The method recovers flow through a resistance field with arbitrary values of the resistance tensor components. Corrections to a previous algorithm are identified. Simple validation tests are performed which verify the accuracy of the method, and demonstrate that inertial effects give a deviation from Darcy's law for nominal simulation velocities.

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