A Confrontation of Lattice Boltzmann, Finite Difference and Taguchi Experimental Design Results for Optimizing Plasma Spraying Operating Conditions Toward Deposit Requirements

2017 ◽  
Vol 6 (4) ◽  
pp. 16-34 ◽  
Author(s):  
Ridha Djebali
Keyword(s):  
Experimental Design ◽  
Plasma Spraying ◽  
Lattice Boltzmann ◽  
Operating Conditions ◽  
Taguchi Experimental Design ◽  
Confirmation Test ◽  
Boltzmann Method ◽  
Impact Characteristics ◽  
Plasma Spraying Process ◽  
Good Agreement

The aim of the present work is the confrontation of three numerical techniques results to optimize the operating conditions of thermal plasma spraying process. The Lattice Boltzmann method (LBM) is used to scrutinize dispersion effects of injection parameters on droplet impact characteristics when impacting substrate. The validation of the developed model shows good agreement with former findings. The results of spraying Zirconia particles give the values Kmin=88.2, Kmax=367.4, Kmean=273.8 and a standard deviation of 48.0 for the Sommerfeld number. The Taguchi experimental design study is conducted for five operating parameters of two levels. The ensuing retained factors combination give Kmean=258.9. To assess drawn conclusions, confirmation test was performed using the Jets&Poudres software. The results show that the prior way is to coat and particles of dp< 40.3 µm have evaporated, particles 40.3 = dp = 49 µm are fully molten and all particles of dp = 71.9 µm arrive fully solid.

Using Taguchi Experimental Design to Investigate Operating Variables That Significantly Affect Wear in Mud Pumps

1995 ◽  
Vol 209 (1) ◽  
pp. 29-40
Author(s):  
S H Mok ◽  
D G Gorman
Keyword(s):  
Experimental Design ◽  
Normal Load ◽  
Drilling Fluid ◽  
Operating Conditions ◽  
Taguchi Experimental Design ◽  
Drilling Mud ◽  
Test Rig ◽  
Offshore Drilling ◽  
Wear Rates ◽  
Operating Variables

Maintenance of offshore drilling mud pumps is normally based on running hours. It is generally accepted, however, that time does not provide an accurate means of scheduling maintenance, given the varying operating conditions of the reciprocating mud pumps. The energy expended at the interaction of sliding surfaces is hypothesized to be a better alternative. The effects of operating variables on wear rates are investigated. A Taguchi experimental design was used to identify those factors that significantly affect wear. Within the confines of an experimental test rig, the normal load and abrasive sand content was found to have a significant effect on the specific wear rate of nitrile rubber sliding on steel in drilling fluid.

scholarly journals A Lattice Boltzmann Scheme for Diffusion Equation in Spherical Coordinate

2018 ◽  
Vol 1 (4) ◽  
Author(s):  
Debabrata Datta ◽  
T K Pal
Keyword(s):  
Diffusion Equation ◽  
Coordinate System ◽  
Lattice Boltzmann ◽  
Spherical Coordinate System ◽  
Cartesian Coordinate System ◽  
Spherical Coordinate ◽  
Cartesian Coordinate ◽  
Lattice Boltzmann Models ◽  
Boltzmann Method ◽  
Good Agreement

Lattice Boltzmann models for diffusion equation are generally in Cartesian coordinate system. Very few researchers have attempted to solve diffusion equation in spherical coordinate system. In the lattice Boltzmann based diffusion model in spherical coordinate system extra term, which is due to variation of surface area along radial direction, is modeled as source term. In this study diffusion equation in spherical coordinate system is first converted to diffusion equation which is similar to that in Cartesian coordinate system by using proper variable. The diffusion equation is then solved using standard lattice Boltzmann method. The results obtained for the new variable are again converted to the actual variable. The numerical scheme is verified by comparing the results of the simulation study with analytical solution. A good agreement between the two results is established.

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.

A NOVEL LESS DISSIPATION FINITE-DIFFERENCE LATTICE BOLTZMANN SCHEME FOR COMPRESSIBLE FLOWS

2012 ◽  
Vol 23 (11) ◽  
pp. 1250074 ◽  
Author(s):  
Q. CHEN ◽  
X. B. ZHANG
Keyword(s):  
Finite Difference ◽  
Lattice Boltzmann ◽  
Compressible Flows ◽  
Sufficient Conditions ◽  
Sufficient Conditions For Convergence ◽  
Necessary And Sufficient ◽  
Boltzmann Method ◽  
Lattice Boltzmann Scheme ◽  
Better Than ◽  
Good Agreement

In this paper, a new smoothness indicator is proposed to improve the finite-difference lattice Boltzmann method (FDLBM). The necessary and sufficient conditions for convergence are derived. A detailed analysis reveals that the convergence order is higher than that of the previous finite-difference scheme. The coupled double distribution function (DDF) model is used to describe discontinuity flows and verify the improvement. Numerical simulations of compressible flows with shock wave show that the improved finite-difference lattice Boltzmann scheme is accurate and has less dissipation. The numerical results are found to be in good agreement with the analytical results and better than those of the previous scheme.

Verification of a Lattice-Boltzmann Method by Using Analytical Flow Solutions of Standard Flow Problems

2009 ◽  
Author(s):  
Martin Bo¨hle ◽  
Richard Becker
Keyword(s):  
Boundary Layer ◽  
Analytical Solution ◽  
Lattice Boltzmann Method ◽  
Laminar Boundary Layer ◽  
Lattice Boltzmann ◽  
Boundary Layer Flow ◽  
Reynold Number ◽  
Layer Flow ◽  
Boltzmann Method ◽  
Good Agreement

Within the last ten years Lattice Boltzmann solvers have become very popular. They are used for flows inside complex geometries and around bodies like cars, for example. Lattice Boltzmann codes are easy to program because no complex linear equation systems must be solved. Furthermore it is easy to implement different kind of flow models, for example models for multiphase flows. The present paper points out the advantages of Lattice Boltmann methods by comparing results of the Lattice Boltzmann method with analytical and standard CFD results. Under standard CFD the application of a commercial CFD-code is meant. Two standard flows are considered. The first flow under consideration is the laminar boundary layer flow. For example, skin friction values calculated by both a standard CFD-code (FLUENT is applied) and a Lattice Boltzmann code are compared. For the laminar boundary layer flow an analytical solution is available. In the present paper all three results (analytical solution, FLUENT solution, Lattice Boltzmann solution) are compared and discussed. It is demonstrated that the results are in good agreement. Additionally, the 2D-flow around a cylinder for Reynold number 35 is considered. It is also demonstrated that the Lattice Boltzmann results are in good agreement with the results calculated by the application of FLUENT.

Isothermal Rectangular Roughness Elements in a Rectangular Cavity Heated at Bottom

2016 ◽  
Author(s):  
M. Yousaf ◽  
S. Usman
Keyword(s):  
Lattice Boltzmann ◽  
Computational Algorithm ◽  
Rectangular Cavity ◽  
Bgk Model ◽  
Maximum Reduction ◽  
Dimensionless Amplitude ◽  
Roughness Elements ◽  
Boltzmann Method ◽  
Good Agreement

The purpose of the present research was to explore the role of rectangular roughness elements during natural convection in a two-dimensional rectangular cavity. The computational algorithm was developed based on the single relaxation time Bhatnagr-Gross and Krook (BGK) model of lattice Boltzmann method (LBM). Rectangular roughness elements were located on the horizontal walls. The computational algorithm was validated against benchmark studies using different numerical techniques, and a good agreement was found to exist. The range of the Rayleigh (Ra) number was explored from 103 to 106 for a Newtonian fluid of Prandtl number equal to 1.0. The dimensionless amplitude (h/H) of roughness elements was fixed to 0.1, while the spacing between these elements was equal to twice their height. The maximum reduction in the average heat transfer was calculated to be 27 percent at Ra number 1×106.

HVAC Blower Aeroacoustics Predictions Based on the Lattice Boltzmann Method

2011 ◽  
Author(s):  
Franck Pe´rot ◽  
Min-Suk Kim ◽  
Koichi Wada ◽  
Koji Norisada ◽  
Motohiro Kitada ◽  
...  
Keyword(s):  
Lattice Boltzmann Method ◽  
Lattice Boltzmann ◽  
Standard Procedure ◽  
Pressure Rise ◽  
Operating Conditions ◽  
Acoustic Measurements ◽  
Noise Sources ◽  
Flow Information ◽  
Flow Induced Noise ◽  
Boltzmann Method

Two centrifugal HVAC fan and casing geometries are experimentally and numerically investigated. Aerodynamic and acoustic measurements are performed at three operating conditions following an ISO standard procedure. Explicit and compressible CFD/CAA simulations based on the Lattice Boltzmann Method are performed for six configurations. From these simulations, flow information in term of pressure rise as a function of the mass flow rate and noise are obtained at the same time and compared to experiments. Additional post-processing is performed to have an insight on the origin and location of flow-induced noise sources.

Numerical Simulation of Droplet Flows and Evaluation of Interfacial Area

2002 ◽  
Vol 124 (3) ◽  
pp. 576-583 ◽  
Author(s):  
T. Watanabe ◽  
K. Ebihara
Keyword(s):  
Lattice Boltzmann ◽  
Weber Number ◽  
Volume Fraction ◽  
Interfacial Area ◽  
Force Balance ◽  
Two Phase ◽  
Critical Weber Number ◽  
Boltzmann Method ◽  
Droplet Flows ◽  
Good Agreement

Droplet flows with coalescence and breakup are simulated numerically using the lattice Boltzmann method. It is shown that the rising velocities are in good agreement with those obtained by the force balance and the empirical correlation. The breakup of droplets after coalescence is simulated well in terms of the critical Weber number. A numerical method to evaluate the interfacial area and the volume fraction in two-phase flows is proposed. It is shown that the interfacial area corresponds to the shape, the number and the size of droplets, and the proposed method is effective for numerical evaluation of interfacial area even if the interface changes dynamically.

Incorporating Turbulence Models into the Lattice-Boltzmann Method

1998 ◽  
Vol 09 (08) ◽  
pp. 1159-1175 ◽  
Author(s):  
Christopher M. Teixeira
Keyword(s):  
Lattice Boltzmann Method ◽  
Turbulent Flows ◽  
Lattice Boltzmann ◽  
Turbulence Models ◽  
Algebraic Model ◽  
Expansion Ratio ◽  
Equation Model ◽  
Recirculation Length ◽  
Boltzmann Method ◽  
Good Agreement

The Lattice-Boltzmann method (LBM) is extended to allow incorporation of traditional turbulence models. Implementation of a two-layer mixing-length algebraic model and two versions of the k-ε two-equation model, Standard and RNG, in conjunction with a wall model, are presented. Validation studies are done for turbulent flows in a straight pipe at three Re numbers and over a backwards facing step of expansion ratio 1.5 and Re H=44 000. All models produce good agreement with experiment for the straight pipes but the RNG k-ε model is best able to capture both the recirculation length, within 2% of experiment, and the detailed structure of the mean fluid flow for the backwards facing step.

scholarly journals An extensible lattice Boltzmann method for viscoelastic flows: complex and moving boundaries in Oldroyd-B fluids

2021 ◽  
Vol 44 (1) ◽  
Author(s):  
Michael Kuron ◽  
Cameron Stewart ◽  
Joost de Graaf ◽  
Christian Holm
Keyword(s):  
Lattice Boltzmann ◽  
Computational Models ◽  
Moving Boundary ◽  
Biological Fluids ◽  
Colloidal Suspensions ◽  
Viscoelastic Flows ◽  
Complex Flow ◽  
Complex Boundaries ◽  
Boltzmann Method ◽  
Good Agreement

Abstract  Most biological fluids are viscoelastic, meaning that they have elastic properties in addition to the dissipative properties found in Newtonian fluids. Computational models can help us understand viscoelastic flow, but are often limited in how they deal with complex flow geometries and suspended particles. Here, we present a lattice Boltzmann solver for Oldroyd-B fluids that can handle arbitrarily shaped fixed and moving boundary conditions, which makes it ideally suited for the simulation of confined colloidal suspensions. We validate our method using several standard rheological setups and additionally study a single sedimenting colloid, also finding good agreement with the literature. Our approach can readily be extended to constitutive equations other than Oldroyd-B. This flexibility and the handling of complex boundaries hold promise for the study of microswimmers in viscoelastic fluids. Graphic abstract

Sign in / Sign up

Export Citation Format

Share Document