Icmens 2009 L100
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Presentation made on Simulations conducted for a microfluidic mixer at the 5th International Conference for MEMS, NANO and Smart Systems 2009, held at Dubai, UAE.
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The document discusses velocity distribution in diverging channels. It summarizes previous research on modeling flow in non-prismatic channels and the effects of roughness. The author then describes their study simulating flow in a diverging channel with smooth and gravel beds using ANSYS. The simulation results matched experimental data well. Velocity was found to decrease with increasing diverging angle and distance from the channel centerline.
A Computational Analysis of Flow StructureThrough Constant Area S-Duct
This paper presents the results of an experimental work with measurement of mean velocity contours in 2-D form and validation of the same with numerical results based on the y+ approach at fully developed flow for various turbulent models like, k-ε model, k-ω model, RNG k-ε model and Reynolds Stress Model (RSM), are used to solve the problem. All the turbulence models are studied in the commercial CFD code of Fluent. The experiment is carried out at mass averaged mean velocity of 40m/s and the geometry of the duct is chosen as rectangular cross-section of 45°/45° curved constant area S-duct. In the present paper the computational results obtained from the different turbulence models are compared with the experimental results. In addition to this for validation of the numerical simulation near wall treatments for fully developed flow or log-law region are also investigated for wall 30<y+><300 in the region where turbulent shear dominates. It is concluded from the present study that the mesh resolving the fully turbulent region is sufficiently accurate in terms of qualitative features. Here RSM turbulence model predicts the best results while comparing with the experimental results.RSM model also predicts the flow properties more consistently because it accounts for grid independence test.
CFD simulation of Lid driven cavity flow
This project aims at simulating lid driven cavity flow problem using package MATLAB. Steady Incompressible Navier-Stokes equation with continuity equation will be studied at various Reynolds number. The main aim is to obtain the velocity field in steady state using the finite difference formulation on momentum equations and continuity equation. Reynold number is the pertinent parameter of the present study. Taylor’s series expansion has been used to convert the governing equations in the algebraic form using finite difference schemes.
A Computational Analysis of Flow Development through a Constant Area C- Duct
1. The document presents a computational analysis and experimental validation of flow through a constant area C-duct with a 90 degree curved section.
2. Experiments were conducted on a rectangular C-duct cross-section to measure mean velocity and total pressure. Computational fluid dynamics simulations using various turbulence models were performed and compared to experimental results.
3. The RSM turbulence model showed the best agreement with experimental measurements of mean velocity contours at the duct outlet, accurately predicting the shift of bulk velocity toward the outer wall due to secondary flow effects.
Final-Thesis-present.pptx
Two-layer 2D model for hydrodynamics and solute transport was developed and tested for lab. data. Model was working satisfactorily.
report
This project simulated the flow of granular particles down an inclined plane using molecular dynamics simulation software. Simulations were run for a range of inclination angles and system sizes. Results showed the kinetic energy, velocity, and packing fraction profiles agreed with previous research. Some limitations were encountered with system size, particle properties, and boundary conditions that require further investigation. The consistency with previous work validates the simulation model, while deviations at certain angles point to needs for improved understanding.
Numerical Analysis of MHD Flow of Fluid with One Porous Bounding Wall
1. The document analyzes the laminar flow of a viscous, incompressible fluid between two parallel plates, where one plate is porous and the other is rigid.
2. It develops governing equations for the fluid flow using the Navier-Stokes equations and introduces dimensionless variables and a perturbation method.
3. It presents results showing that increasing the magnetic field increases the fluid velocity, while increasing the channel height decreases the velocity at a constant Reynolds number and slip coefficient. Graphs demonstrate how the fluid velocity profiles vary with changing magnetic field.
Af03101880194
This document summarizes a numerical simulation study of flow past a circular cylinder in a channel at varying ratios of tunnel height to cylinder diameter (H/D). Two computational fluid dynamics codes, 3D PURLES and OpenFOAM, were used to simulate the flow at a Reynolds number of 40. The simulations showed a decrease in wake length and a shift of flow separation downstream at smaller H/D ratios. Grid resolution and H/D ratios from 2-30 were investigated. The results from both codes were consistent and confirmed the effects of tunnel walls in changing flow characteristics around the cylinder.
A Computational Investigation of Flow Structure Within a Sinuous Duct
In the present investigation the distribution of mean velocity are experimentally studied on three constant area
rectangular curved ducts with an aspect ratio of 2.4. First one is C-shape, second one is S-shape and third one
is a DS-shape duct. The experiment is carried out at mass averaged mean velocity of 40m/s for all the ducts.
The velocity distribution shows for C-duct, the bulk flow shifting from outer wall to the inner wall along the
flow passage and for S-duct, the bulk flow shifting from outer wall to the inner wall in the first half and from
inner wall to the outer wall in the second half along the flow passage of curved ducts are very instinct. Due to
the imbalance of centrifugal force and radial pressure gradient, secondary motions in the forms of counter
rotating vortices have been generated within both the curved duct. For DS-duct the velocity distributions shows
the Bulk of flow shifting from inner watt to outer wall in the first bend and third bend of the duct and outer wall
to inner wall in the second bend and forth bend of the duct along the flow passage is very instinct. Flow at end
of the DS-duct is purely uniform in nature due to non existence of secondary motion. The experimental results
then were numerically validated with the help of Fluent, which shows a good agreement between the
experimental and predicted results for all the ducts
TRANSIENT ANALYSIS OF PIEZOLAMINATED COMPOSITE PLATES USING HSDT
Piezoelectric materials have excellent sensing and actuating capabilities have made them the most practical smart materials to integrate with laminated structures. Integrated structure system can be called a smart structure because of its ability to perform self-diagnosis and quick adaption to environment changes. An analytical procedure has been developed in the work based on higher order shear deformation theory subjected to electromechanical loading for investigating transient characteristics of smart material plates. For analysis two displacement models are to be considered i.e., model-1 accounts for strain in thickness direction is zero whereas in model-2 in-plane displacements are expanded as cubic functions of the thickness coordinate. Navier’s technique has been adopted for obtaining solutions of anti-symmetric cross–ply and angle-ply laminates of both model-1 and model-2 with simply supported boundary conditions. For obtaining transient response of a laminated composite plate attached with piezoelectric layer Newmark’s method has been used. Effect of thickness coordinate of composite laminated plates attached with piezoelectric layer subjected to electromechanical loadings is studied.
THE EFFECTS OF UNIFORM TRANSVERSE MAGNETIC FIELD ON LOCAL FLOW AND VELOCITY P...
A numerical model studied the effects of uniform transverse magnetic field for two fluids (pure water and water with electric conductivity), two different non-magnetizable duct and two flow velocities (steady flow for laminar and incompressible) was examined and The results showed an increase in the magnetic field caused a decrease in the local flow and effected on velocity profile. The result also showed that the water with electrical conductivity more affected than pure water.
LATTICE BOLTZMANN SIMULATION OF NON-NEWTONIAN FLUID FLOW IN A LID DRIVEN CAVITY
Lattice Boltzmann Method (LBM) is used to simulate the lid driven cavity flow to explore the mechanism of non-Newtonian fluid flow. The power law model is used to represent the class of non-Newtonian fluids (shear-thinning and shear-thickening fluids) by considering a range of 0.8 to 1.6. Investigation is carried out to study the influence of power law index and Reynolds number on the variation of velocity profiles and streamlines plots. Velocity profiles and the streamline patterns
for various values of power law index at Reynolds numbers ranging 100 to 3200 are presented. Half way bounce back boundary conditions are employed in the numerical method.
Fm ppt unit 4
This document is a lecture on fluid mechanics covering topics such as laminar flow through pipes, Stoke's law, the transition from laminar to turbulent flow, types of turbulent flow including wall turbulent shear flow and isotropic turbulence, the eddy viscosity hypothesis, turbulent flow in smooth and rough pipes, minor losses in pipes, pipes arranged in series and parallel, siphons, and water hammer. It was authored by Mr. Md Ateeque Khan, an assistant professor in the Department of Mechanical Engineering at Jahangirabad Institute of Technology, Barabanki for the subject of fluid mechanics.
Lattice boltzmann simulation of non newtonian fluid flow in a lid driven cavit
This document summarizes a study that uses Lattice Boltzmann Method (LBM) to simulate non-Newtonian fluid flow in a lid driven cavity. The study explores the mechanism of non-Newtonian fluid flow using the power law model to represent shear-thinning and shear-thickening fluids. It investigates the influence of power law index and Reynolds number on velocity profiles and streamlines. The LBM code is validated against published results and shows agreement with established theory and fluid rheological behavior.
A Criterial Assessment of Quality Transformations a Plane Elastic Wave in the...
A Criterial Assessment of Quality Transformations a Plane Elastic Wave in the...International Journal of Engineering Inventions www.ijeijournal.com
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The document summarizes an experimental study on the effect of aspect ratio on the near-field dynamics of submerged rectangular turbulent jets interacting with a free surface. Planar particle image velocimetry was used to measure the velocity fields of jets with aspect ratios of 1, 2, and 4 at a fixed offset from the free surface. The study found that higher aspect ratio jets evolved more quickly into free surface jets, with the aspect ratio 2 jet exhibiting the fastest centerline velocity decay. Turbulence intensities were highest for the aspect ratio 2 jet in the near-field but decreased below the aspect ratio 4 jet in the far-field. The impingement point where the jet attached to the free surface occurred between 8-12
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Icmens 2009 L100
- 1. Nayaz Khalid Ahmed and Martin Hecht National Institute of Technology, Tiruchirappalli, INDIA – 620 015 Institute for Computational Physics, Pfaffenwaldring 27, 70569 Stuttgart, GERMANY A lattice Boltzmann study of flow along patterned surfaces and through channels with alternating slip length
- 3. Slip Flows
- 6. Slip Flows Presence of slip during interaction between solid and fluid interface General assumption of no-slip condition in macro flows fails in micro fluidics λ – slip length
- 7. Lattice Boltzmann Method (LBM) At the microscopic level – Velocity distribution of particles, Brownian motion, huge number of particles/degree of freedom Describe motion of particles by distribution functions –
- 8. Lattice Boltzmann Method (LBM) Boltzmann’s equation – time evolution of the distribution functions
- 13. y , z direction – periodic boundaries
- 14. x direction – slip flow with stripes
- 16. Continuously varying striped walls Slip parameter varies as a continuous periodic function along the wall: where the wave vector k defines the frequency and direction of the variation of slip parameter ζ. Amplitude and mean ζ = 0.5 and wave vector points in the diagonal direction Velocity along the x boundary wall. (Colour coding: y component)
- 17. Continuously varying striped walls Fluid arriving is a region of smaller slip has to go aside: - Vortice in the plane perpendicular to the direction of accelerating force occurs. Averaged projection of velocity vectors on the xy plane. Homogeneous rotation about the centre is observed. Velocity at the centre is aligned with the channel. Curl of the z-component velocity field, averaged along the z-direction. Homogeneous rotation is more clearly observed.
- 18. Conclusion Study confirms tensorial nature of slip proposed by M.Z. Bazant and O.I. Vinogradova, Journal of Fluid Mechanics, 613, 125-134, 2008. Generation of vortex – surface wall pattern can be exploited for designing Micro mixer devices. Heartfelt thanks to the DAAD for the WISE 2009 Scholarship to carry out my work. We also wish to thank the German Research Foundation (DFG) for financial support within grant EAMatWerk. Thank YOU