Numerical Study on Deformation Behavior of a Fluid Particle Under Shear Flow

2011 ◽  
Author(s):  
Youngho Suh ◽  
Changhoon Lee
Keyword(s):  
Shear Flow ◽  
Deformation Behavior ◽  
Present Method ◽  
Numerical Study ◽  
Three Dimensional ◽  
Flow Conditions ◽  
Droplet Deformation ◽  
Lift Forces ◽  
Drag And Lift ◽  
Acting Force

In this work, we studied the deformation behavior of a droplet under the various flow conditions. The droplet deformation is calculated by a level-set method. In order to determine the acting force on a particle in shear flow field, we propose the feedback forces which can maintain particle position with efficient handling of deformation. Computations were carried out to investigate the deformation behavior of a droplet caused by the surrounding gaseous flow and the effect of the deformation on the droplet characteristics with various dimensionless parameters. Based on the numerical results, we observed that drag and lift forces acting on a droplet depend strongly on the deformation. Also, the present method is proven to be applicable to a three-dimensional deformation of droplet in shear flow, which cannot be properly analyzed by the previous studies. The drag and lift forces obtained from the present numerical method are favorably compared with the data reported in the literature.

Numerical Investigation of the Drag and Lift Forces Acting on Impenetrable Rotating Spherical Nano-Particle

2008 ◽  
Author(s):  
M. R. Meigounpoory ◽  
A. Rahi ◽  
A. Mirbozorgi
Keyword(s):  
Lift Coefficient ◽  
Three Dimensional ◽  
Slip Boundary Condition ◽  
Slip Condition ◽  
Nano Particle ◽  
Slip Coefficient ◽  
Slip Boundary ◽  
Lift Forces ◽  
Drag And Lift ◽  
Drag And Lift Coefficient

The drag and lift forces acting on a rotating impenetrable spherical suspended nano-particle in a homogeneous uniform flow are numerically studied by means of a three-dimensional numerical simulation with slip boundary condition. The effects of both the slip coefficient and rotational speed of the nanosphere on the drag and lift forces are investigated for Reynolds numbers in the range of 0.1 < Re < 100. Increase of rotation increases the drag and lift force exerted by flow at the surface of nano-sphere. By increasing slip coefficient the values of drag and lift coefficients decreases. At full slip condition, rotation of the nano-sphere has not significant effects on the drag and lift coefficient values moreover the lift coefficient of flow around the rotating spherical particle will be vanished. Present numerical results at no-slip condition are in good agreements with certain results of flow around of rotating sphere.

Drag and Lift Forces Acting on a Sphere in Shear Flow of Power-Law Fluid

2018 ◽  
Vol 27 (4) ◽  
pp. 474-488 ◽  
Author(s):  
A. A. Gavrilov ◽  
K. A. Finnikov ◽  
Ya. S. Ignatenko ◽  
O. B. Bocharov ◽  
R. May
Keyword(s):  
Shear Flow ◽  
Power Law ◽  
Power Law Fluid ◽  
Lift Forces ◽  
Drag And Lift

On Flowfield Periodicity in the NASA Transonic Flutter Cascade: Part II — Numerical Study

2000 ◽  
Author(s):  
R. V. Chima ◽  
E. R. McFarland ◽  
J. R. Wood ◽  
J. Lepicovsky
Keyword(s):  
Static Pressure ◽  
Numerical Study ◽  
Three Dimensional ◽  
Side Wall ◽  
Wave Structure ◽  
Experimental Measurements ◽  
Flow Conditions ◽  
Pressure Sensitive ◽  
Transonic Flutter ◽  
Probe Measurements

The transonic flutter cascade facility at NASA Glenn Research Center was redesigned based on a combined program of experimental measurements and numerical analyses. The objectives of the redesign were to improve the periodicity of the cascade in steady operation, and to better quantify the inlet and exit flow conditions needed for CFD predictions. Part I of this paper describes the experimental measurements, which included static pressure measurements on the blade and endwalls made using both static taps and pressure sensitive paints, cobra probe measurements of the endwall boundary layers and blade wakes, and shadowgraphs of the wave structure. Part II of this paper describes three CFD codes used to analyze the facility, including a multibody panel code, a quasi-three-dimensional viscous code, and a fully three-dimensional viscous code. The measurements and analyses both showed that the operation of the cascade was heavily dependent on the configuration of the sidewalls. Four configurations of the sidewalls were studied and the results are described. For the final configuration, the quasi-three-dimensional viscous code was used to predict the location of mid-passage streamlines for a perfectly periodic cascade. By arranging the tunnel sidewalls to approximate these streamlines, side-wall interference was minimized and excellent periodicity was obtained.

Numerical study of obstacle geometry effect on the vortex shedding suppression and aerodynamic characteristics

2019 ◽  
Vol 30 (2) ◽  
pp. 469-495 ◽  
Author(s):  
Salwa Fezai ◽  
Nader Ben-Cheikh ◽  
Brahim Ben-Beya ◽  
Taieb Lili
Keyword(s):  
Vortex Shedding ◽  
Stokes Equations ◽  
Numerical Study ◽  
Time Derivative ◽  
Content Type ◽  
Rectangular Shape ◽  
Lift Forces ◽  
Drag And Lift ◽  
Obstacle Geometry ◽  
Unsteady Regimes

Purpose Two-dimensional incompressible fluid flows around a rectangular shape placed over a larger rectangular shape at low Reynolds numbers (Re) have been numerically analyzed in the present work. The vortex shedding is investigated at different arrangements of the two shapes allowing the investigation of three possible configurations. The calculations are carried out for several values of Re ranging from 1 to 200. The effect of the obstacle geometry on the vortex shedding is analyzed for crawling, steady and unsteady regimes. The analysis of the flow evolution shows that with increasing Re beyond a certain critical value, the flow becomes unstable and undergoes a bifurcation. This paper aims to observe that the transition of the unsteady regime is performed by a Hopf bifurcation. The critical Re beyond which the flow becomes unsteady is determined for each configuration. A special attention is paid to compute the drag and lift forces acting on the rectangular shapes, which allowed determining; the best configuration in terms of both drag and lift. The unsteady periodic wake is characterized by the Strouhal number, which varies with the Re and the obstacle geometry. Hence, the values of vortex shedding frequencies are calculated in this work. Design/methodology/approach The dimensionless Navier–Stokes equations were numerically solved using the following numerical technique based on the finite volume method. The temporal discretization of the time derivative is performed by an Euler backward second-order implicit scheme. Non-linear terms are evaluated explicitly; while, viscous terms are treated implicitly. The strong velocity–pressure coupling present in the continuity and the momentum equations are handled by implementing the projection method. Findings The present paper aims to numerically study the effect of the obstacle geometry on the vortex shedding and on the drag and lift forces to analyze the flow structure around three configurations at crawling, steady and unsteady regimes. Originality/value A special attention is paid to compute the drag and lift forces acting on the rectangular shapes, which allowed determining; the best shapes configuration in terms of both drag and lift.

scholarly journals Numerical study of droplet deformation in shear flow using a conservative level-set method

2019 ◽  
Vol 207 ◽  
pp. 153-171 ◽  
Author(s):  
Ahmad Amani ◽  
Néstor Balcázar ◽  
Jesús Castro ◽  
Assensi Oliva
Keyword(s):  
Shear Flow ◽  
Level Set Method ◽  
Level Set ◽  
Numerical Study ◽  
Droplet Deformation ◽  
Conservative Level Set

Numerical Study of the Heat Transfer Rate in a Helical Static Mixer

2006 ◽  
Vol 128 (8) ◽  
pp. 769-783 ◽  
Author(s):  
Ramin K. Rahmani ◽  
Theo G. Keith ◽  
Anahita Ayasoufi
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Heat Transfer Rate ◽  
Transfer Rate ◽  
Numerical Study ◽  
Three Dimensional ◽  
Static Mixer ◽  
Flow Conditions ◽  
Modern Approach ◽  
Static Mixers

In chemical processing industries, heating, cooling, and other thermal processing of viscous fluids are an integral part of the unit operations. Static mixers are often used in continuous mixing, heat transfer, and chemical reactions applications. In spite of widespread usage, the flow physics of static mixers is not fully understood. For a given application, besides experimentation, the modern approach to resolve this is to use powerful computational fluid dynamics tools to study static mixer performance. This paper extends a previous study by the authors on an industrial helical static mixer and investigates heat transfer and mixing mechanisms within a helical static mixer. A three-dimensional finite volume simulation is used to study the performance of the mixer under both laminar and turbulent flow conditions. The turbulent flow cases were solved using k−ω model. The effects of different flow conditions on the performance of the mixer are studied. Also, the effects of different thermal boundary conditions on the heat transfer rate in static mixer are studied. Heat transfer rates for a flow in a pipe containing no mixer are compared to that with a helical static mixer.

Sign in / Sign up

Export Citation Format

Share Document