FLOW PAST A SPHERE

M.D.Subramanyam(134107004)

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CONTENTS Types of fluids Project statement Literature survey Fluid flow Parameters Blunt & Streamlined bodies(applications)

Flow past cylinder Results, problems, future work

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TYPES OF FLUIDS

Newtonian fluid

Non-Newtonian fluids1. Bingham plastic2. Pseudo plastic 3. Dilatant

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PROJECT STATEMENT

To know the range of Re where flow symmetry sustains.

To evaluate the values of Cp around the sphere.

Velocity stream lines past sphere

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LITERATURE SURVEY Flow field pressure coefficient contours for axis symmetrical flow

vorticity contours flow past a sphere Stream line pattern at respective reynolds number

Comsol tutorials

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FLOW PARAMETERS Drag coefficient Components of drag coefficient Surface pressure coefficient Surface vorticity Separation angle Recirculation length

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BLUNT & STREAMLINED BODIES A body moving through a fluid experiences a drag force, which is divided into 2 components:

1.frictional drag 2.pressure drag Streamlined body : more viscous drag Bluff body : more pressure drag

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APPLICATIONS Drag coefficients are used in calculation of particle terminal settling velocity of solids

Tall Chimneys constructed of thin walled steel tube to prevent vortex shedding.

Overhead powerline wires Swimming Magnus effect and many….

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Dimples on golf ball creates rough surface, thus reducing the drag and moves farther with out losing momentum

Daily life example

FLOW PAST A CYLINDERThe nature of the flow across a cylinder strongly affects drag coefficient. Both frictional drag and pressure drag can be significant. The high pressure in the vicinity of stagnation point and the low pressure on the opposite point in the wake produce a net force on the body in the direction of flow.

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CONCLUSION Results1. Drag coefficient for Re=100 is 1.092. Drag coefficient for Re=200 is 0.793. Correct pressure distribution curve around sphere.

Facing problems1. The values of surface pressure coefficient and surface vorticity for respective reynolds number2. Getting accustomed to language of comsol Future work upgradation of bio-oil using Dehydrooxidation process in ebulated fluid bed reactor

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0.00 90.00 180.00 270.00 360.00

-1

-0.5

0

0.5

1

1.5

cp

REFERENCES Flow of power-law fluids past a sphere at Intermediate Reynolds number – sunil.D.Dhole,Raj.P.Chhabra,Vinayak Eswaran

A numerical study of the unsteady wake behind a sphere in a uniform flow at moderate Reynolds numbers - Sungsu lee

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SINCERE GRATITUDE TO MY SUPERVISOR

Dr.Nanda kishore

thanks to all

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