Cfd Final Submission Draft

8/3/2019 Cfd Final Submission Draft

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FLOW OVER A FLAT PLATE

Analyze a fluid flow over a flat plate flowing with a velocity of 1 m/s the free air stream temperature of

the flow is 353 K.

INITIAL ASSUMPTIONS:

The assumption of incompressible flow becomes invalid increasingly less valid for larger temperature

differences between the plate and free stream. Because of this, we will treat this as a compressible flow.

We will analyze a fluid flow with the following non-dimensional conditions:

In order to achieve these flow conditions, we will use these free stream flow conditions:

According to the ideal gas law, this temperature and pressure result in the following freestream density:


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BOUNDRAY CONDITIONS:

1. INLET TYPE: Velocity inlet

2. VELOCITY: 1 m/s

3. FREE STREAM TEMPERATURE: 353K4. TURBULENCE INTENSITY: 1

5. TURBULENCE VISCOSITY RATIO: 1

6. OUTLET TYPE: Pressure outlet

7. WALL TEMPERATURE: 413K

8. TOP OF FLOW: Symmetry

PROCEDURE:

1.

Create the geometry profile using GAMBIT

2. After geometry profile is created the geometry profile is meshed using GAMBITS inbuilt mesh

tool

3. After the meshing is successfully completed the mesh file has to be exported and saved in your

working directory.

4. Now the problem is set up in fluent software.

5. The exported mesh file is imported in the fluent software.

6. Boundary conditions are to be defined now.

7. SOLVE

8. Change Density, Momentum, Turbulence Kinetic Energy, Turbulence Dissipation Rate, and

Energy all to Second Order Upwind. Leave Pressure and Pressure-Velocity Coupling set to thedefault methods (Standard and SIMPLE, respectively)

9. Set Initial Guess: In the Solution Initialization window that comes up, choose inflow under

Compute From. The X Velocity for allcells will automatically be set to 1 m/s, the Y Velocity to 0

m/s and the Gauge Pressure to 0 Pa. These values have been taken from the inflow boundary

condition.

10.Set Convergence Criteria: FLUENT reports a residual for each governing equation being solved.

The residual is a measure of how well the current solution satisfies the discrete form of each

governing equation. We will iterate until the residual for each equation falls below 1e-6. Change

the residual under Convergence Criterion for continuity, x-velocity, and y-velocity, energy, k, and

epsilon all to 1e-6.11.Set no of iterations to 10000 and iterate until solution converges. If it doesnt converges within

10000 iterations keep on icreasing no of iterations in steps of 100 until solution converges.

12.Analyze the data.


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OBSERVATIONS:

POSITION HEAT FLUHEATFLUX*POSITION TEMP REYNOLDS NO NUSSELT NO VEL

0.02 327.292 6.54584 398.366 9818760 115.4408056 0.2

0.05 215.047 10.75235 401.682 16128525 189.6257694 0.2

0.083333 197.846 16.48716007 402.64 24730740.11 290.7634529 0.1

0.116667 186.708 21.78266224 403.248 32673993.35 384.1536116 0.1

0.15 177.843 26.67645 403.655 40014675 470.459235 0.1

0.183333 170.296 31.22087657 403.992 46831314.85 550.6036112 0.1

0.216667 163.731 35.47510458 404.291 53212656.87 625.6301179 0.1

0.25 157.974 39.4935 404.537 59240250 696.4975398 0.1

0.283333 152.898 43.32104903 404.741 64981573.55 763.9992423 0

0.316667 148.405 46.99496614 404.921 70492449.2 828.7915302 0.1

0.35 144.411 50.54385 405.091 75815775 891.378763 0.1

0.383333 140.847 53.99130305 405.251 80986954.58 952.1771873 0.1

0.416667 137.656 57.35671255 405.397 86035068.83 1011.528712 0.1

0.45 134.789 60.65505 405.527 90982575 1069.697371 0.1

0.483333 132.205 63.89903927 405.644 95848558.9 1126.907558 0.1

0.516667 129.868 67.09850996 405.752 100647764.9 1183.332627 0.1

0.55 127.747 70.26085 405.854 105391275 1239.102869 0.1

0.583333 125.817 73.39320806 405.951 110089812.1 1294.344357 0.1

0.616667 124.055 76.50062469 406.046 114750937 1349.145983 0.1

0.65 122.441 79.58665 406.135 119379975 1403.570358 0.1

0.683333 120.958 82.65459301 406.219 123981889.5 1457.675838 0.1

0.716667 119.591 85.7069232 406.297 128560384.8 1511.505973 0.1

0.75 118.329 88.74675 406.37 133120125 1565.115602 0.

0.783333 117.158 91.77372761 406.438 137660591.4 1618.498626 0.1

0.816667 116.07 94.79053869 406.502 142185808 1671.702356 0.1

0.85 115.057 97.79845 406.563 146697675 1724.749131 0.1

0.883333 114.112 100.7988953 406.62 151198342.9 1777.664238 0.1

0.916667 113.231 103.7951211 406.675 155692681.6 1830.504931 0.1

0.95 112.402 106.7819 406.722 160172850 1883.179021 0.1


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MESH:

PLOTS:

0

50100

150

200

250

300

350

0 10 20 30 40

TEMP

POSITION

TEMP DISTRIBUITION


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0

500

10001500

2000

0 100000000 200000000nusseltnumber

reynold`s number

Nu v/s Re

NUSSE

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

0 10 20 30 40

WallYplus

position

wall Yplus

0

0.2

0.4

0.6

0.8

1

1.2

0 20 40 60 80 100 120

V

elocity

Position

VELOCITY PROFILE


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FLOW THROUGH A PIPE

Analyze a fluid flow through a circular pipe flowing with a velocity of 5 m/s the free air stream

temperature of the flow is 274 K. Heat flux through wall is 5W/cm2 and length of pipe is 150m anddiameter is 1m

PRELIMINARY ANALYSIS:

We expect the viscous boundary layer to grow along the pipe starting at the inlet. It will eventually grow

to fill the pipe completely (provided that the pipe is long enough). When this happens, the flow becomes

fully-developed and there is no variation of the velocity profile in the axial direction,x

For calculating Nusselt Number:

N=

Where

Qw = Heat flux through wall

L= length of pipe

Tw = Wall Temp

Tm=Bulk Mean Temp

K=Thermal Conductivity Of fluid


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BOUNDRAY CONDITIONS:

9. INLET TYPE: Velocity inlet

10.VELOCITY: 5 m/s

11.FREE STREAM TEMPERATURE: 274K12.TURBULENCE INTENSITY: 1

13.TURBULENCE VISCOSITY RATIO: 1

14.OUTLET TYPE: Pressure outlet maintained at atmospheric pressure

15.HEAT FLUX THROUGH WALL: 5W/m2

16.TOP OF FLOW: Symmetry

PROCEDURE:

13.Create the geometry profile using GAMBIT

14.After geometry profile is created the geometry profile is meshed using GAMBITS inbuilt mesh

tool

15.After the meshing is successfully completed the mesh file has to be exported and saved in your

working directory.

16.Now the problem is set up in fluent software.

17.The exported mesh file is imported in the fluent software.

18.Boundary conditions are to be defined now.

19.SOLVE

20.Change Density, Momentum, Turbulence Kinetic Energy, Turbulence Dissipation Rate, and

Energy all to Second Order Upwind. Leave Pressure and Pressure-Velocity Coupling set to thedefault methods (Standard and SIMPLE, respectively)

21.Set Initial Guess: In the Solution Initialization window that comes up, choose inflow under

Compute From. The X Velocity for allcells will automatically be set to 5 m/s, the Y Velocity to 0

m/s and the Gauge Pressure to 0 Pa. These values have been taken from the inflow boundary

condition.

22.Set Convergence Criteria: FLUENT reports a residual for each governing equation being solved.

The residual is a measure of how well the current solution satisfies the discrete form of each

governing equation. We will iterate until the residual for each equation falls below 1e-10.

Change the residual under Convergence Criterion for continuity, x-velocity, and y-velocity,

energy, k, and epsilon all to 1e-10.23.Set no of iterations to 10000 and iterate until solution converges. If it doesnt converges within

10000 iterations keep on increasing no of iterations in steps of 100 until solution converges.

24.Analyze the data.


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OBSERVATIONS:

Position WALL TEMP(Tw) BULK MEAN TEMP Tm K q'' Nu

10 278.423 274.063 0.02 4 45.871

20 280.266 274.125 0.02 4 32.567

30 281.595 274.186 0.02 4 26.994

40 282.737 274.248 0.02 4 23.55

50 283.749 274.312 0.02 4 21.193

60 284.616 274.373 0.02 4 19.525

70 285.389 274.433 0.02 4 18.254

80 286.122 274.494 0.02 4 17.199

90 286.811 274.556 0.02 4 16.319

0

5

10

15

20

25

30

35

40

0 20 40 60 80 100 120

Nu

Position

Nu Vs. Position Chart

Nu


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LAMINAR FLOW THROUGH PIPE


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FORRCED CONVECTION OVER A PLATE:


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TURBULENT FLOW THROUGH PIPE:


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SUPERSONIC FLOW OVER A WEDGE:


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FLOW THROUGH NOZZLE:


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FLOW OVER AN AIRFOIL:


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Cfd Final Submission Draft

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