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Problem Specification
1. Create Geometry in GAMBIT
2. Mesh Geometry in GAMBIT
3. Specify Boundary Types in GAMBIT
4. Set Up Problem in FLUENT
5. Solve!
6. Analyze Results
7. Refine Mesh
Problem 1
Problem 2

{panel}
[Problem Specification|FLUENT - Steady Flow Past a Cylinder - Problem Specification]\\
[1. Create Geometry in GAMBIT|FLUENT - Steady Flow Past a Cylinder - Step 1]\\
[2. Mesh Geometry in GAMBIT|FLUENT - Steady Flow Past a Cylinder - Step 2]\\
[3. Specify Boundary Types in GAMBIT|FLUENT - Steady Flow Past a Cylinder - Step 3]\\
[4. Set Up Problem in FLUENT|FLUENT - Steady Flow Past a Cylinder - Step 4]\\  {color:#ff0000}{*}5. Solve\!*{color}\\
[6. Analyze Results|FLUENT - Steady Flow Past a Cylinder - Step 6]\\
[7. Refine Mesh|FLUENT - Steady Flow Past a Cylinder - Step 7]\\
[Problem 1|FLUENT - Steady Flow Past a Cylinder - Problem 1]\\
[Problem 2|FLUENT - Steady Flow Past a Cylinder - Problem 2]
{panel}

h2. Step 5: Solve\!

We'll use a second-order discretization scheme.

*Main Menu > Solve > Controls > Solution...*

Change {color:#660099}{*}{_}Momentum{_}{*}{color} to {color:#660099}{*}{_}Second          Order Upwind{_}{*}{color}.

!step5_img001.jpg!
Click {color:#660099}{*}{_}OK{_}{*}{color}.

h4. Set Initial Guess

Initialize the flow field to the values at the inlet:

*Main Menu > Solve > Initialize > Initialize...*

In the _Solution Initialization_ menu that comes up, choose {color:#660099}{*}{_}inlet{_}{*}{color} under {color:#660099}{*}{_}Compute From{_}{*}{color}. The {color:#660099}{*}{_}X          Velocity{_}{*}{color} for _all_ cells will be set to 1 m/s, the {color:#660099}{*}{_}Y{_}{*}{color} {color:#660099}{*}{_}Velocity{_}{*}{color} to 0 m/s and the {color:#660099}{*}{_}Gauge Pressure{_}{*}{color} to 0 Pa. These values have been taken from the inlet boundary condition.

!step5_img002.jpg!

Click {color:#660099}{*}{_}Init{_}{*}{color}. This completes the initialization. {color:#660099}{*}{_}Close{_}{*}{color} the window.

h4. 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'll iterate the solution until the          residual for each equation falls below 1e-6.

*Main Menu > Solve > Monitors > Residual...*

Change the residual under {color:#660099}{*}{_}Convergence Criterion{_}{*}{color} for {color:#660099}{*}{_}continuity{_}{*}{color}, {color:#660099}{*}{_}x-velocity{_}{*}{color},          and {color:#660099}{*}{_}y-velocity{_}{*}{color}, all to 1e-5.

Also, under {color:#660099}{*}{_}Options{_}{*}{color}, select {color:#660099}{*}{_}Plot{_}{*}{color}. This will plot the residuals in the graphics window as they are          calculated.

 !step5_img003.jpg!
Click {color:#660099}{*}{_}OK{_}{*}{color}.

Monitor also the drag coefficient on the cylinder.

*Main Menu > Solve > Monitors > Force...*

Select _cylinder_ under {color:#660099}{*}{_}Wall Zones{_}{*}{color}. Under {color:#660099}{*}{_}Options{_}{*}{color}, select {color:#660099}{*}{_}Plot{_}{*}{color} and {color:#660099}{*}{_}Write{_}{*}{color}. Note that {color:#660099}{*}{_}Plot Window{_}{*}{color} is 1. 

h4. Setting Reference Values

To plot C ~d~, we need to set the reference value.
{latex}
\large
$$
C_d = {1 \over 2}{{Drag} \over {{\rho_{ref}} {V_{ref}}^2 {Area}}}
$$
{latex}
{info:title= }Note that cross sectional area for a 2D cylinder is the diameter of the cylinder.}
{info}
*Main Menu > Report > Reference Values...*

Under {color:#660099}{*}{_}Reference Values{_}{*}{color}, change {color:#660099}{*}{_}Area{_}{*}{color} to _2_, {color:#660099}{*}{_}Density{_}{*}{color} to _1_, {color:#660099}{*}{_}Velocity{_}{*}{color} to _1_ and {color:#660099}{*}{_}Viscosity{_}{*}{color} to _0.1_.
\\

!step5_img007.jpg!

This completes the problem specification. Save your work:

*Main Menu > File > Write > Case...*

Type in {{cylinder.cas}} for {color:#660099}{*}{_}Case          File{_}{*}{color}. Click {color:#660099}{*}{_}OK{_}{*}{color}. Check that          the file has been created in your working directory. If you exit FLUENT          now, you can retrieve all your work at any time by reading in this case          file.

h4. Iterate Until Convergence

Start the calculation by running 1000 iterations:

*Main Menu > Solve > Iterate...*

In the _Iterate Window_ that comes up, change the {color:#660099}{*}{_}Number          of Iterations{_}{*}{color} to {{1000}}. Click {color:#660099}{*}{_}Iterate{_}{*}{color}.

The residuals and drag coefficient for each iteration are printed out as well as plotted in          the graphics window as they are calculated.

[!step5_img005sm.jpg!|^step5_img005.jpg]

{newwindow:Higher Resolution Image}

Note that cross sectional area for a 2D cylinder is the diameter of the cylinder.}

https://confluence.cornell.edu/download/attachments/103733518/step5_img005.jpg?version=1{newwindow}


[!step5_img006sm.jpg!|^step5_img006.jpg]

{newwindow:Higher Resolution Image}