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murali August 23, 2008 00:47

inlet velocity boundary condition
hi all how to give in cfx-11:inlet velocity boundary condition

Glenn Horrocks August 24, 2008 21:22

Re: inlet velocity boundary condition

Basic stuff like this is covered in the tutorials which come with CFX.

Glenn Horrocks

Rogerio Fernandes Brito August 25, 2008 06:55

Re: inlet velocity boundary condition
Step 4: Defining Boundary Conditions:

The next icon, , is used to specify the boundary conditions for the model. Again, I will show you how easy it is to do this in CFX-Pre. The boundary names on the grid for this mixing model were defined in ICEM CFD. Click on this icon to open up the Create Boundary menu. Enter the name INLET HOT for the boundary name and WATER is the only domain that you can pick so click on the OK button. The Edit Boundary: INLET HOT in domain: WATER window will open up. Under the Basic Setting tab, ensure that INLET is chosen for the Boundary Type and INLET1 is selected for the Location. Under the Boundary Details tab leave the Subsonic setting for the Flow Regime Option. Enter a value of 1 m/s for the Normal Speed under Mass and Momentum. Note: just enter the number as the units are selected in the pull-down menu to the right. Ensure that Medium (Intensity = 5%) is set for the Turbulence Option and enter a value of 350 K for the Static Temperature under the Heat Transfer Option. Click Ok and the first inlet boundary is done.

Click on the boundary condition icon again and enter the name INLET COLD for the boundary name. Again, WATER is the only Domain setting. Click OK to open up the Edit Boundary: INLET COLD in domain: WATER window. Under the Basic Settings tab, Inlet should be the Boundary Type and select INLET2 for Location. Under the Boundary Details, enter 1 m/s for Normal Speed and 300 K for the Static Temperature. Click OK and the second inlet boundary is done. There is one more boundary to define. Click on the boundary condition icon once more and enter the name OUTLET for Name. Change the Boundary Type to OUTLET and select OUTLET for the Location under the Basic Setting tab. Change to the Boundary Details tab. Enter a value of 0 for the Relative Pressure using the Average Static Pressure Option under Mass and Momentum. Click OK and the last boundary condition is done. One thing you probably noticed is that the boundary you selected under Locations was highlighted for ease of recognition. Also, as soon as you click on OK, arrows pointing inwards appear for the INLET boundary condition type while arrows pointing outward appear for the OULET boundary condition type. These are nice features that can help greatly for setting up more difficult models. You may be asking about the other remaining surfaces of the model. Do they need to be defined? It depends on the model. In this example, the remaining surfaces are all walls and by default any surface that is not defined as we did above becomes a wall and is also adiabatic. This is what we want here so we do not need to define any further boundaries. Of course, if the walls had a temperature and were different for each tube, then we would need to define a few more boundaries. To make setting up the model easier, try to give your grid boundaries names that are meaningful when building your mesh, i.e. INLET1, INLET HOT instead of BOUNDARY1.

Source: "The FoCÚs" - December 13, 2006, A Publication for ANSYS Users, Issue 54.

murali August 31, 2008 01:58

Re: inlet velocity boundary condition
Mr.Rogerio I have to paramiters:inlet tangential velocity,fluid velocity,Vtheta,where i will give in CFX-11,AND I know pressure also.

hhh August 3, 2012 06:05

velocity inlet in fluent
Dear friends,
In fluent, For analysis of 2D naca0012 airfoil velocity inlet we give vcostheta in x component & vsintheta in y component, v is inlet velocity.

1)here i start analysis of 3D wing, for that i take naca 0012 airfoil & extrude 100mm, in gambit and analysis in fluent i have doubt how to set velocity inlet, here i consider my velocity is 50m/s, then what is xyz component,please let me know.

2)if you consider 3D wing, (vtantheta for z component) is correct or wrong, please let me know.

2) how to find angle of attack for 3D wing? please let me know

ghorrocks August 3, 2012 08:56

Try the Fluent forum - and do not duplicate post. It is very annoying.

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