## Fluids

#### How do you extend a pipe with inner and outer surface to 5km in length?

• LeonLow
Subscriber

I have extruded the first plane to 500m to create the first part of my pipe. I extended the pipe to 1,000m by creating another plane on the end of my first pipe. When I try to extend the plane to another 500m, there is an error. Not sure why this is happening, please help!

The error is: Feature parameter too large.

Ansys Employee
Where are you extending? Is it DM or SpaceClaim?
Better use scale down model. Mesh it. Then read in Fluent. Then scale it up using Domain -- Mesh -- Scale
47.3.1. Scale Mesh Dialog Box (ansys.com)
Regards Keyur
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• LeonLow
Subscriber
I am using DesignModeler! My steps are Geometry, Mesh followed by Fluent. If I were to scale it down in SpaceClaim, will I be able to scale it back up to 5km? As far as I know, you need to connect a few 500 m pipes together to make it to 5 km because ANSYS only allows a part to be 500m maximum.

I tried using SpaceClaim but I am unable to find the anchor point for a circular pipe! Please help!
• Rob
Ansys Employee
DesignModeler has a large body option, and SpaceClaim doesn't seem to limit dimensions. Note, a 5km pipe will need a lot of mesh as you'll want 10-20 cells across the diameter and an aspect ratio of between 1 and 7 in the bulk mesh. What are you trying to model?
• LeonLow
Subscriber
I am trying to create a 2 simple models of
Case 1: 5km circular pipe in which the surface temperature is around 90 Degree Celcius and the fluid inlet temperature is 30 Degree Celcius. I would like to view the temperature contour across the circular pipe.
Case 2: 5km circular pipe with 1/4 of the pipe insulated from the surroundings and the other 3/4 is exposed to 90 Degree Celcius. All conditions same as Case 1.
• Rob
Ansys Employee
If it's straight and vertical (or gravity is off) then use 2d axi-symmetric in Fluent as you may then have enough mesh to model this.
• LeonLow
Subscriber
It is horizontal! Should I use SpaceClaim to do this?
• Rob
Ansys Employee
DesignModeler is fine, just turn on large model support. I assume you can ignore gravity?
• LeonLow
Subscriber
Thanks for helping! I just started using ANSYS last week. Will try to do this