[Aika]

Hi all

I have a problem with heating part of pipeline. Ihave a 9 m pipeline and i need to heat just 0.5 m from beginning. So firstly when part of pipeline is heated the temperature and viscosity of oil in pipe should change. When i heat, in my case not only part but all pipeline is heated. Could u help me with this
Thank in advance

[me3840]

You need to separate the pipe at the 0.5m mark to ensure conduction does not occur to the rest of the pipe.

[Aika]

Thanks a lot. So for this should I greate a new region or not? I tried heat only inlet region, but I have the following mistake

A floating point exeption has occured. ......

[Aika]

And how I can do the separation at 0.5m?
many thanks

[Aika]

I am so so sorry. Could you be more presicely, how I can separate the region?

any help will be appraciated

[me3840]

Create just a box that encompasses the part of the pipe you want to split, and then do a boolean subtract with the part.

Though if you're getting a floating point exception, there's probably something wrong with your setup.

[DaveyBaby]

Hi!

For a metal pipe, there should be a significant amount of heat transfer along the solid that you need to take into account.
Have a look at:
Tutorial Guide > Heat Transfer and Radiation > Conjugate Heat Transfer: Heated Fin
This shows you some of the concepts that you will need.
Field functions are very useful for defining boundary conditions.
Using Tools > Using Field Functions > Field Function Programming Reference
will give you the syntax you need to define something of the type:
if(distance<x2 and distance>x1) "heat"
else "no heat".

[Aika]

Many thanks

I will try

[Aika]

Hi,

Thx a lot for your help. I've created 2 bodies and used boolean, but my 2 regions are calculated differently. Could u help?

[DaveyBaby]

Hi,
Have a look at
Defining The Simulation Topology > Working with Interfaces
You need to create an interface between the 2 regions, even if they are next to each other in the CAD model.

[ping]

if you are only want to input different heat values or temperatures locally then you don't need different regions but instead just a different boundary which can be done by imprinting in 3d-cad to separate the outside wall of the pipe into two surfaces

[Aika]

Hi ping

Thx a lot. I am a beginner

In my case the temperature of oil doesn't change, i din't know why. Initially I set up 500 C degree and oil temp should change between 500-300C degree. But initially in 1-3 steps oil temp becomes 300C.

And about the viscosity changing I couldn't have a result

I tried firstly with one region and set up fir inlet heat flux, so I have no a really result. If you have time could you review my model, many thx

[Aika]

Hi guys

Please help me. I simulate the water flow in cyclone (for now just water without sludge) and my model is working. But my initially setting parameters (constants) have changed totally. Thx in advance

[Aika]

Hi all

Could you help me with fiel function definition? I should create a field function for oil viscosity, because it changes due to temperature difference

How I can write a definition (scalar field)

I wrote $$Position[0] and after my simulation shows me an error

many thx

[DaveyBaby]

Hi! Star's help files are hard to follow, it's easy to end up going round in circles.
Type "Field function programming reference" for the header menu to all the syntax definitions you may need. This sounds simple, but it's hard to find in the help section by searching!

[Aika]

Hi,

thanks a lot

[ggulgulia]

Hello Aika

You can try seperating the boundary instead of creating entire region. Do the boolean operation as mentioned above and create a seperate boundary in the same region. Enable thermal conductivity/wall heat flux option under the boundary physics condition.

In case you want to go with seperate region, make sure that you are creating interface b/w solid-solid and solid fluid boundary.

Hope this was helpful

[Aika]

Thank you so much