Thermal analysis in Ansys

[daimen]

Hi, first of all, i'm totally new with Ansys (v14) and would be very happy if someone could guide me through how I shall solve this problem, so this is what I want to do:

1 - I have modelled a tank in ProE, and managed to export it to Ansys (yeah!)

2 - The tank is made of construction steel and will contain water at 46 degrees celsius.

3 - Now I want to add a insulation material on the outside of the tank, around 100mm with an thermal conductivity at 0,12.

4 - The tank will be placed in water with a temperature at 4 degrees celsius.

5 - I want to calculate how long time it will take before the water inside the tank will come below a given temperatur, lets say 20 degrees.

Is this possible? Would be very, very happy if someone could give me some guidelines.

 

[flash3780]

There's an excellent tutorial of a transient thermal analysis in the Ansys APDL help files. I'd start by walking through that.

It may be worth noting that ANSYS will not be able to account for mass transport within the tank directly, though you can apply surface effect elements to the interior with applied HTCs and connect them to a mass node which will bookkeep the energy properly.

My experience has been that Workbench just isn't there yet when it comes to thermal problems, so I'd definitely tackle this in Ansys MAPDL.

Also, if your tank is axisymmetric, be sure to take advantage of that; it's always better to make a 2d model if you can.

I think you'll do well to become familiar with surface effect elements unless your Rayleigh number is extremely small and you can assume that the water acts as a solid.

I previously posted some information about using SURF152 (surface effect) elements here:

http://www.eng-tips.com/viewthread.cfm?qid=290824

Sheldon (from ANSYS) has great information on his website that you may want to check out, here:

http://ansys.net/?mycat=search&mytype=Tips&mycategory=HeatXfer

We also had a pretty good discussion about using surface effect elements (albeit for ambient radiation rather than convection) here:

http://www.eng-tips.com/viewthread.cfm?qid=302121

Hope that helps.

-Chris