Learning Forum

[cfd_learner]

Hello Dear,

 

I would like to simulate temperature variation on a fluid inside a pipe which is wrapped with a heating wire. Kindly suggest me the appropriate boundary conditions and simulation method (Ansys Mechanical Steady State Thermal Analysis or Ansys Fluent). The fluid, for instance, is water (static, not moving).

Here is the picture for reference and better understanding the problem.

 

[Rob]

You'll want Fluent (or CFX) for this. Make sure the wire has a finite contact area with the pipe outer wall (otherwise there will be no heat transfer) and that you're using a temperature dependent density for the fluid. Read up on natural convection and look for some examples to get you going and don't forget to switch gravity on!

[cfd_learner]

What will be the boundary conditions?

Water is flowing with 5m/s.

Pipe walls will be molded as convective heat flow?

Any minimal example?

[Rob]

So the water isn't static? Have a look for conjugate heat transfer (T-junction) tutorial and work through that: this will give you most of what you need. What is on the "outside" of the pipe? 

The wall between the fluid & solid will be "coupled" otherwise you'll not get any heat transfer. Also remember to create a multibody part (DesignModeler) or run share topology (SpaceClaim). 

[cfd_learner]

yes, water is flowing (5 m/s and 0deg C temp), not static. Outside of the pipe is a heating cable (100 degC) wrapped around. This whole setup is place in ambient environment with -20 deg C temperature. The objective is to heat the water flowing inside the pipe with the help of wrapped around constant temperature heating cable.

[Rob]

OK, the T-junction tutorials will cover most (all) of what you need. I'd suggest making the copper wire a square section to give you a finite contact between it and the casing. I'm also slightly surprised that there isn't any insulation on the outside of the system. 

The copper will need a source term adding to it of whatever W/m^3 is appropriate.