3D Thermal Data?

[777gne]

I'm completely new to thermography. I'm involved in a project that where we're introducing a heat source into the center a cube-shaped medium. We need to record the migration of the heat in all directions from the source over a fixed time interval (2-3 minutes).

The ideal end result would be an animation that models the heat flow in real time.

Can this be done using IR? It's beyond me, ultimately we'll be looking to find an experienced 3rd party to consult on this I'm just at the stage of determining the feasibility of what we're trying to do. I'm hoping those with more experience will chime in with their feedback.

 

[IRstuff]

Probably not, you'll get thermal energy from EVERYTHING in the line of sight of the pixel, so there's no depth perception here. How big is the cube? Is the media transparent in the IR? If not, it's a no-go. If it is, it's almost as bad, since what transmits IR won't emit much. It might be possible, if it's transparent in the IR to place some bits of black metal in the media. You might be able to pick up some emission from them as their temperature changes.


Your best bet might be a miniature RTD or thermocouple. Page 7 of

http://www.minco.com/uploadedFiles/...nd_Instruments/Miniature_Sensors/Ts103A_7.pdf

shows an RTD that's about 50 mils by 65 mils by 35 mils.

TTFN

FAQ731-376

 

[StephenGoodfellow]

Can you reveal what sort of medium your dealing with?

It might be an area better suited to computer simulation. If the medium is a liquid or gas you could try using CFD (Computational Fluid Dynamics). I'd also asume that there would be less work involved to turn this into a 3D animation.

There are various companies that specialise in this sort of thing.

 

[777gne]

Thank you both for your replies. We actually have several types of media, all of which are granular solid composites (think along the lines of typical soil). We're working with one cubic meter. The heat source is located at the center extending downward 1/2 meter.

There has been some mathematical modeling done for a similar study, however there's enough difference that we can't conclude it will apply to our situation.

We did consider using an array of RTD's to measure the temperature, however it will take quite a few to achieve a decent 3-dimensional resolution, and we'd need to build a support framework for them to ensure a controlled physical location over multiple trials. Ultimately this may be the direction we pursue if there isn't a more "off the shelf" approach.

 

[IRstuff]

Soil-like materials transmit IR not a whit, so that's a non-starter.

I would look for symmetries and apply RTD's in anticipation of the symmetries of the setup to minimize the number of devices.

TTFN

FAQ731-376

 

[JKEngineer]

If the materials are uniform then I think heat transfer simulation would be a far better way to go to generate the 3D animation. You would need the properties of the materials to do that. If the properties are not readily available, you could measure them with appropriate dedicated instrumentation or could derive it, at least in part, from infrared or thermocouple/RTD measurements of systems similar to your desired setup. A "2-D" system for such measurement might be more appropriate, for example.

Do you anticipate that the heat transfer through the voids in the matrix is a significant contributor?

IR could be used to monitor the outside of the cube to validate the simulation results from FEA or CFD.

I would be glad to discuss this further with you. Feel free to contact me through my website.


Jack M. Kleinfeld, P.E. Kleinfeld Technical Services, Inc.
Infrared Thermography, Finite Element Analysis, Process Engineering

http://www.KleinfeldTechnical.com