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Parametric Sweep of parameters with different units

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Matthew Terracciano

Matthew Terracciano

September 1, 2010 8:28pm UTC

Parametric Sweep of parameters with different units

Hello I'm attempting to run a simulation in which the dimensions of the model(width and height) are parametrized as well as the amount of heat being transferred(Q) in the model. Under parameter names in the parametric sweep are: Dummy, Q, W, and H. The dummy is there to make the first value of the sweep monotonic as suggested in COMSOL help. The parameter values are inputted as: 1 45.6831[W/m] 1[m] .5[m] 2 51.92262[W/m] 1[m] 1[m] 3 55.83022[W/m] 2[m] 1[m] 4 61.8886[W/m] 2[m] 1.5[m] 5 60.35651[W/m] 2[m] 2[m].

What I have noticed is that with or without the dimensions attached to the parameter values in the parametric sweep comsol appears to just forget the dimensions when solving the model. If I cancel the simulation and go into the global parameters the variables have now been stripped of their dimensions; leaving other parameters these depend on for calculations with the wrong dimensions as well. My question is does this affect the simulation and am I performing this parametric sweep correctly to preserve the different dimensions being swept.

Thanks for your help,
Sincerely,
Matt Terracciano

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Ivar Kjelberg

Ivar Kjelberg
Moderator

September 1, 2010 9:53pm UTC in response to Matthew Terracciano

Re: Parametric Sweep of parameters with different units

Hi

I normally use only dimensionless variables as "parametrs" for sweep, I always multiply them by an amplitude value with units in the equations. This allows more freedom and avoids any unit conversion issues.

Try it out, it would probably make your case easier to debug and run.

It is correct that the first parameter value should be strictly increasing or decreasing, so keep your dummy (at least in 3.5, havnet check in V4)

--
Good luck
Ivar

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