The error about the mass flow being out of the range of the curve, I've usually seen that before when there is backflow or some kind of spike in the pressure. Did you try doing a surface parameter on the fan faces to see what the calculated flow rate and pressure are?
Volume flow was slightly too high as the error indicates. 3,88e-6 m³/s instead of 3,33e-6 m³/s.
The pressure was at ~1 bar, which Looks fine to me.
I made another attempt to run the sim and now it worked....somehow.
I deletet the whole fan curve and set the volume flow constant over pressure, so just 1 value, no real curve.
It took about 4h with a reduced mesh (about 50% less cells), although the estimated time told me sth. about 20h.
I still wonder if it's the right way to misuse the internal fan as "pump" for the water loop? At least it seems to work in some way...
The function of the internal fan is to move the fluid inside the domain, you used it for its exact intended function. Just because it's called a "fan" doesn't mean it can only work on air.
Thanks =) I guess the word "fan" confused me together with that volume flow error.
So, at least 1 Problem is solved.
Now, after i implemented the fluid subdomain with the internal fan as a pump, i'm stuck with the next problem.
My fluid subdomain won't change it's temperature over time.
The Heat exchanger is set to fixed 10°C per outer wall condition.
All other solids and fluids are defined as 20°C as initial temperature in the wizard in the "initial conditions".
If i start the analysis without any heat sources, the closed water loop stays at 20°C.
I already tryed to set a additional initial condition in the flow simulation feature tree, but this didn't change the results.
Is it an issue of Flow Sim, that fluid subdomains can just be used at fixed temperatures?
Or did i set some properties the wrong way? (i bet it's the second one )
Check the thermodynamics parameters in your fan boundary conditions, make sure there isn't a constant temperature set.
Thanks, it was an unchecked check box in a resistance. I should've checked "use only for solids"....
So, Problem solved
Seems like my sim runs now way more realistic, altough the results are still about 1 or 2K too warm.
Damn, i've been to enthusiastic about this...still not solved.
I checked the tickbox in the thermodynamic parameters of the fans to "use outlet temperature" so i can't set an constant temperature anymore. As i understand from the online help, this should be fine by now.
If i run the simulation, the resulting water temperature is below the constant temperature set onto the outer wall, which is not possible.
I have no thermal loss to the surourrounding, as there is no surrounding defined.
The only path dissipating heat is between water loop, air loop and heat exchanger.
Do you have any idea where to search for the problem?
As it is an internal simulation, the temperature written in the properties of the fluid subdomain should be an initial temperature. And i cannot change it in the same way, as in the thermdynamic parameters of the fans.