Elmer Discussion Forum

since the Temporal part works fine, the problem is getting past the Spatial_1 part. This part needs a local derivative (dH/dT), which I guess is hard to guess at numerically for data that isn't definitely piecewise linear. Hence the ListGetDerivValue calls DerivateCurve which uses the points in a ta...

I'll just keep a running commentary here: tracing back the function call, the main problem I see: !------------------------------------------------------------------------------ !> Gets a real derivative from. This is only available for tables with dependencies. !------------------------------------...

ok, put a bunch of breaks in at the various points it pulls enthalpy/heat capacity. it appears the problem is within the EffectiveHeatCapacity subroutine. the first time through the transient model, because there is no previous timestep, even with Phase Change Model = 'Temporal' it instead uses 'Spa...

some more info. Trying to debug, I grabbed the HeatSolve.scr and inserted a Pause at 1191 inside the IF after checking for the condition to reduce the timestep. I had it print out the nodal temperatures and the temps from the previous time step. When using the adaptive stepping, and the enthalpy tab...

well, he said he's getting the error on attempting to read in the value: ! read in var var = ListGetConstReal( Model % Simulation, 'var', found) IF(.NOT. found) THEN CALL Fatal ( 'myFunction', 'var not found') END IF I assumed he meant he was having trouble with syntax and was getting the 'var not f...

First thought, you named your variable "Variable 4" not 'var'. I just did a UDF where I had constants defined in the Material section, and then pulled them into the UDF. I used the following lines in the Material section to define them: ENTH1 = Real $E1$ ENTH2 = REAL $E2$ enth1 = GetConstR...

playing around with this more, tried making a UDF to do the same thing. here's the modified Materal section with all 3 options Material 1 Name = "PCM" Density = $rhos$ Heat Conductivity = $kths$ !simple linear enthalpy change !Enthalpy = Variable Temperature ! Real ! 0.0 0.0 ! $T1 E1$ ! $T...

so "Check Latent Heat Release = true" turns on an adaptive time stepping routine that will reduce the timestep by half and then reruns the timestep if it detects that the phase front has moved farther than a single element. If I use a table to define enthalpy, this works well. It runs 50 t...

just for completeness, here's an example BC block from one of my heat flux BC runs: Boundary Condition 4 Target Boundaries(1) = 4 Name = Cooling Heat Flux BC = True Heat Transfer Coefficient = $htc$ External Temperature = 100 End That has a constant value for the HT Coefficient (a variable defined e...

Heat Flux BC is generally set to True or False. Then if it's True it looks for either a Heat Flux = "x" or a Heat Transfer Coefficient = "x". In addition, when applying a Heat Transfer Coefficient, I've also always used an "External Temperature = x " keyword to complete...