createNonlinearResidualEquationsComplex failed for fluid-model

[Per Öberg]

Problematic library: ​https://github.com/droberg/Modelica-MVEM.git

The library mentioned above contains three test-models of which two simulates great (same results as in Dymola) while the third has problems with createNonlinearResidualEquationsComplex

The examples that are working in openModelica 1.9.2 (And nightly r25516) are:

• energyPreservationTest.mo
• throttleSanityCheck.mo

The example that is not working is

• SIEngineTest

Code to reproduce:

cd("C:/Temp/Modelica-MVEM/MVEMLib")
clear()
loadModel(Modelica);
loadFile("package.mo")
instantiateModel(MVEMLib.Examples.SIEngineTest)
simulate(MVEMLib.Examples.SIEngineTest, stopTime=15, method="dassl", tolerance=1e-005)

Result:

...
[c:/dev/OpenModelica/Compiler/SimCode/SimCodeUtil.mo:3501:7-3501:46:writable] Error: Internt fel function createNonlinearResidualEquationsComplex failed for: ({-sIEngine.exhaustTemperatureDrop.InPut.dmXi[1], -sIEngine.exhaustTemperatureDrop.InPut.dmXi[2], -sIEngine.exhaustTemperatureDrop.InPut.dmXi[3], -sIEngine.exhaustTemperatureDrop.InPut.dmXi[4], -sIEngine.exhaustTemperatureDrop.InPut.dmXi[5], -sIEngine.exhaustTemperatureDrop.InPut.dmXi[6]}, sIEngine.adiabaticBurner.dummyOutput) = MVEMLib.Basic.Media.AdiabaticBurner.fuelAirMedium.calcBurnedFractions({sIEngine.adiabaticBurner.UnburnedInPut.dmXi[1], sIEngine.adiabaticBurner.UnburnedInPut.dmXi[2], sIEngine.forcedMassFlow.InPut.dmXi[1]}, sIEngine.exhaustManifold.gas.T)
[C:/Temp/Downloads/Modelica
...

[Vitalij Ruge]

Since the attempt in r25533 we get for

sIEngine._interCooler._gas_out._MM = DIVISION(1.0, sIEngine.interCooler.gas_out.Xi[1] / 0.0319988 + sIEngine.interCooler.gas_out.Xi[2] / 0.0319988)

a division by zero.