NaN issue in model for kc_roundTube

[maltelenz]

The csv file ModelicaTest/Fluid/Dissipation/Verifications/HeatTransfer/HeatExchanger/kc_roundTube/kc_roundTube.csv in the reference result repository contains a nan in the first row of data.

Is this expected? What should it be interpreted as?

[beutlich]

@wischhusen There is a floating-point overflow at simulation start time for Nu[3] in Modelica.Fluid.Dissipation.HeatTransfer.HeatExchanger.kc_roundTube_KC which is not covered. Therefore, either the test model ModelicaTest.Fluid.Dissipation.Verifications.HeatTransfer.HeatExchanger.kc_roundTube or the called function Modelica.Fluid.Dissipation.HeatTransfer.HeatExchanger.kc_roundTube_KC need to be fixed.