Hello,

I'm working on implementing a model on Dymola with TILSuite but I'm very new to the language and cannot pass this error.

The code is basically  the following and there are division by Zero on the bold lines. I think the problem lies on the variables Retp and Ftp. Should I somehow give them a value?

equation
  PipeInternalRoughness = 0.0015 "For Copper";

  Usg = (noEvent(abs(mdotHydraulic))*vapor/properties.VLE.d_v) / cellGeometry.hydraulicCrossSectionalArea;
  Usl = (noEvent(abs(mdotHydraulic))*liquid/properties.VLE.d_v) / cellGeometry.hydraulicCrossSectionalArea;
  Ugm = (0.35*sin(0) + 0.45*cos(0))*((g*hxGeometry.tubeSideHydraulicDiameter*(properties.VLE.d_l-properties.VLE.d_v))/properties.VLE.d_l)^0.5*(1-alpha)^0.5*C2*C3*1;
  Co = ((2 - (properties.VLE.d_v/properties.VLE.d_l)^2)/(1+(Retp/1000)^2))+(((((1+((properties.VLE.d_v/properties.VLE.d_l)^2)*cos(0))/(1+cos(0)))^0.5)^(1-alpha))^(2/5)+ Co1)/(1+(1000/Retp)^2);
  Co1 = (C1 - C1*sqrt(properties.VLE.d_v / properties.VLE.d_l)) * ((2.6 - beta)^0.15 - sqrt(Ftp)) * (1-massQuality)^1.5;
  C1 = if hxGeometry.portIsCircular then 0.2 else 0.4;

  beta = Usg / (Usg + Usl + Modelica.Constants.small);

  Retp=(properties.VLE.d_l * (Usg + Usl) * hxGeometry.tubeSideHydraulicDiameter) / properties.VLETransp.eta_l;
  1 / sqrt(Ftp) = -4.0 * log10((PipeInternalRoughness/hxGeometry.tubeSideHydraulicDiameter)/3.7 + 1.256/(Retp*sqrt(Ftp)));

  alpha = Usg / (Co * (Usg + Usl) + Ugm);


  C2 = if properties.VLETransp.eta_l/0.0001>10 then (0.435/(log10(properties.VLETransp.eta_l/0.001)))^0.15 else 1;
  C3 = if La < 0.025 then (La/0.025)^0.9 else 1;
  La = sqrt(properties.transp.sigma/(g*(properties.VLE.d_v - properties.VLE.d_l)))/hxGeometry.tubeSideHydraulicDiameter;