uschna

Also for Modelica.Fluid.Pipes.BaseClasses.WallFriction.Detailed.massFlowRate_dp_staticHead?

There is also a jump in these functions at dp = 0. I don't know if there is an error in the interval 0

This problem is only for g_times_height_ab = 0 or small values (= 1e-10 this is continuous.

### Reasons for these: **Incorrect values:** In function massFlowRate_dp_staticHead: dp_zero < dp < dp_a: Computation of dm_flow_ddp_fric_zero using Modelica.Fluid.Utilities.regFun3: abs((y1d+y0d)-2 * Delta0)=100 * Modelica.Constants.eps, abs(y0d-y1d)>100 * Modelica.Constants.eps, (mu>0 and eta

Because the creation of this ticket was some time ago, I am not sure. But I suspect the problem does not only affect ModelicaTest.Fluid.TestPipesAndValves.BranchingPipes18 but also ModelicaTest.Fluid.TestComponents.Pipes.DynamicPipesWithTraceSubstances (pipe8.flowModel.WallFriction.massFlowRate_dp_staticHead -> pipe8.port_a.m_flow)....

I didn't understand offhand the algorithm in Modelica.Fluid.Utilities.regFun3. Therefore, I don't know what the problem is with the discontinuity at the edges and whether this can be fixed in Modelica.Fluid.Utilities.regFun3...