Hi,

I'm trying to simulate a case where water is pumped from below sea level into an open tank/lake higher in the terrain. See figure below:



I'm trying to simulate this in Modelica (see below), but when I set the height difference in the pipe != 0 it does not simulate because of initial conditions (see error message just below). For reference, the pipe is set to not to allow reverse flow.

The following assertion has been violated during initialization at time 0.000000
til_LV1.flowModel.m_flows[1] > (-til_LV1.flowModel.m_flow_small)
Reversing flow occurs even though allowFlowReversal is false
simulation terminated by an assertion at initialization
Simulation process failed. Exited with code -1.



Are there any good way of simulating this setup in Modelica such that I don't get any reverse flow in the simulation?