id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc
4441	Incorrect calculation of stream variables	j.schulz@…	Vitalij Ruge	"The discrepancy in calculation will occur if a node connects more than two components and one component’s mass flow rate is explicitly set to zero. In case of three components with one component’s mass flow rate set to zero, the incorrectly calculated stream variable amounts to exactly 50 % of its proper value. If this component, the mass flow rate of which is set to zero, is removed, the stream variable will be calculated correctly.

The ZIP archive contains two packages: “StreamSolarSystem2” and “TILMedia”. The latter is included to provide necessary thermophysical property data. The “StreamSolarSystem2” package contains two system models: Running “System1” will deliver the incorrect result for the stream variable “pump.portA.hOut”. In “System1_withoutSensor” the component, the mass flow rate of which has been set to zero is removed, and, thus, the correct value for “pump.portA.hOut” will be calculated.

Other tools detect if a model sets the mass flow rate explicitly to zero, and treat them as if they were not existing. The inStream() value in the other connected models only refer to each other, not to the model with m_flow = 0. The treatment and behaviour of two connected models is exactly the same, as of three connected models with one having m_flow set to zero.
"	defect	closed	high	1.13.0	Backend	v1.11.0	fixed	stream variable, incorrect calculation