packagePolytropic

Information

This example package contains a sequence of steps for constructing a nuclear reactor. The setup of this example is identical to Exercise2NuclearReactor.Adiabatic (see for problem description).

The final example model is provided in Exercise2NuclearReactor.Polytropic.Step9FinalResults.

This package uses the PolytropicPerfectGas model instead of the Adiabatic model. This helps to avoid implicit nonlinear equations, as long as the inlet state is known. Since the inlet state of compressor1 is unknown, the InverseBlockConstraints block is still required.

In Dymola 2026x Refresh 1 the nonlinear solver converges. In older Dymola versions (and potentially in OpenModelica) the nonlinear solver may only converge for considerInertance = false .

Polytropic.Step9FinalResultsReversed shows, that theoretically, the nonlinear equations can be avoided if the flow through compressor1 is reversed. This however requires to calculate a modified isentropic efficiency, which is impractical, unless eta_is = 1.

Contents

Name	Description
Step1Reactor
Step2Turbine1
Step3Turbine2
Step4Turbine3
Step5HeatExchanger
Step6Compressor1
Step7Compressor2
Step8Cooler1
Step9FinalResults
Step9FinalResultsReversed

Revisions

• 2026, by Raphael Gebhart (raphael.gebhart@dlr.de):
  Initial version.