Generalization of the HEM Solver Beyond the Edwards Test

Determine whether the homogeneous-equilibrium-model solver fixes developed for the Edwards blowdown test remain effective for the Marviken tests, natural-circulation tests, and the Zhang–Brooks validation cases, thereby establishing that the solver is not effective only for the Edwards nuclear-engineering use case.

Background

The paper presents preliminary verification and validation of a reduced-order one-dimensional homogeneous-equilibrium-model solver derived from the Outram-Foam rhoPimpleFoam and rhoCentralFoam implementations. The solver reproduces the general pressure-depressurization trend in the Edwards–O’Brien blowdown test, but the authors explicitly question whether the numerical fixes are physically and numerically transferable beyond that benchmark.

The proposed unresolved validation targets are the Marviken tests, natural-circulation tests, and the Zhang–Brooks case, for which nodalisation and results are available. These tests would assess whether the solver’s apparent success reflects general model and algorithmic validity rather than case-specific debugging adjustments.

References

However, it remains to be seen if such fixes can work outside the domain of the Edwards test. If the exact same HEM solver could work for the Marviken tests , as well as natural circulation tests , then one can know that this solver works sufficiently well and did not just receive random AI fixes that made it useful for Edwards but useless for other nuclear engineering use cases.

— Agentic Porting, Construction and Initial Verification and Validation of Libraries within the Open Source Unified TRAnsient Multi-Phase Advanced Reactor simulation Kit (Outram Park) Part I: Thermal Hydraulics  (2608.17504 - Ong et al., 18 Aug 2026) in Section 6, Future Work, subsection “Verification and Validation”