A. Bonciarelli (I): Localized probe measurements across magnetic islands: implications for divertor operation in W7-X

• Alice Bonciarelli (IPP Bereich Greifswald)

S. Estermann (I): tba

• Sebastian Estermann (IPP-Garching)

A. Kilavuz (P): Investigation of Wall Boiling Models for High Heat and Mass Flux Fusion Relevant Flow Conditions

• Ahmet Kilavuz (IPP-Garching)

Divertor targets in fusion reactors are exposed to extreme heat fluxes where subcooled flow boiling governs heat transfer. Reliable prediction of wall temperatures and heat transfer coefficients under such conditions requires boiling models applicable beyond conventional parameter ranges. In this study, existing wall-boiling formulations are systematically investigated under fusion-relevant pressures, mass fluxes, and subcoolings. The analysis combines computational evaluation of bubble-scale parameters with validation against high-heat-flux experimental data for smooth and enhanced cooling channels. Results show that conventional models tend to overpredict wall superheats due to weak coupling between convective and transient heat-transfer mechanisms. To enable future implementation of refined models, a dedicated CFD framework is being developed in OpenFOAM, allowing direct integration of modified wall-boiling formulations into three-dimensional simulations. The combined insights provide a physically consistent and computationally applicable basis for predicting subcooled flow boiling in advanced water-cooled divertor components.