HEPP seminar summer 2025 #5: A. Bonciarelli / S. Estermann / A. Kilavuz

Monday 10 Nov 2025, 16:00 → 17:00 Europe/Berlin

HGW-GGH / GAR-D2

Daniel Told (IPP-Garching), René Bussiahn (IPP Bereich Greifswald)

https://eu02web.zoom-x.de/j/63778308490?pwd=UmmdpAfwf3LhqmoQO9MbTjVYN3kW14.1

 

ID: 637 7830 8490

Code: 492343

 

16:00 → 16:15 A. Bonciarelli (I): Localized probe measurements across magnetic islands: implications for divertor operation in W7-X

Speaker: Alice Bonciarelli (IPP Bereich Greifswald)

IntroductoryTalk_HEPP.pdf

16:15 → 16:30 S. Estermann (I): tba

Speaker: Sebastian Estermann (IPP-Garching)

2025-11-10_HEPP Intro Talk.pdf

16:30 → 17:00 A. Kilavuz (P): Investigation of Wall Boiling Models for High Heat and Mass Flux Fusion Relevant Flow Conditions

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.

Speaker: Ahmet Kilavuz (IPP-Garching)

HEPP_Progress_Presentation_KILAVUZ_Final.pptx

Abstract:

Divertor targets in fusion reactors are exposed to extreme heat fluxes where subcooled flow boiling may govern 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 parameter models with validation against high-heat-flux fusion-relevant experimental data. 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.