Abstract
Accurate predictions of interfacial area concentration (IAC) are required for closure of the condensation phase change term. The interfacial area transport equation (IATE) can dynamically predict interfacial area concentration and is increasingly being used in the benchmarking of phase change flows over static based correlations which require a flow regime map. For higher flow regimes, the two-group two-fluid IATE model can separately model the transport of spherical bubbles and cap/slug bubbles. A modified formulation of the one-group and two-group two-fluid model with interfacial area transport equation was recently proposed for gas-dispersed condensing flows. Three datasets have been used for validation consisting of condensing two-phase flow data in the unheated section of a vertical annulus with conditions spanning a range of pressures, inlet subcoolings and mass fluxes for benchmarking the various IAC approaches. For bubbly flows, the coupled void transport - IATE simulation results in good agreement in the predictions of the void fraction and the interfacial area concentration under nearly all sixty conditions. Considering the proposed two-group two-fluid IATE model formulation, the group-2 Nusselt number correlation is investigated to account for the appropriate heat transfer length scale for group-2 bubbles. Validation of the proposed two-group two-fluid model against the new dataset shows good agreement with experimental data with significant improvement over the one-group IATE model for conditions with substantial group-2 void fraction throughout the simulation domain.
Original language | English |
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Article number | 103329 |
Journal | Progress in Nuclear Energy |
Volume | 124 |
DOIs | |
State | Published - Jun 2020 |
Externally published | Yes |
Funding
This material is partially based upon work supported by the Department of Energy under award number DE-NE0008573 .
Funders | Funder number |
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U.S. Department of Energy | DE-NE0008573 |
Keywords
- Annulus
- Condensation
- Interfacial area concentration
- Interfacial area transport equation
- Void fraction