Abstract
The two-group two-fluid model with interfacial area transport equation has been developed to improve the prediction of void fraction and heat transfer characteristics in two-phase systems. In the one-dimensional formulation, a closure relation is required for the group-1 and group-2 area-average local relative velocity. Furthermore, in the case of the modified two-fluid model with the gas-mixture momentum equation, the group-1 and group-2 void weighted gas velocities must be calculated with additional closure relations. The drift-flux general expression is extended to two bubble groups in order to describe the group-1 and group-2 void weighted gas velocities and area-averaged local relative velocities. Correlations for group-1 and group-2 distribution parameters and drift velocities are proposed and evaluated with a two-group boiling dataset taken in an internally heated annulus. The proposed distribution parameters show an average agreement within ±5%. The overall estimation of group-1 and group-2 void weighted gas velocities calculated with the newly proposed two-group drift-flux general expression shows an average agreement within ±16% of the measured value. The equations obtained for area-averaged relative velocity of group-1 and group-2 bubbles were simplified by neglecting covariance in void fraction. This assumption was compared with the experimental database and resulted in an average error within ±13%.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 6121-6129 |
| Number of pages | 9 |
| Journal | International Journal of Heat and Mass Transfer |
| Volume | 55 |
| Issue number | 21-22 |
| DOIs | |
| State | Published - Oct 2012 |
| Externally published | Yes |
Keywords
- Annulus
- Boiling
- Drift flux model
- Relative velocity
- Two-fluid model
ASJC Scopus subject areas
- Condensed Matter Physics
- Mechanical Engineering
- Fluid Flow and Transfer Processes