LEVEL SWELL AND VOID DISTRIBUTION IN A DISCHARGING VERTICAL VESSEL
The two phase phenomena occurring in a vessel, initially filled with saturated water and vapour and then rd discharged by a valve have been calculated with a simple code, called VESSEL. The modelling is based on some assumptions and simplifications which have been already successfully applied in the system code MULTIVOL: - same pressure for all volume elements - neglect of kinetic terms in the energy equation - simple discharge flow model - analytic expressions for physical properties - donor-cell approach - thermodynamic equilibrium In addition to the above, a drift flux model has been introduced where the velocity difference between the phases is assumed to be a function of void fraction. Special emphasis is given to the donor principle at the interface between two volume elements when liquid comes from one and vapour from the other side. Two different time steps are considered: a "large" step which is defined by the pressure drop during which the water properties are considered to be constant and a "short" step defined by Courant criteria. The modelling leads to short calculation times. The results are compared with level swell experiments at General Electric.
Bibliographic Reference: 1987 EUROPEAN TWO-PHASE FLOW GROUP MEETING, TRONDHEIM (NORWAY), JUNE 1-4 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING 1987 PAPER E 33415 ORA
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Record Number: 1989126026801 / Last updated on: 1989-01-01
Available languages: en