variavel0=<b>Mauricio Antoniazzi Pinheiro Rosa</b> - pinheiro@ieav.cta.br Instituto de Estudos Avançados - CTA
<b>Abstract.</b> Instability maps for density wave and excursive instabilities that may occur in open two-phase flow natural circulation loop are presented. The one-dimensional homogeneous equilibrium model of two-phase flow is assumed. Linear system stability criteria are used for the analysis. Heater power, liquid inlet subcooling, inlet and exit restrictions, heater length and loop height are taken as parameters for sensitivity analysis. The stable region appears at the lower left part of the Nsub vs. NpchFr0.5 dimensionless plane, bounded by two boundaries whereas the excursive instability region appears at the upper right part of the map. It has been confirmed that the density wave stability criterion automatically satisfies the excursive one.
<b>Keywords.</b> two-phase flow, density wave instability, excursive instability, loop instabilities, linear stability analysis.