variavel0=<b>Maurício B. S. Valle</b> - mauriciobsv@iae.cta.br Instituto de Aeronáutica e Espaço - CTA
<b>Mauricio A. Pinheiro Rosa</b> - pinheiro@ieav.cta.br Instituto de Estudos Avançados - CTA
<b>Edson L. Zaparoli</b> - zaparoli@mec.ita.cta.br ITA
<b>Abstract.</b> In this work are presented the models and computational methodology developed for studying cooldown transients of cryogenic transfer lines. A homogeneous equilibrium one-dimensional two-phase flow model associated to a simple boiling heat transfer model was used for the cryogenic fluid flowing inside the pipe. The heat transfer during the cooldown process through the pipe walls and thermal insulation was calculated using heat conduction models. A finite difference approach was used for the spatial variable and the resultant set of ordinary differential equations in the time variable was solved using the fourth order Runge-Kutta method of integration. Comparisons of the numerical results against experimental ones showed that the calculated and experimental cooldown times are in satisfactory agreement.
<b>Keywords.</b> liquid propulsion, two-phase flow, boiling heat transfer, cryogenic fluids.