PhD Thesis Defense M. Levêque – Hybrid pumping capillary mechanical two-phase loop

Event information

Start date :04/03/2020

End date :04/03/2020

Time :09:30

Location : salle des colloques - Bât. 3R2 - Université Toulouse III - Paul Sabatier, 118 route de Narbonne, 31330, Toulouse

PhD Thesis Title: « Experimental study and modeling of a hybrid pumping capillary mechanical two-phase loop »
By Marie Levêque

Doctoral School: MEGeP

Thesis of Toulouse III – Paul Sabatier University, prepared at LAPLACE laboratory and IRT Saint Exupéry.


This work presents a study on the pump assistance of a capillary two-phase loop. This coupling should permit to extend the operating range of these loops to environments with
demanding thermal and mechanical specification as it exists in aerospace applications. An experimental bench has been developed in order to investigate the coupling behavior of a
CPL (Capillary Pumped Loop) and a centrifugal pump in series. We found that the possibility to extend the pumping capacity from 10 kPa to 60 kPa, i.e. far further than the
evaporator limit (capillary limit). Thermal performance were increased by the additional sub-cooling from the pump. This coupling robustness was also observed during the application
of severe solicitations (power cycle, start-up). The system modeling showed that the vapor percolation/condensation process at the inlet of the evaporator significantly affected
the evaporator dynamics so that the reduction of these mechanism is decisive in order to optimize the system control. In a last part, preliminary results obtained for a pump placed
at the reservoir inlet were presented. We found that in this case, the system control became more difficult because of the liquid mass redistribution between condenser and reservoir. However,
modeling identified stabilizing factors (condenser performance, pressure drop, pump characteristic) which could permits the pump assistance of LHP (Loop Heat Pipe).