Heat transfer enhancement by electric fields in several heat exchange regimes.
With the present article, the authors summarize over 15 years of work dedicated to studying the effects of the electrical and the gravitational force fields on two-phase and single-phase thermofluid dynamics. Results obtained on several microgravity platforms are presented and the role played by the electric field in the different heat transfer processes is analyzed. In particular, the regimes of nucleate boiling and film boiling are treated. Also, the parameters controlling the liquid-vapor interface instability and the main consequences regarding the critical heat flux (CHF) are outlined. In the final section, the promising technique of ion injection for efficient heat transfer enhancement in single-phase liquids is described, together with the main results obtained under different flow regimes and geometries. The following dielectrics were compared: R113, Vertrel XF, and FC-72 for the pool boiling research; again FC-72 and HFE-7100 for the single-phase convection heat transfer experiments.
Grassi
Walter
W
LOTHAR (Low Gravity and Thermal Advanced Research Laboratory), Department of Energetics L. Poggi University of Pisa, Via Diotisalvi, 2-56126 Pisa, Italy. w.grassi@ing.unipi.it
Testi
Daniele
D