Research on non-conventional working fluids for space and terrestrial heat pipes

Abstract

In recent literature one of the most discussed arguments is about the study of such kind of solutions with particular surface properties, the main objective of this work has been focalized on the selection and analysis of  innovative working fluids through the measurements of surface tension, contact angle and thermal conductivity properties of different liquids in particular of binary and ternary mixture called “self-rewetting” with an anomalous dependency of surface tension with temperature and concentration. For the fist time has been produced another kind of carbon nanoparticles “Nanohorns” and different fluids has been produced with the dispersion of carbon nanoparticles with interesting properties. It has been demonstrated as the use of this kind of solutions (self-rewetting and nanoself-rewetting solutions) improve the thermal performances of two-phase heat transfer device in particular of groove commercial copper heat pipes. Finally a capillary structure has been manufactured with laser-engraving technique in order to valuate the effect of concentration gradient for a self-rewetting solution in capillary rising.