In this paper a improvement in the heat exchange of a solar Stirling engine
during the compression phase was studied. The viability of using nanoparticles as
ceramic oxide (Al2O3 in water) at different concentrations instead of conventional
refrigerants (water or air) was evaluated. Since these systems could behave as non-
Newtonian fluids the dynamic viscosity was measured, as well as other thermophysical
properties. The results showed that the convective heat transfer coefficient could raise
one order of magnitude respect to the conventional heat transfer fluids at moderately
volume fractions (over 0.15).