3. Results and discussion
Experimental results of heat-transfer rate have been presented
of a thermosyphon using silver nanofluid in the vertical position in
order to ascertain the effect of each dimensionless parameter,
respectively.
3.1. Effect of Archimedes number (Ar) and Grashof number (Gr) values
on heat flux
Ar determines the motion of fluid and solids due to density differences.
Shown in Fig. 2. Gr is a dimensionless number in fluid
dynamics and heat-transfer which approximates the ratio of the
buoyancy to viscous force acting on a fluid. Shown in Fig. 3 it can
be seen that the diameter increases as the heat flux slightly decreases
because the boiling phenomenon approaches pool boiling
and at pool boiling high heat-transfer rate occurs. On the other
hand, at a high diameter, the boiling phenomenon approaches boiling
inside a confined channel at which low heat-transfer rate occurs.
The small diameter, as opposed to a large diameter, causes
nanofluid to have less buoyancy.