| dc.description.abstract | With the advancement of science and engineering the need for space restricted cooling devices
has increased. Closed loop pulsating heat pipe (CLPHP) is a new promising technology for
heat transfer of microelectronics. In it by simple mechanism heat is transferred effectively and
efficiently. The combination of processes like bubble nucleation, collapse, formation of vapor
plugs and slugs, agglomeration, dynamic instabilities and temperature/pressure perturbation,
etc. leads to exceptional heat transfer capability of the heat pipe. The aim of this research paper
is to better understand the operation of PHP through experimental investigations and obtain
comparative results for different parameters. A series of experiments are conducted on a closed
loop PHP (CLPHP) with 8 loops made of copper capillary tube of 2-3 mm inner diameter. The
heat pipe structure is using normal, CLPHP. Ethanol and Methanol is taken as the working
fluid. The operating characteristics are studied for the variation of heat input, filling ratio (FR)
and orientation. The single filling ratios are 0%, 30%, 50%, 70% and mixed filling ratio are DI
water, (50% water + 50% methanol), (60% Ethanol + 40% acetone), based on its total volume.
The orientations are 0° (vertical). This paper attempts to demonstrate the effect of variation of
different parameters on the same structure as well as the variation of thermal performance
depending on the presence of wire insert and fins on different structures. The experiment
demonstrates the effect of filling ratio and inclination angle and structural variation on the
performance, operational stability and heat transfer capability of ethanol as working fluid of
CLPHP. Important insight of the operational characteristics of CLPHP is obtained and
optimum performance of CLPHP using ethanol and Methanol is thus identified. Ethanol and
Methanol (Mixed) works best at 50% FR at wide range of heat inputs for all structures of
CLPHP. The best performance is obtained with normal structures. The optimum performance
of the device can be obtained at vertical position | en_US |
