Measurement of Biomaterial Capillary Wick of Heat Pipe using Micro-CT Scan

In recent years, the use of capillary wick in heat pipe technology for various thermal management system has been growing rapidly. The capillary wick itself has the important role for improving the heat pipe performance. It can be made from a variety of materials, such as biomaterial in the form of coral (corallia encrusting). Before being applied, the capillary wick must be tested first through a series of conventional measurement methods to determine the heat pipe performance later. The purpose of this study is to measure its parameters i.e. porosity, permeability, and capillary pumping based on micro-CT scan and digital image processing. The results from conventional measurement showed that the biomaterial wick sample had varied permeability values ranging from 8.01071 mm(2), 8.53188 mm(2), 1.12424x10(-4) mm(2), and 1.6631x10(-4) mm(2), as well as porosity values of 7.8%, 8.3%, 33.12%, and 33.5%. Meanwhile, the results from micro-CT scan showed that its porosity values were 10.64% and 37.8%. Kozeny-Carman equation was used to determine the permeability based on porosity result from micro-CT scan. The calculated corresponding wick permeability reached the value of 9.76 m(2) and 1.68 x 10(-4) m(2), while its maximum capillary pumping rate were 0.047 g/s, 0.031 g/s, 0.104 g/s, and 0.127 g/s. The differences of both results from conventional measurement and micro-CT scan were in the range of +/- 5%, thus it could be acceptable.