This paper presents an experimental analysis of the heat transfer performance of a semi-arc heat pipe. Two circular wicklest heat pipes with similar hydraulic diameter and wetted perimeter to this semi-arc heat pipe were also tested for comparison. Methanol at saturation temperature 60° C was filled as the working fluid with 65% filling ratios of the evaporating section volume. The heat transfer mechanism, maximum heat transfer rate and effect of inclination angle were measured and discussed. The test results show that there is a dramatic temperature drop during the increasing heating power process for 4.4 mm circular tube. This temperature variation was not observed for the 2.4 mm tube and not so significant for the semi-arc heat pipe. There is no strictly dry out phenomenon for the semi-arc heat pipe within the tested heating power range. If we consider the heating power input that caused the adiabatic wall temperature keep increase as its maximum heat transfer rate, the test results show that flooding limits for different tubes at vertical orientation agree very well with those predicted by the Faghri et al.  correlation. Owing to the action of surface tension drainage in the sharp corner, it keeps the evaporating section of the semi-arc heat pipe wet and caused the evaporating thermal conductivity of the semi-arc heat pipe much higher than that of circular tubes. It is a very good design for applying in low inclination angle heat pipe operation.
|Number of pages||7|
|Journal||Proceedings of the Intersociety Energy Conversion Engineering Conference|
|State||Published - 2001|
|Event||Proceedings of the 36th Intersociety Energy Conversion Engineering Conference, IECEC - Savannah, GA, United States|
Duration: 29 Jul 2001 → 2 Aug 2001