Thermal Characteristics of Conventional and Flat Miniature Axially Grooved Heat Pipes

Abstract

A detailed mathematical model of low-temperature axially grooved heat pipes (AGHP) is developed in which the fluid circulation is considered along with the heat and mass transfer processes during evaporation and condensation. The results obtained are compared to existing experimental data. Both capillary and boiling limitations are found to be important for the flat miniature copper-water heat pipe, which is capable of withstanding heat fluxes on the order of 40 W/cm2 applied to the evaporator wall in the vertical position. The influence of the geometry of the grooved surface on the maximum heat transfer capacity of the miniature AGHP is demonstrated.

Flat Plate Heat Pipes: From Observations to the Modeling of the Capillary Structure

“…Besides, theoretical works are generally focused on capillary-driven flows and thermal models in ideal conditions, i.e. the system being optimally filled with liquid (Khrustalev and Faghri, 1995;Kim et al, 2003;Lefèvre et al, 2008).…”

A three-dimensional thermal-fluid analysis of flat heat pipes

“…The thermal resistance from the top wall surface of the flat heat pipe to the ambient environment can be defined as follows [7]:…”

“…Most one-dimensional analytical and numerical models focus on heat transfer performance and various limitations, especially the capillary limit in flat micro miniature heat pipes. Khrustalev and Faghri [7] developed a one-dimensional model for flat heat pipes with triangular grooves. The maximum heat transfer restricted by capillary limit was predicted.…”

On periodic two-phase thermosyphons operating against gravity

“…The two-phase devices operating against gravity which have been studied in the past are mostly capillary driven; these comprise conventional heat pipes [1][2][3], loop heat pipes [4,5] and capillary pumped loops. The latter two types are characterised by good performance and are only slightly influenced by gravity [6], but need high technology to realise the capillary structures, which are ex-* Tel.…”