Abo Bibliothek: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

A SINGLE LOOP PULSATING HEAT PIPE IN VARYING GRAVITY CONDITIONS: EXPERIMENTAL RESULTS AND NUMERICAL SIMULATIONS

Get access (open in a dialog) DOI: 10.1615/IHTC16.her.023891
pages 4877-4884

Abstrakt

The thermo-fluid dynamic behaviour of a Single Loop Pulsating Heat Pipe (SLPHP) has been characterized during the 66th ESA Parabolic. The SLPHP, with a 2 mm inner diameter, has been tested in bottom heated mode, varying the working fluid (FC-72 and ethanol), the heat power input (from 1W to 24W) and the gravity level (0.01g, 1g and 1.8g). Two transparent tubes connect the evaporator and the condenser, allowing local fluid flow visualization. A set of three-dimensional maps, derived from semi-empirical correlations usually adopted in literature to estimate the critical diameter at different gravity levels are drawn for the different fluids tested, liquid velocities and fluid temperatures. These maps are used to compare the flow velocity observed experimentally with the critical diameter value calculated. Additionally, an enhanced Volume of Fluid (VOF) model is utilised to simulate an imposed slug flow within a straight 2 mm inner diameter channel, replicating the same experimental conditions, with the primary aim to study the effect of the vapour bubble length and the liquid film thickness on the generated elongated bubble dynamics, in microgravity conditions.