Hypergravity to explore the role of buoyancy in boiling in porous media

JS Lioumbas, J Krause, TD Karapantsios - Microgravity Science and …, 2013 - Springer
Microgravity Science and Technology, 2013Springer
Boiling in porous media is an active topic of research since it is associated with various
applications, eg microelectronics cooling, wetted porous media as thermal barriers, food
frying. Theoretical expressions customary scale boiling heat and mass transfer rates with the
value of gravitational acceleration. Information obtained at low gravity conditions show a
deviation from the above scaling law but refers exclusively to non-porous substrates. In
addition, the role of buoyancy in boiling at varying gravitational levels (ie from microgravity …
Abstract
Boiling in porous media is an active topic of research since it is associated with various applications, e.g. microelectronics cooling, wetted porous media as thermal barriers, food frying. Theoretical expressions customary scale boiling heat and mass transfer rates with the value of gravitational acceleration. Information obtained at low gravity conditions show a deviation from the above scaling law but refers exclusively to non-porous substrates. In addition, the role of buoyancy in boiling at varying gravitational levels (i.e. from microgravity—important to satellites and future Lunar and Martial missions, to high-g body forces—associated with fast aerial maneuvers) is still unknown since most experiments were conducted over a limited range of g-value. The present work aims at providing evidence regarding boiling in porous media over a broad range of hypergravity values. For this, a special device has been constructed for studying boiling inside porous media in the Large Diameter Centrifuge (LDC at ESA/ESTEC). LDC offers the unique opportunity to cancel the shear stresses and study only the effect of increased normal forces on boiling in porous media. The device permits measurement of the temperature field beneath the surface of the porous material and video recordings of bubble activity over the free surface of the porous material. The preliminary results presented from experiments conducted at terrestrial and hypergravity conditions, reveal for the first time the influence of increased levels of gravity on boiling in porous media.
Springer
以上显示的是最相近的搜索结果。 查看全部搜索结果