Magnetic field control of cryogenic heat pipes
This paper deals with cryogenic heat pipes controlled by static magnetic field. Heat pipe is an equipment which allows a very effective heat transport. They are commonly used in electronic devices and in many other types of equipment as well. Some applications require heat flow controllability. For that purpose heat pipes are modified to many different constructions with variable heat conductance. Magnetic field control of heat transport is a new solution researched in a few laboratories in the world and still not practically applicated. According to the results of some experiments, implemented in our laboratory and several another laboratories, it seems to be possible to control heat transport in chosen types of heat pipes by a static magnetic field. The cryogenic heat pipe filled with pure oxygen has been made for that purpose and a testing device has been arranged as well. We have found out that the heat transport efficiency of the heat pipe has rapidly decreased by a magnetic field exposure. Some interesting results of our experiments will be presented in this paper.
Working Fluid Quantity Effect on Magnetic Field Control of Heat Pipes
This paper deals with heat pipes controlled by a static magnetic field and with an important side effect – the quantity of working fluid. Heat pipes are able to provide very effective heat transport. Several standard regulation methods are commonly used for this purpose. In previous experiments implemented in our laboratory, we have observed the significant influence of a magnetic field on the heat conductance of the selected heat pipe. A special heat pipe was manufactured for this purpose and pure oxygen was chosen as a working fluid, due to its suitable magnetic properties. The heat pipe operation and the magnetic field control depend on various parameters. This paper is focused on the influence of the quantity of working fluid. Some important results of our experiments are presented and discussed.
Effects of magnetic fields on flames and gas flow
Effects of magnetic fields on combustion and gas-flow were studied. Methane, propane and hydrogen gases were burned, and flames of these gases were exposed to gradient magnetic fields up to 1.6 T and 220 T/m. Flames bent so as to escape from magnetic fields of higher intensities. Apart from the combustion experiments, flows of gases such as carbon dioxide and oxygen were exposed to magnetic fields up to 2.2 T and 300 T/m. The flows of these gases with a flow velocity 20-140 ml/min were blocked or modified by the magnetic fields. The changes of flame-shape and gas-flow by magnetic fields are understood to be the result of the role of oxygen. Under the intensities of magnetic fields concerned, oxygen gases as paramagnetic molecules are not concentrated but are aligned so as to make a "wall of oxygen". The wall of oxygen presses back flames and other gases.