Ministry for Research and Development. The microgravity level is about 10-4 g over a period of 360 seconds. This time will be extended to 540 seconds in 1990. The maximum g-levels are 12 g and 25 g during ascent and re-entry. Experiment Description There are two alternatives under consideration. In the first the experiment configuration is very similar to the one presented in the description of the drop tower experiment. By using adapter rings the experiment facility can be directly integrated into the TEXUS experiment bay. In this case there will be no extra development and testing necessary for the TEXUS flight and the drop tower experiment will have been the dress rehearsal. Due to the longer microgravity period the PCM canisters could be enlarged for the sounding rocket flight. In the second alternative the Isothermal Furnace (IF) of the MASER (Materials Science Experiment Rocket) sounding rocket project would be used. The cylindrical IF cartridge with a length of 30 mm and a diameter of 20 mm will be filled with the PCM and equipped with thermocouples. For both alternatives only the solidification process is of interest. Expected Results In the first alternative the expected results resemble those of the drop tower experiment described above. The longer microgravity period will allow a moderate cooling rate of the PCM canisters—similar to those expected in a REC/TES unit— and therefore intensify the TES relevant phenomena. The second alternative offers the additional possibility of investigating the solidification front by thermocouple measurements in the PCM, thus phenomena influencing the heat flux can be observed in real time. A sounding rocket flight with the mentioned objectives is scheduled for April/May 1991. Spacelab Experiment Background A spacelab experiment offers a microgravity level of 10~3 to 10~4 g over a period of about ten days and renders possible real time control of the experiment by an astronaut. The maximum g-levels during ascent and re-entry are moderate. Experiment Description The long microgravity duration renders a complete simulation of TES charging and discharging cycles possible. The proposed furnace is the Isothermal Heating Facility (IHF), which has already been flown during several spacelab flights. The cylindrical cartridge of the IHF with dimensions of 38.8 mm in diameter and 89 mm in length will be filled with the PCM and equipped with up to four thermocouples. In Fig. 8 two samples placed in the IHF are shown. When the PCM in the sample 1 is molten the furnace and cooling chamber are lifted, turned by 180 degrees, driven back and thus inverted in position whereas the samples stay fixed in the IHF. In the sample 2 the PCM is placed between two coaxial cylinders and thus can be cooled from outside like the standard sample but also through the inside cylinder wall. Therefore, also the case
RkJQdWJsaXNoZXIy MTU5NjU0Mg==