Evaluation of Thermophysical Data from Electromagnetic Levitation Experiments with Digital Image Processing

The EML/TEMPUS facility is an electromagnetic levitation facility for the containerless processing of liquid metals under microgravity. For the scientific evaluation of the microgravity experiments with the EML/TEMPUS facility an application software was developed by the DLR-MUSC. The software enables the experimenter to analyze the experiment performance by the visualization of synchronized facility and video streams of the microgravity experiments. The speed of the display of the data and video streams can be defined and ranges from realtime to a display in slow motion. For the scientific evaluation of surface tension and viscosities edge defection algorithms have been implemented. With the measured sample edge the diameter, area or ellipse parameters of the sample are calculated. A Fast Fourier Transformation is performed on the data and sample surface oscillation frequencies can be measured. Another implemented tool enables the experimenter to calculate the surface tension of the sample. For earthbound measurements correction terms can be applied. The evaluation algorithms are tested and improved with simulated sample oscillations with known oscillation modes and frequencies and specified rotation of the sample. With this method the effect of the angle of view and rotation on the spectra is investigated. Some evaluations and spectra from parabolic flight measurements are shown as example for the utilization of the software for the evaluation of data of TEMPUS / EML video data under microgravity conditions.