Investigation of MHD Impact on Argon Plasma Flows by Variation of Magnetic Flux Density

Abstract

Abstract:The interaction between a probe body and argon plasma flow is investigated to examine to what extent the probe head temperature and the bow shock distance can be influenced by applying a strong magnetic field. The experiments are performed using a strong permanent magnet installed inside a probe body with a spherical, coated probe head. Former investigations showed strong influence on the bow shock geometry but also on the inflow plasma jet. Several boundary conditions have been varied to evaluate their influence on the experiment. For an uncoated probe head the measured MHD impact was found to be of the same order of magnitude as for the coated case. Electrical isolation of the probe toward the vacuum chamber yielded only slight influence. The variation of the field strength was achieved by changing the amount of magnet segments installed. Pictures were analyzed to document the MHD interaction for each test case. It was found that the bow shock distance increased and the temperature of the probe head decreased while increasing the magnetic field density. This analysis precedes a thorough characterization of the plasma condition.

A Magnetohydrodynamic enhanced entry system for space transportation: MEESST

“…Due to less reliance on physical TPS on the spacecraft, the risk associated with mechanical impacts or other mechanical damage to the outside of the TPS is also decreased, a very important consideration especially for human-rated spaceflight applications as they are planned for the next decades by several space agencies and even commercial entities. MEESST can achieve this by leveraging MHD to reduce heat flux by a considerable margin, with up 30% lower heat flux being experimentally achieved previously in a test using an Argon atmosphere at IRS [10] . This is set to be further experimentally examined with more accurate representations of the conditions in the atmospheres of both Earth and Mars within the MEESST project through experimental capabilities of the VKI and the IRS.…”

“…In particular, the bow shock is displaced, keeping hot particles of the plasma further away from the spacecraft surface as illustrated in Fig. 4 which shows an experiment with argon as test gas [10] . This can lead to significantly lower surface thermal loads, therefore drastically reducing the TPS requirements.…”

Magnetohydrodynamic Enhanced Entry System for Space Transportation (MEESST) as a Key Building Block for Future Exploration Missions

“…Due to less reliance on physical TPS on the outside of the spacecraft, the risk associated with mechanical impacts or other mechanical damage to the outside of the TPS is also decreased, a very important consideration especially for human-rated spaceflight applications as are planned for the next decades by several space agencies and even commercial entities. MEESST achieves this by leveraging MHD to reduce heat flux by a large margin, with up 30% lower heat flux being experimentally achieved previously in a test using an Argon atmosphere at the Institute of Space Systems (IRS) [13]. This is set to be further experimentally examined with more accurate representations of the conditions in the atmospheres of both Earth and Mars within the MEESST project through experimental capabilities of the VKI and the IRS.…”

Comparison of Plasma Magnetic Field Interactions in a Static and Dynamic Plasma Facility

“…An important concept is how the magnetic field can affect the plasma shock in front of a spacecraft during atmospheric entry. Emission spectroscopy measurements of the bow shock region in front of a blunt probe body suggest that a magnetic field with the magnetic dipole axis parallel to the flow can increase the bow shock distance by as much as 13% [3][4][5][6] . Similar effects have been observed using an absorption spectroscopy setup [7][8][9] .…”