Computational Magneto-Hydro Dynamics of a Magnetic Flux Compression Reaction Chamber

Paper number

IAC-16,C3,5-C4.7,8,x32722

Coauthor

Mr. Gherardo Romanelli, TU Delft, Italy

Coauthor

Dr. Angelo Cervone, Delft University of Technology (TU Delft), The Netherlands

Coauthor

Prof. Andrea Mignone, Italy

Year

2016

Abstract

Pulsed fusion propulsion might finally revolutionise manned space exploration by providing an affordable and relatively fast access to interplanetary destinations. However, such systems are still in an early development phase ($TRL<2$). One of the key areas requiring further investigations is the operation of the magnetic flux compression reaction chamber which is the device that is meant to exploit the fusion energy and generate thrust. A fusion reaction is ignited within the chamber and part of the expanding plasma is reflected by the generated magnetic field to attain thrust in reaction. This working principle has yet to be extensively verified, and computational Magneto-Hydro Dynamics (MHD) is a viable option to achieve that.

Hence, one of the first ideal-MHD analysis of a a multi-coil parabolic reaction chamber (the latest reaction chamber design) has been completed  by employing a special code for computational astrophysics. As a result, we have been able to effectively reproduce the process of thrust generation and confirm the chamber operation. Furthermore, our results show that the chamber estimated performance is greatly affected by different ambient conditions: by reducing the ambient density of 2 orders of magnitude, the calculated specific impulse is 10\% higher. However, we could not find an asymptotic value of the performance due to a pointed out limitation of ideal-MHD. In fact, an extremely low density profile combined with the strong magnetic field results in the generation of relativistic Alfvén velocities which are not properly handled by ideal-MHD. That has prevented a further reduction of the ambient density which is still far higher than what of deep space vacuum.

Thus, implementing a relativistic MHD model has been found to be particularly important for the development of reaction chambers, as well as of steady-state magnetic nozzles in general. Indeed, despite numerical analyses of the latter are more numerous, relativistic considerations have not been extensively treated in the publications. Nonetheless, including such aspects might be fundamental to attain reliable performance estimations from which then derive experimental testing requirements as well as accurate mission scenario projections. Therefore, since a correct modelling of the reaction chamber operation is mandatory to achieve a complete design of the device, the results of this research are expected to be of great value for the progress of pulsed fusion propulsion, as well as of manned space exploration.

Abstract document

IAC-16,C3,5-C4.7,8,x32722.brief.pdf

Manuscript document

IAC-16,C3,5-C4.7,8,x32722.pdf (🔒 authorized access only).

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