Target thrust measurement for applied-field magnetoplasmadynamic thruster

Abstract

In this paper, we present a flat target thrust stand which is designed to measure the thrust of a steady-state applied-field magnetoplasmadynamic thruster (AF-MPDT). In our experiments we varied target-thruster distances and target size to analyze their influence on the target thrust measurement results. The obtained thrust-distance curves increase to local maximum and then decreases with the increasing distance, which means that the plume of the AF-MPDT can still accelerate outside the thruster exit. The peak positions are related to the target sizes: larger targets can make the peak positions further from the thruster and decrease the measurement errors. To further improve the reliability of measurement results, a thermal equilibrium assumption combined with Knudsen’s cosine law is adapted to analyze the error caused by the back stream of plume particles. Under the assumption, the error caused by particle backflow is no more than 3.6% and the largest difference between the measured thrust and the theoretical thrust is 14%. Moreover, it was verified that target thrust measurement can disturb the working of the AF-MPD thruster, and the influence on the thrust measurement result is no more than 1% in our experiment.

Integrated study on the comprehensive magnetic-field configuration performance in the 150 kW superconducting magnetoplasmadynamic thruster

“…Directly measuring the thrust of an MPDT is technically very difficult due to its cumbersome power supply and feeding systems. The target measurement method is an indirect method that has been implemented and improved continually by our research team 31 . Its schematic diagram is shown in Fig.…”

Impulse Measurement Methods for Space Micro-Propulsion Systems

“…Calibrate the horizontal displacement and standard force of the elastic beam through the calibration device, establish the corresponding functional relationship, and realize the accurate measurement of different thrust sizes. Most target structures are equivalent to simple pendulum structures, and their motion characteristics are similar to the pendulum force formula [17,18].…”

Electric Propulsion Methods for Small Satellites: A Review

“…Magnetoplasmadynamic thrusters (MPD) are the most powerful of the electric thrusters [106]. Although their development typically requires rare, large and expensive vacuum test chambers [24].…”

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