Design of a Thrust Stand for Low Power Electric Propulsion

Faculty Mentor Name

Darrel Smith

Document Type

Presentation

Location

Jim and Linda Lee Planetarium

Start Date

5-10-2018 2:50 PM

End Date

5-10-2018 3:00 PM

Abstract

Electric propulsion (EP) has been gaining popularity due to the high efficiencies and specific impulse. These thrusters all follow the same general idea of converting stored electrical potential energy to kinetic energy for the craft; typically, this is accomplished by the acceleration of gas particles through three main methods, electrothermal, electromagnetic, and/or electrostatic. The specific impulse is the change of momentum per unit of propellant expended. While chemical propulsion produces a high change in momentum, they use much more propellant mass than an electric thruster. EP devices will typically produce very low thrust, which makes it difficult to measure thrust and impulse. This EP project focuses on designing and building a thrust stand capable of measuring thrusts ranging from nanoNewtons to milliNewtons. Due to the sensitivity of the forces, we hope to design and build a modular system that can be adjusted to accommodate the full range of forces. The initial design is based off of an inverted pendulum, with the thruster on the top of the pendulum. As it produces a thrust, the pendulum will begin to swing back, a linear variable differential transducer (LVDT) will measure the linear displacement, then give a signal to a voice coil that will push the stand back into place. The linear force of the voice coil will be proportional to the thrust of the thruster based on their relative distances from the center of rotation.

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Oct 5th, 2:50 PM Oct 5th, 3:00 PM

Design of a Thrust Stand for Low Power Electric Propulsion

Jim and Linda Lee Planetarium

Electric propulsion (EP) has been gaining popularity due to the high efficiencies and specific impulse. These thrusters all follow the same general idea of converting stored electrical potential energy to kinetic energy for the craft; typically, this is accomplished by the acceleration of gas particles through three main methods, electrothermal, electromagnetic, and/or electrostatic. The specific impulse is the change of momentum per unit of propellant expended. While chemical propulsion produces a high change in momentum, they use much more propellant mass than an electric thruster. EP devices will typically produce very low thrust, which makes it difficult to measure thrust and impulse. This EP project focuses on designing and building a thrust stand capable of measuring thrusts ranging from nanoNewtons to milliNewtons. Due to the sensitivity of the forces, we hope to design and build a modular system that can be adjusted to accommodate the full range of forces. The initial design is based off of an inverted pendulum, with the thruster on the top of the pendulum. As it produces a thrust, the pendulum will begin to swing back, a linear variable differential transducer (LVDT) will measure the linear displacement, then give a signal to a voice coil that will push the stand back into place. The linear force of the voice coil will be proportional to the thrust of the thruster based on their relative distances from the center of rotation.