Characterization of a High Thrust, Pressure-Fed Electrospray Thruster for Precision Attitude Control Applications

Demmons, Nathaniel; Wood, Zack; Alvarez, Nereo

doi:10.2514/6.2019-3817

Cited by 8 publications

(3 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this section, the wedge geometry of emitters will be considered. This geometry is less popular than the cone geometry, but has seen implementation in both research groups (Bretti, 2020;Chen, Chen, & Zhou, 2020; and industry (Demmons et al, 2019). In contrast to cone-shaped emitters, wedge-shaped emitters have a linear extraction surface where the applied electric field is strong and ideally uniform.…”

Section: Wedge Geometrymentioning

confidence: 99%

“…In all applications of electrospray propulsion, dynamic events are unavoidable. When used for precision control, electrospray thrusters are continuously varied to provide the required thrust on a spacecraft (Demmons, Wood, & Alvarez, 2019). Electrospray thrusters have also been operated under pulsewidth-modulated (PWM) control, in which changes in the operating condition of the device are rapid and drastic (Courtney, Alvarez, & Demmons, 2018).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Transient Flow in Porous Electrosprays

Wright

Wirz

2022

Preprint

View full text Add to dashboard Cite

Porous ionic electrospray emitters have received significant interest for space propulsion due to their performance and operational simplicity. We have developed a diffusion equation for describing the transient flow response in a porous electrospray emitter, which allows for the prediction of the settling time for flow in the porous emitter. This equation accounts for both the change in liquid storage at exposed pores on the emitter with pressure, and viscous diffusion through Darcy's law. Transient flow solutions are provided for the most common emitter topologies: pillar, cone, and wedge. Transient flow solutions describe the settling time and magnitude of current overshoot from porous electrosprays. Comparing diffusion of pressure to the onset delay model for electrospray emission shows that diffusion is most relevant at higher voltages and when a porous reservoir is used. Accounting for multiple emission sites on the wedge geometry shows that emission sites settle in proportion to emission site spacing to the power -1.74. Applying the diffusion equation to published results shows good agreement between analytical predictions and experimental data.

show abstract

Section: Wedge Geometrymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Transient Flow in Porous Electrosprays

Wright

Wirz

2022

Preprint

View full text Add to dashboard Cite

show abstract

“…An electrically forced jet forms in response to the field singularity, extracting fluid from the meniscus [27]. The conical shape of the meniscus may be sustained by feeding fluid to the emission site, often through use of a capillary tube and an active feed system, as is the case in Busek's Colloid MicroThruster System (CMTS) [28,29].…”

Section: Electrospray Emission Modesmentioning

confidence: 99%

Emission Modes in Electrospray Thrusters Operating with High Conductivity Ionic Liquids

Uchizono¹,

Collins²,

Thuppul³

et al. 2020

Aerospace

View full text Add to dashboard Cite

Electrospray thruster life and mission performance are strongly influenced by grid impingement, the extent of which can be correlated with emission modes that occur at steady-state extraction voltages, and thruster command transients. Most notably, we experimentally observed skewed cone-jet emission during steady-state electrospray thruster operation, which leads to the definition of an additional grid impingement mechanism that we termed “tilted emission”. Long distance microscopy was used in conjunction with high speed videography to observe the emission site of an electrospray thruster operating with an ionic liquid propellant (EMI-Im). During steady-state thruster operation, no unsteady electrohydrodynamic emission modes were observed, though the conical meniscus exhibited steady off-axis tilt of up to 15°. Cone tilt angle was independent over a wide range of flow rates but proved strongly dependent on extraction voltage. For the geometry and propellant used, the optimal extraction voltage was near 1.6 kV. A second experiment characterized transient emission behavior by observing startup and shutdown of the thruster via flow or voltage. Three of the four possible startup and shutdown procedures transition to quiescence within ∼475 μs, with no observed unsteady modes. However, during voltage-induced thruster startup, unsteady electrohydrodynamic modes were observed.

show abstract

Transient Flow in Porous Electrosprays

Wright,

Wirz

2024

Transp Porous Med

View full text Add to dashboard Cite

Characterization of a High Thrust, Pressure-Fed Electrospray Thruster for Precision Attitude Control Applications

Cited by 8 publications

References 1 publication

Transient Flow in Porous Electrosprays

Transient Flow in Porous Electrosprays

Emission Modes in Electrospray Thrusters Operating with High Conductivity Ionic Liquids

Transient Flow in Porous Electrosprays

Contact Info

Product

Resources

About