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Open AccessArticle

Thrust Augmentation of Micro-Resistojets by Steady Micro-Jet Blowing into Planar Micro-Nozzle

by Donato Fontanarosa, Maria Grazia De Giorgi and Antonio Ficarella

Appl. Sci. 2021, 11(13), 5821; https://doi.org/10.3390/app11135821 - 23 Jun 2021

Cited by 2 | Viewed by 2171

The present work investigates the impact of steady micro-jet blowing on the performance of a planar micro-nozzle designed for both liquid micro-thrusters and nitrogen cold-gas micro-resistojets. Two micro-injectors have been placed into the divergent region along the sidewalls, injecting a secondary flow of propellant perpendicularly to the wall where they have been located. The micro-jet actuator configuration is characterized by the dimensionless momentum coefficient c_μ. The best performance improvement is retrieved at the maximum c_μ for both water vapor (

Δ %_{T, j e t}

= +22.6% and

Δ %_{I s p, T j e t}

= +2.9% at c_μ = 0.168) and nitrogen gaseous flows (

Δ %_{T, j e t}

= +36.1% and

Δ %_{I s p, T j e t}

= +9.1% at c_μ = 0.297). The fields of the Mach number and the Schlieren computations, in combination with the streamline visualization, reveal the formation of two vortical structures in the proximity of secondary jets, which energize the core flow and enhance the expansion process downstream secondary jets. The compressible momentum thickness along the width-wise direction θ_xy in presence of secondary injection reduces as a function of c_μ. In particular, it becomes smaller than the one computed for the baseline configuration at c_μ > 0.1, decreasing up to about and -57% for the water vapor flow at c_μ = 0.168, and -64% for the nitrogen gaseous flow at c_μ = 0.297. Full article

(This article belongs to the Special Issue Micro Power Technologies for Air and Space Vehicles)

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30 pages, 889 KiB

Open AccessReview

An Overview of Cube-Satellite Propulsion Technologies and Trends

by Akshay Reddy Tummala and Atri Dutta

Aerospace 2017, 4(4), 58; https://doi.org/10.3390/aerospace4040058 - 9 Dec 2017

Cited by 155 | Viewed by 30123

Abstract

CubeSats provide a cost effective means to perform scientific and technological studies in space. Due to their affordability, CubeSat technologies have been diversely studied and developed by educational institutions, companies and space organizations all over the world. The CubeSat technology that is surveyed in this paper is the propulsion system. A propulsion system is the primary mobility device of a spacecraft and helps with orbit modifications and attitude control. This paper provides an overview of micro-propulsion technologies that have been developed or are currently being developed for CubeSats. Some of the micro-propulsion technologies listed have also flown as secondary propulsion systems on larger spacecraft. Operating principles and key design considerations for each class of propulsion system are outlined. Finally, the performance factors of micro-propulsion systems have been summarized in terms of: first, a comparison of thrust and specific impulse for all propulsion systems; second, a comparison of power and specific impulse, as also thrust-to-power ratio and specific impulse for electric propulsion systems. Full article

(This article belongs to the Special Issue Micro-Propulsion Systems and Components for Small Spacecraft—Current Trends, Innovations and Challenges)

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