Dual-Mode Propellant Properties and Performance Analysis of Energetic Ionic Liquids
Imidazole-based energetic ionic liquids capable of dual-mode chemical monopropellant or bipropellant and electric electrospray rocket propulsion are investigated. A literature review of ionic liquid physical properties is conducted to determine an initial set of ionic liquids that show favorable physical properties for both modes, followed by numerical and analytical performance simulations. Of the ionic liquids considered in this study, [Bmim][dca], [Bmim][NO₃], and [Emim][EtSO₄] meet or exceed the storability properties of hydrazine and their electrochemical proper ties are comparable to [Emim][Im], the current state-of-the-art electrospray propellant. Simulations show that these liquids do not perform well as chemical monopropellants, having 10-22% lower specific impulse due to their lack of oxidizing species. The ionic liquids show acceptable bipropellant performance when burned with standard oxidizers, having specific impulse 6-12% lower than monomethylhydrazine and nitrogen tetroxide combination. Considering these ionic liquids as a fuel component in a binary monopropellant mixture with hydroxyl ammonium nitrate shows 1-3% improved specific impulse over some green monopropellants, while retaining a higher molecular weight, reducing the number of electrospray emitters required to produce a given thrust level. More generally, ionic liquids with oxidizing anions perform well as chemical monopropellants while retaining high molecular weight desirable for electrospray propulsion missions
S. P. Berg and J. L. Rovey, "Dual-Mode Propellant Properties and Performance Analysis of Energetic Ionic Liquids," 50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, American Institute of Aeronautics and Astronautics (AIAA), Jan 2012.
The definitive version is available at http://dx.doi.org/10.2514/6.2012-975
50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition
Mechanical and Aerospace Engineering
Article - Conference proceedings
© 2012 American Institute of Aeronautics and Astronautics (AIAA), All rights reserved.