Large scale simulations of colloid thrusters: Coarse graining strategies

John W. Daily, Michael Matthew Micci

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Work is reported here on developing coarse-graining strategies for carrying out large-scale molecular dynamics simulations of colloid thruster emitters. Colloidal thruster technology is based on the electrostatic acceleration of small droplets and/or ions that are generated by feeding a conducting fluid through a small capillary and applying a large acceleration potential between the capillary and an extraction electrode. A wide range of length and time scales are encountered and modeling the entire flow field using continuum methods is a formidable task that has not yet been achieved, in particular at the tip of the Taylor cone. The advantage of molecular dynamics simulations is that all the pertinent physics can be incorporated in reasonably straightforward fashion. However, modern propellants are most frequently ionic liquids where one or both of the ions are quite large. Thus, it behooves the modeler to attempt to reduce the number of particles in the simulation to gain computational speed. Coarse-graining involves representing a large molecular ion with a smaller number of atomic cluster sites, where the potential energy parameters for each site have been optimized to reasonably reproduce the total potential energy field of the original molecular ion. Measures of success include parameters such as the drift velocities of individual ions, electrical conductivity, surface tension and wettability.

Original languageEnglish (US)
Title of host publicationCollection of Technical Papers - 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference
Number of pages17
StatePublished - 2007
Event43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference - Cincinnati, OH, United States
Duration: Jul 8 2007Jul 11 2007


Other43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference
CountryUnited States
CityCincinnati, OH

All Science Journal Classification (ASJC) codes

  • Space and Planetary Science

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