Kinetic modelling of eletrospray systems using particle in cell method

Budaraju, Siddharth

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https://hdl.handle.net/2142/113793 Copy

Description

Title

Kinetic modelling of eletrospray systems using particle in cell method

Author(s)

Budaraju, Siddharth

Issue Date

2021-07-21

Director of Research (if dissertation) or Advisor (if thesis)

Levin, Deborah

Department of Study

Aerospace Engineering

Discipline

Aerospace Engineering

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

M.S.

Degree Level

Thesis

Keyword(s)

Electrospray propulsion, Particle-in-cell approach, Lagrangian frame, Eulerian mesh

Abstract

Electrospray propulsion facilitating ionic liquids is a recent booming application used by satellites applications for micro-thrust purposes. With the benefit of numerical methods, it is possible to model the expansion of the charged ions emanating from the ionic liquid. Particle-in-cell (PIC) approach is one such numerical method that can be used for high-fidelity plasma modelling, where individual charged particles in a Lagrangian frame are tracked continuously, while the density and currents are computed on Eulerian mesh points. In this thesis, the PIC technique was used to model the plasma plume expansion for micrometers and millimeter domains. The number density and timestep used in the simulations for the millimeter domain cases, calculated from the inlet area, were 7.3 x 10^(18) #/m^3 and 4.5 x 10^( −12) s. The plume characteristics showed striations that formed due to the large radial electric fields generated near the emitter inlet. To resolve the electric field better, an electric field correction term was implemented, where the field was redefined with the first order gradient term along with the standard centroid field value of each cell. The domain was then refined into constant, linear and exponential grids to study the influence of the refinement near the emitter region on the striations forming in the domain. The correction implementation was found to benefit in reducing the striations and showed maximum significant for constant refinement grid case, where the divergence gap formed near the acceleration region decreased greatly. The linear case showed slight improvement, followed by the exponential case having the finest grid near the emitter inlet showed no significant change with correction implementation.

Graduation Semester

2021-12

Type of Resource

Thesis

Permalink

http://hdl.handle.net/2142/113793

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Copyright 2021 Budaraju Siddharth

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