Multiscale-Multiphysics Modeling and Optimization of Electrospray Array Ion Sources

A multiscale and multiphysics workflow for electrospray ion source modeling has been developed to investigate the performance and plume divergence sensitivity of integrated thruster arrays. Electrohydrodynamic simulations inform current emission profiles, gridless [Formula: see text]-body methods model single-emitter acceleration zones, and particle-in-cell models combine these into a complete plume model. This workflow investigates the design space for single emitters with regard to tip–extractor distance and operating potential, then propagates these results to the array scale to evaluate specific impulse, beam divergence, and thrust density. Regression models developed from 54 array simulations predict beam divergence and thrust density as functions of operating voltage, emitter spacing, and array size, achieving [Formula: see text] values of 0.9933 and 0.9777, respectively. These models reveal that divergence scales linearly with the number of emitter rows and sublinearly with beam current, while thrust density follows a quadratic voltage dependence with an effective potential penalty for larger arrays. A restricted optimization problem is formulated to maximize propulsive performance subject to a beam divergence constraint. For porous emitter architectures, the optimal configuration maximizes acceleration potential first, then increases packing density until the divergence limit is reached.