Electromagnetic control of charged particulate spray systems—Models for planning the spray-gun operations

• Derived criteria to control charged particulate sprays using electromagnetic fields.
• Such criteria can be used in physically based computer simulations for such sprays.
• Coupled multi-physics aspects of such modifications are presented.
• These aspects are critical for identifying core issues to guide future research.

Charged particulate spray systems are common in many industrial and manufacturing processes. Using externally applied electromagnetic fields–the dynamics of these particulate sprays can be altered to achieve improved functionality and access to spray-sites that are hard to reach. With such an alteration the spray-particulate dynamics can become non-intuitive–thereby motivating a physically based modeling strategy to plan the spray-gun operations and translate this into the actual spray deposition on the target surface. In this paper we use the dynamics of charged particles to construct a set of simple geometric arguments for the identification of the mapping between the spray-gun trajectory (on its plane of traversal) and the spray-deposit location (on the plane of the target-surface). The parametric dependence of the mapping on spray-gun operation parameters (comprising nozzle velocity and trajectory) and external magnetic fields (comprising field strength and the region of applied field) is discussed. The role of such arguments in constructing appropriate computer simulation frameworks is then illustrated through an example of a discrete element simulation. Sensitivity to process parameters like particulate size and spray-gas velocity are also characterized for a given applied field.