Instability Modes and Scaling Analysis During Electro-Hydro-Dynamic-Atomization: Theoretical and Experimental Study

The electro-hydro-dynamic-atomization (EHDA) is a well-established technology with numerous micro/nanoparticle fabrication applications. However, a consistent method for explaining the physics behind the process has yet to be established. The present study aims to report a comprehensive non-dimensional analysis to develop a correlation between different process parameters. The dimensionless numbers derived from Buckingham’s pi theorem match well with those derived from the Navier–Stokes equation, establishing the forces involved in EHDA. Flow instability modes during the EHDA process are experimentally visualized using the flow visualization technique and characterized using a microscope. The instability modes are described using derived non-dimension numbers, and results closely align with Ganan-Calvo’s findings. Derived scaling for the current is in good agreement with Ganan-Calvo (1997), which complies with the condition if δ_μ × (Q/Qo)^1/3 >  > 1, then I/Io = 11 × (Q/Qo)^1/4 -5. Moreover, the ratio of ln (Ehd)/ ln (Md) in cone jet mode is found to be ≈2, irrespective of fluids.