Theoretical Methods

This chapter briefly describes the theoretical approaches commonly used to gain insight into the tip streaming phenomenon. These approaches allow one to solve or at least obtain information from the governing equations presented in the previous chapter. We discuss the main characteristics of direct numerical simulations and global and local stability analyses. The differences between these two last approaches are explained to emphasize the importance of the global stability analysis for tip streaming. Concepts such as global modes, asymptotic stability, and short-term response are also discussed. The temporal and spatiotemporal local stability analyses provide information on the behavior of the jets emitted in the microjetting mode of the tip streaming configurations. This chapter closes with some results obtained from those analyses and directly related to those configurations, including the effects of electric fields, surfactants, and viscoelasticity.