This review paper provides an overview of the governing equations of electrohydrodynamics pertaining to dielectric liquid atomization. The majority of the paper concentrates on the governing equations of electrohydrodynamic (EHD) flow and general averaged forms and their relevance to the study of charge injection atomizers. These equations are nondimensionalized and will bring to the forefront relevant quantities that define the electroconvective problem. A time-scale based method and traditional engineering method of nondimensionalization highlight values of key numbers for several specific charge injection atomizer concepts. Finally, an overview of EHD turbulence literature is provided along with a statement of the Reynolds-averaged governing equations allowing for discussion of the unclosed terms appearing and their probable significance.