ESDU 93025 provides a step-by-step procedure for the geometric design of a co- or counter-rotating array of vortex generators. A criterion is first given to determine whether effective control is possible, and requires knowledge of the local Mach number just upstream of the shock and of the streamwise distance required with vortex generators for the pressure downstream of the shock to recover to its attached flow form. Guidance is then given on the selection of vane planform and aspect ratio, operating incidence, thickness, height, and fore-and-aft location. The lateral lay-out of the array is then considered. The setting of the vane to achieve the chosen operating incidence depends on the local flow direction and a method is provided of estimating that from knowledge of the freestream Mach number, the pressure coefficient and the local sweep of the isobar. A flowchart guides the user through the design procedure.