A validated numerical simulation modeling of flapped wing wake is carried out by using RANS discretion. The flapped wing wake region is divided into three regions with significant different dynamic features. Three regions including co-rotation field

merging field and axial symmetry far field are induced. A non dimensional parameter of vortex interval is used to describe above regions. The Reynolds number

vortex interval

flap angle are used as control variables to change ratio of circulation of flap vortex and tip vortex. Reynolds effect is found as prolonged co-rotation field and enhanced rotation motion in wake. Decreased vortices interval leads an accelerated merging in near field but a limited dimension of resulted vortex. Small flap angle leads a weak flap vortex. The dominated tip vortex stretches and filament flap vortex in free share layer. The merging process is totally changed. The tip vortex trajectory does not expand. Reynolds number effect is the enhancement of induction in tip vortices merge. Induction of vortices with low intensity is not obvious in the wake.