Abstract: The aerodynamic characteristics of a normal hovering foil with Synthetic Jet (SJ) actuation are numerically studied in this work. An elliptic foil with ratio of 4 undergoes the imposed translation and rotation synchronously. A pair of SJs with the same frequency and strength is placed on the upper and lower surfaces of the foil. Thus, the local flow field around the foil would be influenced. At the Reynolds number of 100 and the rotating axis position of half chord, the effects of the inclined angle between the jet direction and the chord line, the phase angle between the SJs and the translation as well as the SJ location on the aerodynamic characteristics are systematically examined. Compared with the oscillating foil without SJ actuation, it is illustrated that the enhancement of mean lift force and hovering efficiency can be obtained by using the SJs with suitable working parameters. Based on the numerical analysis, it is found that the jet flow on the foil surfaces, which changes the local pressure distribution, can benefit the aerodynamic performance of the hovering foil.

Key words: normal hovering foil, translation and rotation, synthetic jet, lift enhancement