Numerical Investigation on the Flow Field Produced by Oscillating Foils

Abstract

Abstract. In present manuscript, the flow field produced by oscillating foils in a duct were under investigation numerically. The flow field was considered as an incompressible laminar transient flow. In this paper, the oscillating frequencies were 2, 4 and 6 Hz; the span angles of the foil were 30˚, 60˚, 90˚, 120˚, and 150˚, respectively. The flow field produced by a particular oscillating pattern (fast forward slow backward, FFSB) has been made in comparison with that by the sinusoidal oscillating pattern. The flow field produced by dual oscillating foils was also analysed. Two foils oscillated in the same direction (in-phase) and in the opposite direction (counter-phase) were studied as well. Commercial software ANSYS-FLUENT was employed for the 2D numerical simulation. A moving grid technique was utilized in the analysis. Results present the flow average velocity increases as the oscillating frequency increases. It is also shown that the flow average velocity with span angle of 120˚ is the largest among these cases. In addition, the flow average velocity with dual foils is better than that with a single foil.