Analysis of Propulsive Performance and Flow Field Structures for Dual Symmetry-flapping Airfoils in Parallel Configuration

Dual symmetry-flapping airfoils in parallel configuration have superior propulsive performance.The unsteady flow fields around flapping airfoils are simulated by solving the 2D viscous incompressible N-S equations based on the immersed boundary method in this paper.The factors that influence propulsive performance and flow field structures, such as plunging amplitude, plunging reduced frequency, distance between the dual airfoils and angle of attack of airfoils, are studied by simulating the unsteady flow around the dual symmetry-flapping NACA0012 airfoils in parallel configuration.One of dual symmetry-flapping airfoils could achieve a higher thrust force、stronger vortexes and jet flows than the single flapping airfoil while the flapping parameters remained the same.