Influences of Geometric Parameters on the Propulsion Performance of Three-Dimensional Bionic Motion Wings

To study the influence of geometric parameters on the propulsion performance of three-dimensional bionic motion wings, a general large-scale solver based on IB-LBM algorithm for Tianhe-II supercomputer is developed. To implement this process, the immersed boundary method is used to construct a force function on the surface of the wing. Then the force function is spread to the neighbor fluid mesh with interpolation function. The lattice Boltzmann method is used to perform fluid computation and update the velocity field. Four different wings, i.e., ellipsoidal wing, plate wing, NACA0012 wing and cuboid wing, are investigated to explore how the geometric shapes of the wings influence the thrust coefficient and vortex structure. The numerical results show that the vortex induced by the ellipsoidal wing is fully structured and close to the surface of the wing, so its propulsion performance is best. The vortex structures of NACA0012 wing and plate wing are similar, and hence have similar propulsion performance. The vortex structure of cuboid wing, however, is small and far from the wing surface, leading to a worst propulsion performance. So, in design of bionic airplane, the cuboid wing should be excluded. Although the performance of ellipsoidal wing is best, it requires a high-quality mass distribution in connection parts, so the plate wing would be a proper choice as a result of tradeoff.