RIDGE STRUCTURE, WING, DESIGN METHOD OF RIDGE STRUCTURE, AND DESIGN PROGRAM FOR THE SAME

The ridge structure has ridge elements provided on a top face of a leading edge region directly downstream of a leading edge, which is a laminar flow region of a wing having a swept-back angle relative to a mainstream and provided with a leading edge, and extending in parallel toward downstream of the mainstream. When an angle of a ridgeline connecting vertexes of the ridge elements in an extending direction of the ridge elements relative to x direction is OR, an angle of a flow line of a boundary layer external edge of the mainstream relative to the x direction is θe, and an angle of a wavefront of stationary cross-flow instability, which is a mode in which a stationary disturbance amplifies inside a boundary layer of the surface and appears as a stationary vortex row, relative to the x direction is θcf, θR is between θe and θcf.