US Patent 10060271 Fan airfoil shrouds with area ruling in the shrouds

A shrouded airfoil may have a suction surface and a pressure surface. An at least first suction surface shroud may be disposed on the suction surface and an at least first pressure surface shroud may be disposed on the pressure surface. The at least first suction surface shroud may include a first and second contoured surface and a first mating face. The first contoured surface may have a first substantially concave portion and a first substantially convex portion. The second contoured surface may have a second substantially concave portion and a second substantially convex portion. The at least first pressure surface shroud may include a third and fourth contoured surface and a second mating face. The third contoured surface may have a third substantially concave portion and a third substantially convex portion. The fourth contoured surface may have a fourth substantially concave portion and a fourth substantially convex portion.