US 12,214,863 B2
Riblet structure and object
Mitsuru Kurita, Tokyo (JP); Hiroyuki Abe, Tokyo (JP); Hidetoshi Iijima, Tokyo (JP); and Seigo Koga, Tokyo (JP)
Assigned to Japan Aerospace Exploration Agency, Tokyo (JP)
Appl. No. 18/245,562
Filed by JAPAN AEROSPACE EXPLORATION AGENCY, Tokyo (JP)
PCT Filed Sep. 22, 2021, PCT No. PCT/JP2021/034773
§ 371(c)(1), (2) Date Mar. 16, 2023,
PCT Pub. No. WO2022/085357, PCT Pub. Date Apr. 28, 2022.
Claims priority of application No. 2020-175216 (JP), filed on Oct. 19, 2020.
Prior Publication US 2023/0365251 A1, Nov. 16, 2023
Int. Cl. B64C 21/10 (2006.01); F15D 1/00 (2006.01); F15D 1/12 (2006.01)
CPC B64C 21/10 (2013.01) [F15D 1/004 (2013.01); F15D 1/12 (2013.01); B64C 2230/26 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A riblet structure, comprising:
a plurality of wave-shaped riblets being arranged in parallel in a first direction on a surface thereof,
wherein an amplitude direction of waves of the wave-shaped riblets is the same as the first direction,
wherein each of the riblets has a smaller peak height from the surface as a first angle formed between a ridge line of the riblet and a second direction becomes larger, the second direction being an advance direction of waves of the wave-shaped riblets,
wherein a width between peak bases, of wave-shaped riblets of the plurality of wave-shaped riblets that are adjacent to each other, in the first direction becomes smaller as the first angle becomes larger, and
wherein a second angle formed between a slope of a peak of the riblet and the surface at the peak base or a curvature at the peak base is identical at any position in a cross-sectional shape in the first direction.