Surface-processed structure, surface-processed sheet, and propeller fan

A surface-processed structure comprising:

• a plurality of blocks arranged side by side in a first direction parallel to a target surface and a second direction orthogonal to the first direction, the plurality of blocks being three-dimensional objects arranged on the target surface, the target surface being a surface of a target object,
• wherein each of the plurality of blocks includes an inclined surface extending from upstream to downstream in the first direction with a distance from the target surface gradually increasing,
• a plurality of the inclined surfaces of the plurality of the corresponding blocks are arranged side by side on a line extending in the first direction,
• each of the plurality of blocks includes a plurality of fine grooves provided on the inclined surface,
• the plurality of fine grooves are spaced apart from each other, are arranged side by side in the second direction, and extend from upstream to downstream in the first direction,
• a clearance having a groove shape and extending in the first direction is formed between two blocks of the plurality of blocks adjacent to each other in the second direction,
• a width of each of the plurality of fine grooves in the second direction is narrower than a width of the clearance in the second direction,
• the plurality of blocks are arranged in such a manner that the clearance constitutes a fluid flow path extending in the first direction, and
• sets of the plurality of fine grooves each provided on the inclined surface and a plurality of the fluid flow paths are arranged alternately along the second direction.