Craig & Antonelli
Object disposed in a fluid flow and having a selected configuration to minimize generation of Karman's vortex street
 An object disposed in a fluid flow and defined by two surfaces, each extending along a stream line and one of said two surfaces having a reference contour. To eliminate the danger that a violent oscillation is generated due to resonance between the natural oscillation of the object and the oscillation caused by Karman's vortex which develops at the downstream end portion of the object, said downstream end portion of the object is so formed as to provide a configuration satisfying the following relations: EQU R1/TV.ltoreq.0.2 and R2/TV=6-10 where, R1 is a radius of curvature of the first portion of object's downstream end portion which is continuous with said reference surface, R2 is a radius of curvature of the second portion of object's downstream end portion extending between said first portion and the other surface, and TV is the minimum thickness of the object between said two surfaces measured from the joining point or juncture between said second portion and the other surface. 
Hitachi, Ltd.
B Y Y F
B64C Y02E Y02T F01D
inventional additional additional inventional
Mizuho Hideo Harumasa
Tanaka Ito Sato