The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 04, 1990
Filed:
Jul. 05, 1989
Applicant:
Inventors:
Mitsutoshi Miura, Tokyo, JP;
Hiroharu Kato, Chiba, JP;
Assignee:
NKK Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F01D / ;
U.S. Cl.
CPC ...
416237 ; 416235 ;
Abstract
A low-resistant hydrofoil comprises at least one concave step arranged backwardly in the direction of a chord of blade of the hydrofoil in parallel with the leading edge of the hydrofoil to form a lamellar cavitation layer on the negative pressure surface of the hydrofoil moving under water. The concave step has depth .DELTA.t and .DELTA.t/C is more than 0.001 and less than 0.01, being a chord length. The concave step is 0<x.sub.1 /C<0.1, x.sub.1 being a distance from the leading edge of said hydrofoil and C being a chord length.