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:
Nov. 27, 2001
Filed:
May. 24, 1999
Yoshiaki Takahashi, Tokyo, JP;
Yuki Yoshida, Kawasaki, JP;
Hiroharu Kato, Matsudo-shi, Chiba-ken, JP;
Other;
Abstract
A method is provided for analyzing the effects of bubbles on skin-friction reduction in a ship cruising in a bubbly flow field. A shear stress decrement &tgr;,produced by a bubble in a flow field is obtained in a high frequency band region, in which a product of a bubble time-constant T and a turbulence frequency &ohgr;,in a flow field is sufficiently greater than 1, based on a resistive force &Dgr;R,acting on a bubble derived from the bubble movements in a fluid flow direction along a ship surface and in a direction at right angles to a ship wall surface. Assuming that the shear stress a decrement is generated by a decrease in a gas mixing length, an expression for the operative wall constant &kgr;,for bubbly flow including a parametric bubble diameter d,is derived. Based on an expression relating the operative wall constant &kgr;,and a local friction factor C,in bubbly flow, and an expression relating the normal wall constant &kgr; in non-bubbly flow and a local friction factor C,in non-bubbly flow, an analytical solution is obtained for a skin-friction ratio C,/C,.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile