A Method for Reducing the Viscous Drag on a Submerged Surface

Background A submerged surface (e.g., a ship hull) traveling through a liquid, as well as liquid flowing through a pipeline, experience viscous drag, requiring increased power to overcome such drag.

Invention Description The solution proposes creating a pattern of small holes on a submerged surface, or in the interior surface of a pipeline, to hold small, nearly flush, bubbles in place. This approach reduces viscous drag over the entire submerged, or pipeline surface. Viscous drag reduction would result in increased speed with the same power or in reduced power for the same speed as well as reducing the hydraulic pumping power through pipelines.


Suitable for high- or low-speed liquid flows over curved surfaces Improved drag reduction in comparison to other current methods (e.g., riblets)
Reduced power required to initiate or maintain hull speed or liquid flow Reduced fuel and power generation costs


Simple to implement Surface treatment for a surface bounding a liquid flow (most easily water) to reduce viscous drag

Market Potential/Applications The market for submarines is expected to be limited to 74 new hulls, $60.5B in 2001-2011 timeframe (Aerotech, 4/02). The market made of tankers, bulkers, and containers was 48.9 million dwt in 2002 (Barry Rogiliano Salles, Paris, 2003). The U.S. annual market for power boats (categories like jet, personal watercraft, and outboard boats) is estimated at $23B and last year experienced sales of new 300,000 boats (NMMA 2003). The market for U.S. pipelines is expected to be 80 million fsw (Global Industries LTD, 3/03). Applications include: Submarines, submerged weapons (e.g., torpedoes), ships, pleasure craft, racing boats, and pipeline production.

One U.S. patent issued: 7,044,073

US 7,044,073

Inventor(s): David B. Goldstein

Type of Offer: Licensing

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