Waterjet Impeller
North American Marine Jet Inc. (NAMJ), Benton, Arkansas manufactures
waterjet propulsion systems for such craft as fishing boats,
fire boats, houseboats and excursion boats. The company's newest
line of marine jets incorporates NASA technology that, company
president Leonard Hill expects, will make NAMJ significantly
more competitive in a market long dominated by European and Pacific-area
manufacturers.
Leonard Hill of North American Marine Jet and Dinah Higgins
of Marshall Space Flight Center display an impeller blade made
by advanced rapid prototyping techniques.
Looking for ways to match the technological advances of his
competitors, Hill attended a propulsion symposium at Marshall
Space Flight Center (MSFC) and learned that technological assistance
was available to him under NASA's Technology Transfer & Commercialization
Program.
Hill and his design staff sought advice from MSFC as to the
efficacy of a proposed design for a new impeller, planned as
the heart of a new line of marine jets. The Computational Fluid
Dynamics (CFD) branch of MSFC's Structure and Dynamics Laboratory
used advanced CFD techniques, including creation of a three-dimensional
computer model of the impeller, to analyze the design and concluded
that it would not provide the desired propulsive performance.
With Marshall input, NAMJ modified the design and a second
analysis indicated that the redesigned impeller would meet or
exceed NAMJ's specifications. MSFC then used a 3D computer model
of the modified system to make a solid polycarbonate model of
it. NAMJ was then able to have a metal prototype cast directly
from a ceramic mold made directly from the polycarbonate.
The NAMJ experience not only exemplifies the kind of NASA
assistance available to industry, it is also an example of the
important time saving possible through adoption of MSFC's rapid
prototyping technology. Under the center's Rapid Prototyping
Program, which involves the direct production in three dimensions
of a prototype from a computer-aided design, MSFC is developing
technologies designed to enable sharp time/cost reductions in
manufacturer's design-to-product development cycles. Ordinarily,
NAMJ would have spent weeks creating a solid model of the impeller
in a laborious, costly multistep process. The work of MSFC's
Materials and Processes Laboratory and the use of rapid prototyping
techniques allowed avoidance of many time-consuming and costly
steps in creating the impeller model.
|
