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and then to eheck the strength ofthe propeller design. The detailed steps ofCFD and FEA
for a propeller design arc listed in Chapter 3.
2.6 Review of Propeller Fabrication
Following the design validation through CAE, a real prototype part is nceded to be
fabricated for testing. With the development ofcomputer aided engineering (CAE)
softwarc, some software applications are available for propeller simulation, which can
predict the results ofa propeller test and be a convenient way for engineers to speed up
the design ofthe final pmpcller. Because simulation does not reflect all the aspects ofthe
real world accurately, simulation models arc designed and used with the goal of
approximating the testing process, but, can't completely replace the testing process.
Physical prototype testing is used to increase to an acceptable level the confidence that
the simulation results are correct for the real component [29]. For this reason, propellers
need to be fabricated for testing after the simulation. 111ere are generally three methods of
propeller fabrication: Casting and Computed Numerically Control (CNC) machining
technology are the traditional methods. In the latc 1980s, rapid prototyping (RP) was
introduced and by thc late 90's it was used as a low cost and fast process for physical
prototype fabrication.
2.6.1 Traditional Fabrication Processes
Casting is a manufacturing process which involves pouring liquid material into a mould
designed with thc desired shape, and then allowing to solidify. The solidified component
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