The Propulsor is the Drive.
You will note the use of the term“Propulsor” rather than“propeller”.
It is important to take a moment and mention the implications of UUV Propulsor manufacture.
On the other side of the Propulsor is the Drive, which will typically be an electric motor.
It is generally the influence
of external design drivers that can make successful UUV Propulsor design so challenging.
Each of these is evaluated as part of our Propulsor design, with mitigation as needed by changes to a blade's outline
and its camber-pitch distribution.
This is to reinforce the concept that a nozzle and propeller(as found on most UUVs and often called the vehicle's“thruster”)
is an interactive unit, the Propulsor.
In all UUV Propulsor design projects,
one universal objective is to develop a geometry that generates the highest thrust-to-power ratio(its efficiency), which we achieve using well-established practices.
During the build by Lamprell shipyard in Dubai, the three motors that
came from another supplier were augmented with The Switch's delivery of three 3,800 kW Propulsor drives;
Therefore, many Propulsor design projects start with prediction of a vehicle's drag
and hull-Propulsor coefficients(wake fraction and thrust deduction) using the NavCad® software for hydrodynamic and propulsion system simulation.
MacPherson said he has also observed a trend away from a
single design point where one Propulsor is specified for a single operating scenario,
with optimum performance at just one condition.
While this may be attractive from a financial and deliverability standpoint, we must take care that performance is not compromised by inappropriate surface
texture(which can have a huge influence for Propulsor of the small size found on most UUVs), fatigue strength failures.