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Top Ten Prognostications
for 2007
Miscellaneous Musings from the Technical Director
Monday, 01-JAN-2007 by Donald
MacPherson - HydroComp Technical Director
As we start the new year, I was asked to make some
predictions about the state of "marine propulsion" in 2007.
This is a bit like forecasting the weather six months in advance, but
hey, let's have a little fun. I encourage anyone with additions or
comments to this list to speak right up. (Use the Post A Comment
link below). So, here goes - my Top 10 Prognostications for 2007.
1. Propulsor CFD will still fundamentally be limited to the
R&D community. Sorry folks, we're just not there yet. Don't get me
wrong, while propulsor CFD is very useful for the analytical solution of
specific propulsion problems even now, its use for overall propulsor
design still is in its infancy. However, in the spirit of "buyers
remorse", we will see an increasing amount of press releases,
advertisements, and marketing that tries to connect the use of CFD with
product quality.
2. The number of installed inboard electric drive systems will
double - at least. I really believe that we'll see a variety of
legitimate sub-200 kW power plants installed in boats, most of which
will probably be specially designed around these systems. I get the
sense that there is a small, but growing, market segment for high
efficiency craft - yacht tenders, pleasure boats for inland lakes and
rivers, sightseeing boats. Don't be surprised to see an electric drive
tender as part of the upcoming America's Cup races in Valencia this
summer.
3. The marine engine builders will confront biodiesel in 2007 -
and ignore it. And, I'm not sure that this is necessarily a bad idea.
First, does anyone really know the life-cycle implications of using
biodiesel in marine applications? Will engines be more or less prone to
maintenance problems? Emission quality is indicated to be better, but by
how much? What is the availability of biodiesel, and does re-use of
cooking oils represent a legitimate interest for anyone? With respect to
large-scale development and distribution of biodiesel, plant-based
energy sources are having a bit of an "emperor has no clothes"
moment, as the total net energy equations for corn-based ethanol
production are being more widely reported in the general press. However,
my opinion could change in a year or so if the new "cellulose"
distillation processes are perfected, or if more consideration is given
to soybean-based biodiesel. In any case, even if all U.S. corn and
soybeans went to the production of biofuels, we still only meet a small
fraction of the total demand. Fuel reduction, not fuel alternatives,
should be our focus.
4. We will see more installations of composite propellers for
larger inboard applications this year. As more-and-more custom or
semi-custom propellers are utilized - particularly for high-performance
applications - we will see a corresponding increase in the cost of these
propellers, not only in purchase price, but also in refit or repair.
This will tend to mitigate, somewhat, one of the common arguments
against composite propellers - that they cannot easily be repitched or
repaired (if at all). I think, however, that this may be a temporary
blip. We really have not seen the longevity of composite propellers over
a typical multi-year life-cycle of a boat, and I suspect that this may
be the thing that will push people back to metal propellers.
5. Adaptive control is widely used in foil-assisted fast craft. This
year someone will develop an adaptive system for conventional
monohulls. This may take the form of a variable hull geometry (using
a dynamic stern extension, for example) or as hulls specifically
designed to exploit adaptive trimming (to optimize drag characteristics
across multiple speed regimes).
6. Pre-swirl stators. Counter-rotating propellers are out of
reach for most installations, and the next best thing is a pre-swirl
stator. This will follow the installation trend of more custom and
semi-custom propellers, and I would not be surprised to see these
stators designed and packaged with the propeller sets. I also suspect
that these will gain more use in ducted propeller applications, as well.
7. There will be a big shakeup in technical conferences in 2007.
The last 10-15 years has seen a tremendous growth in the number of
general and specialized conferences, conventions and symposia. I don't
think that you can go two weeks any time in the year and not find a
conference - and the months from September through November are the
worst. I have been seeing many of the same re-hashed papers at these
conferences, and attendance has dwindled at more than a few.
"Natural selection" works, and I will predict that some old
conferences will not return and some new conferences will not be
repeated. Attempts will be made at reaching participants with new
technologies, such as via pod-casting, but this will not find much
interest. Conferences are as much about high-quality networking with
peers, as it is publishing. In short - too much frequency, too high
cost, too many days away, too little technical value.
8. Australian swimmers will once again dominate in international
competition. Hey, swimming has water, doesn't it? And motion? Well,
water + motion = hydrodynamics. Close enough for me.
9. Hydrodynamic optimization with artificial intelligence, such
as genetic algorithms or neural nets, will not see any practical use in
2007. This is not for lack of technical capability in the tools, it is
due to a simple truth - you cannot segregate the optimization of one
aspect of a multi-disciplinary design cycle. Naval architecture is a
balance of numerous disciplines (hydrostatics, hydrodynamics,
aesthetics, layout, structure, weights, equipment). Optimization
techniques using AI or NN are often derived from a
"learning-based" approach, where trends and
"optimums" are identified from past empirical data. Optimum
points can be deceptive. A broad range of solutions may be within a
small fraction of one percent of the identified "best"
solution. So, given the typical noise in any empirical data set, is this
really "best"? What does this tell us about any new design
outside the scope of the data set? Is the one unique "best"
speed-power solution completely invalidated by structural or layout
requirements? Do the classification and regulatory agencies care what an
algorithm thinks is optimum? In my opinion, we don't need better
optimization tools, we need better analytical tools with more user
feedback so that designers and engineers can actually do what they were
trained to do.
10. And finally, the design of a 100000 kW diesel engine will be
publicized in the trade press this year. We saw a 100000 HP engine built
in 2006, and I think the 100000 kW milestone is not too far off.
Well, there you go. Let me know what you think, and we'll see how well
we did next December.
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