 |
 |
 |
 |
 |
 |
 |
 |
 |
 |
A: We've actually tried to keep the number of inputs down to the bare
minimum needed to get accurate predictions. Gaining accuracy
requires that information is known about many different aspects of
your boat.
Q: On my output page, my engines do not appear to be making full
power, and yet the code predicts my top speed very accurately. What
is going on here?
A: Excellent observation. Engines are rated (and dynoshops correct to)
Standard Temperature and Pressure (STP), which is generally cooler
than the weather most of us like to boat in. Run the code under the
conditions that records are set (around freezing), and see how much
power your motors make! Altitude will cause a similar reduction in your
power curve. Finally, it takes the perfect propeller and drive setup to
make the maximum speed coincide exactly with the engine's peak
power output. Any setup which is not exactly optimum will not allow
you to use every last horsepower.
Q: How long does the trial period last on my new account?
A: Your trial period includes 2000 horsepower units for you to use as you would like. After that, you'll be asked to contribute a small amount to defray the costs of keeping this service available to the public.
Q: I'm afraid of making a mistake since there are so many inputs, and
wasting my credits. How can I avoid this?
A: Not to worry. Our program screens your input to make sure that
everything was typed correctly, and values make sense. We do realize
that people dream up new errors that we could not have anticipated. If
this occurs, simply e-mail us (or we will have already noticed), and we
will refund any credit lost on a failed attempt, and modify the code so
that it doesn't happen to you or anyone else again. We are very
liberal with this policy, and are not trying to steal your money. We
hope to merely offset the development and web-hosting costs to keep
this tool available to the public!
Q: This from a customer email: "WOW, I cant believe that someone has
done this. As a mechanical engineering student, I could only imagine
all the work that went into not only writing the code but digging
through the many equations and dimensional analysis. It is well worth
the service charge. I would love to receive more information on how
this was achieved."
A: You are correct in the assumption that this was a complex
undertaking. Our Naval Architect spent about 10 years of study and
testing to get the application developed. The most challenging parts
involving the prediction of the most efficient running trim angle come
directly from his published work. The other really hard part was to
develop the supercavitating propeller module and have it adjust for
varied propeller immersion both due to user input of transom mounting
height, as well as the wave rise effect from propeller setback and
speed. The water height on the drive unit changes its drag
characteristics as well. For more info, click on the CODE page.
