# Need help for "Solar powered model calculations"

Discussion in 'Hydrodynamics and Aerodynamics' started by samar87, Mar 9, 2016.

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### samar87New Member

Hi

I am a last year engineering student and I need help for my research.
I want to run a model ship on solar powered energy .
The main target is to transport people so it must carry as much weight as it can. I was looking for a catamaran model but I didn't find any at online stores.
So now considering a mono hull ship, I don't know what are the calculations that must be done to know the most appropriate Length and breadth and hull form.
I need some help with the start as I'm really confused.

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### JoakemJunior Member

To start....

Hello Samar,

Maybe something like this......
1. Get the design requirements well defined.
(Maybe; number of passengers, daily travel distance, seastate/waterdepth)
2. Do an internet search to similar passenger ferries, similar routes.
3. Establish their daily energy consumption.
4. Calculate number of batteries on board.
5. Calculate size of the solar farm onshore.

Enjoy!!

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### gonzoSenior Member

Your first calculation should be available power. That will be the integral of solar radiation. Use average days of sunshine, minus a reasonable percentage. You will have to also integrate for the change in the angle of incidence through the day. This will be your limiting factor. The rest of the design will evolve from it.

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### SamSamSenior Member

I find this thread worrisome. A future 'engineer' in his last year of education and training needing help to design a boat to carry as many people as possible because he doesn't have a clue about the most basic calculations needed.

I guess someone could give him a primer on displacement, someone else could try and inform him on the futility of solar power, but maybe it would be best to start with the basics, such as how much it sucks when lots of people drown because of engineering incompetence.

I could be wrong. I hope I am, but I don't think so. To know so little in the final year of any sort of training is dismal. I can't see where offering any engineering advice at all is a positive. This guy needs to fail to safeguard others.

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### JoakemJunior Member

Many types of engineering.
Someone with a specialty in electrical design and solar, trying to apply his/her dedicated knowledge onto a different field.
And asking more knowledgable people for some pointers.
Does not seem strange and uncommon to me.

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I assume, correct me if I am wrong, that your engineering is not naval architecture, thus some other engineering discipline?

Assuming this....

A boat floats and floats on a certain draft. This provides the displacement. A hull is designed to carry THAT displacement. The design of the hull is affected if the required speed falls under or over a certain Froude number (hydrodynamic term).

The power required to achieve THAT speed, is dictated by the above.

Thus, you first need to establish what much power. And by that, using the equipment that you are going to use for your model, how much power can you get from it? Then weigh the equipment.

From this you can quickly establish what size of model and thus how fast you may be able to go. Until you can confirm the above...impossible to say.

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### gonzoSenior Member

That is usual when you can specify the power. However, solar power will be the limiting factor because there is a maximum available per surface unit.

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### samar87New Member

Thanks

I must thank you. You really helped me soooooooo much.
Thanks a lot.

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### samar87New Member

Thanks

I have done that , thank you very much.
Unfortunately, here there is few shops that sell solar panels for such models of small size ..
Do you know a good online shop?

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### samar87New Member

Thanks for your reply, I have done a research before on a catamaran ship, but it's the first time to test a model. I wanted to buy a catamaran model from the internet but I didn't find any. The best kind I found was that one
http://www.dumasproducts.com/product_info.php?products_id=356
But it's the first time to deal with this company , so I decided to make my calculations and test it on Max surf first.

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### gonzoSenior Member

Multihulls are good for solar power because of their large deck areas. However, in general have less cargo capacity than a monohull may. Google "solar panels for sale egypt" and you will get over 500,000 results.

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### Jim CaldwellSenior Member

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### gonzoSenior Member

For a small model, you can carve the hulls out of foam and paint them with water based acrylic.

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