Gernal Submarine and Navy Questions.

[RedDevilCG]

Just thought that I would throw this topic up. I think that the more people know about how things work in real life (even if we are only guessing), the better they will be able to both appreciate DW, and add constructive comments to improve gameplay.

Post up you're questions, and hopefully someone out there who knows the answer will reply to it.

Some rules to prevent clutter:

Questions:
1) Try to make your questions clear. You don't have to pose long questions, but try to tell us what you understand, and what is getting you "stuck". A good example would be: "what's the deal with UUV "Gliders"? Its not like "lift" is a problem in water like it is in air. Why would a "glider" in water have increased range?"
2) Try to keep your questions to 1-3 max at a time. If you post a huge page of every question under the sun, people will lose interest in even reading this thread. Many questions at once will kill the flow.
3) Focus on questions that are DW, Navy, Airforce, and physics etc.. to try to prevent this post from going too far off topic and being moved.

Answers:
1) Make sure to quote the question you are answering.
2) Post only if you know the answer (absolute things, such as explaining physics, math etc...), or if you have good qualitative answers ("In my experience, this sub performs like such and such"). Posting to say "I don't know" will not be needed Bonus points if you can throw up a URL link to demonstrate visually what you are explaining, and for adding references if you quote from a book!
3) Don't answer a question that has already been answered, unless you have more to add. Basically we don't need double posts saying the same thing. If you have something to add, try and quote the question along with the relevent piece of the explanation you want to expand upon.
4) Like questions, try to keep the answers brief, and simple.

Sound Good?

[RedDevilCG]

To start things off, I am pasting a post made by Deathblow here: http://www.subsim.com/phpBB/viewtopi...=443476#443476

I am breaking my rule about only posting the question you are answering, but this is just to a list up to have people start answering while we wait for others to post up questions.

So what's a good source for technical opinions? I have a ton of technical questions that I can never seem to find any good discussions on. Like...

.. why do you think the VA and SW chose to mount its towed array on fins instead of thru aft control surfaces like on the LA and Ohio? Seems like it would increase drag to me, but am I mistaken.

... why do you think the VA went back to the 4 horizontal + 12 VLS tubes instead of the SW 8 horizontal tubes? Seems like 8 horizontal tubes offers more payload flexibility, with only a minor loss in the rate of missile launch.

... doesn't the depth of a submarine effect its top speed? Intuitively the pressure of the water around it should have some short of drag increase? Or am I mistaken? I know that torp speed is depth sensitive, why not subs?

.. how far can a ultra low frequent radio wave travel in water? What if we link a underwater radio antenae directly to reactor output and pump a 10-100 megawatts thru it? How far would the signal reach thru the water? Would it be detectable on the surface?

.. what's the deal with UUV "Gliders"? Its not like "lift" is a problem in water like it is in air. Why would a "glider" in water have increased range?

.. what do you think the performance characteristics of the new half-length torpedo are likely to be in terms of range and speed? I know it has "increased broadband resolution" meaning better littoral warfare application, but doesn't its smaller size retard the range of the torps significantly?

.. where's the high frequency sonar mounting on the Akula? It could be on the sail, but isn't its sail too far back to give a good forward view?

... what's the true length of a ship wake? DW has wake homers homing in from miles behind the ship? Is a ship wake really *that* long and/or wakehomer sensors *that* sensitive? How do wakehomers really detect a "wake" anyway? I've heard that its highfreqency sensor detecting the wake noise, but is that all?

Anyone got any favorite forums where things like this are discussed?

[RedDevilCG]

what's the deal with UUV "Gliders"? Its not like "lift" is a problem in water like it is in air. Why would a "glider" in water have increased range?

I am going to tackle this one first because I think it is pretty cool.

General categories of "flying"
-Alright, so you have powered flight (using engines, jets etc.) using thrust to move, and non-powered flight (gliders, jets with broke engines, squirrels etc.) using another force to move.
-You can also say you have heavier than air craft (planes, gliders), and lighter than air craft (baloons, zeplins etc.).
-You generally see wings on heavier than air craft, and wings work best once they are moving at speed, and do little when you are stopped.

Okay, so now to fly we need a way to get moving. A jet uses engines producing thrust to get the speed to have its wings work. A glider uses gravity (mostly) to get the speed to gets its wings going. Once the wing gets going, it uses the resistance (and 'suction') of air to direct it's path regardless of other forces, we call this "lift", though it doesn't really always have to do with gravity.

Okay, so how does this apply to underwater? Well water can be thought off as really-really thick air. So once again, you take a heavier than water craft, and put wings on it. Once again gravity is going to give the craft some force and speed, and the underwater wings, once they get going, are going to provide "lift". This allows an underwater glider to "glide" from a high point in the water, until it eventually lands on the sea floor. See how this can make something with wings travel farther?

Now another effect that is even cooler is this: Things can both, sink AND float in water. Fish do this with swim bladders, and submarines do this with balast tanks. By making themselves less dense than water (filling up with air) they float, and by making themselves more dense than water (usually pumping that air out, or letting water in) they sink! Make a UUV with balast tanks like a sub, and a battery allowing water in, and pushing the water back out again, and you have a vehicle that can sink, float, sink, float etc. Throw a wing on it, and it 'glides' along laterally to the bottom of the sea when sinking, then glides along laterally back up to the top when floating! This can go on forever or until the batter runs out, which ever is first.

Flying underwater with no engine producing thrust, and almost no moving parts: Efficient and quiet!

Super Cool huh? (yeah I am a geek).