Boat Momentum Efficiency Challenge

[seanth]

1 hour ago, Ezriilc said:

But that's only a 5,296 Momentum/Fuel funzies score.  I thought you were coming for me. 

Not an official entry:

Momentum/Fuel: 10185.25

Closer....

[Ezriilc]

2 minutes ago, seanth said:

Momentum/Fuel: 10185.25

The hell you say! 

[seanth]

4 minutes ago, Ezriilc said:

The hell you say! 

Math wrong, or am I impressing you?

[Ezriilc]

Just now, seanth said:

Math wrong, or am I impressing you?

[double-checks the math]  You're impressing me.  How the hell?  I can't seem to get over 7k to save my life.

Now I gotta load up your ship and steal all your tech.

[seanth]

The problem I'm running into is I optimize the hell out of it at low speed, and when I crank it up to full speed it goes boom.

It's like taking an elephant and then giving it the speed of a cheetah. While I have not seen an elephant run as fast as a cheetah, I can't imagine it ending well.

 

Re stealing tech: I'll definitely put the craft up for you to grab. If the final isn't as good at momentum, I'll point out what revision that above picture is from.

Edited July 19, 2016 by seanth

[Ezriilc]

15 minutes ago, seanth said:

Re stealing tech: I'll definitely put the craft up for you to grab. If the final isn't as good at momentum, I'll point out what revision that above picture is from.

No matter.  I believe I have what I need.

[Ezriilc]

I realize this is supposed to be a competition, but I can't help but share my eureka moment with those who can appreciate it - while the adrenaline is fresh.

Upon noticing the type of part you're ultimately using as your ski (the tailfin), I decided to try something that I had been thinking of with regard to porpoising.

I learned earlier in this challenge that if I create a V shaped (side-to-side) fin set, it completely eliminated chine-walking (no chines to walk).  I tried to think of a way to implement that thinking against porpoising, but it was difficult because obviously a V shape (fore-to-aft) wouldn't do.  The key is one long ski, or at least one continuous lift area the length of the hull.

The result is nothing less than breathtaking.  My speed of about 125-140 (unsafely due to porpoising) shot up to well in reach of 250 m/s - with zero porpoising!

I wanted to let you post your entry beating mine before I make an official run, but couldn't keep this to myself so there ya go. 

[seanth]

6 minutes ago, Ezriilc said:

I realize this is supposed to be a competition, but I can't help but share my eureka moment with those who can appreciate it - while the adrenaline is fresh.

Upon noticing the type of part you're ultimately using as your ski (the tailfin), I decided to try something that I had been thinking of with regard to porpoising.

I learned earlier in this challenge that if I create a V shaped (side-to-side) fin set, it completely eliminated chine-walking (no chines to walk).  I tried to think of a way to implement that thinking against porpoising, but it was difficult because obviously a V shape (fore-to-aft) wouldn't do.  The key is one long ski, or at least one continuous lift area the length of the hull.

The result is nothing less than breathtaking.  My speed of about 125-140 (unsafely due to porpoising) shot up to well in reach of 250 m/s - with zero porpoising!

I wanted to let you post your entry beating mine before I make an official run, but couldn't keep this to myself so there ya go. 

HI5! Excellent realization.

It's funny you mention that. In frustration, I started playing with one big wing on the sides in a catamaran design, sort of like The_Rocketeer's Soviet designs. Your experiments confirm that it would solve the porpoising, but it had massive drag so I bailed on that design.

I'm still thinking about that design, though....

[Ezriilc]

4 minutes ago, seanth said:

HI5! Excellent realization.

It's funny you mention that. In frustration, I started playing with one big wing on the sides in a catamaran design, sort of like The_Rocketeer's Soviet designs. Your experiments confirm that it would solve the porpoising, but it had massive drag so I bailed on that design.

I'm still thinking about that design, though....

I'm finding the same to be true, that is why seeing your design sparked my desire to try it, thinking correctly that it was less draggy.

[seanth]

Gug. I think this design is best for slow, long distance stuff. I managed to get this design to 120m/s, but only but very carefully adjusting the angles of the hydrofoils, and it was only for an instant. 

To have any shot of taking the lead for the power score, I need to get this going at least 160m/s, while maintaining my hard earned fuel efficiency. 

On the way home I had an idea I can try. It'd make the ship a terrible pig at low speeds, but should regain the fuel efficiency once it reaches full speed if I do it right. Stay tuned I guess.

 

5 hours ago, Ezriilc said:

I learned earlier in this challenge that if I create a V shaped (side-to-side) fin set, it completely eliminated chine-walking (no chines to walk).  I tried to think of a way to implement that thinking against porpoising, but it was difficult because obviously a V shape (fore-to-aft) wouldn't do.  The key is one long ski, or at least one continuous lift area the length of the hull.

It'd be cool to make a summary list of the things we are learning. Things like your V to solve chine walk. There's also the basics, like airplane jets on a boat force the nose down (in real life and KSP), and one way to deal with porpoising on hydrofoils is to move the center of lift close to the COM or even just behind it. It's tricky balancing the jets forcing the nose down, where bouyancy is, and where lift will be as the boat's angle in the water might change as hydrofoils lift it up.

Edited July 20, 2016 by seanth

[foamyesque]

I'm personally more interested in the momentum/fuel score, myself, so I went big.

 

 

I believe that's 30,365, no?

 

EDIT:

I forgot to put a Kerbal on, but come on, d'ye really think that's gonna impact this thing?

 

Edited July 20, 2016 by foamyesque

[The_Rocketeer]

3 hours ago, foamyesque said:

I'm personally more interested in the momentum/fuel score, myself, so I went big.

 

 

I believe that's 30,365, no?

 

EDIT:

I forgot to put a Kerbal on, but come on, d'ye really think that's gonna impact this thing?

 

Aaaaaand... we're back to the behemoth race.

[Ezriilc]

2 hours ago, The_Rocketeer said:

Aaaaaand... we're back to the behemoth race.

Yep, and that's a pretty easy road too.  The lifting body parts work quite well at slow speeds with no fins at all, so the bigger you go, the bigger the score.

[seanth]

Gurrrrr! I just can't solve the porpoising with this craft design. I'm going to use that previous screen shot as an official entry and put in the relevant data. @Ezriilc: let's see the results of your breakthrough.

Ship name: Franklin My Dear, I Don't Give A Damn

• Mass: 167.609
• Thrust: 1234 
• Velocity: 115.2
• L/s: 2.00
• Parts: 80

 

• Power score: 71,078.40
• Part score: 241.36
• Funzie momentum/L/s score: 9,654.28

Craft files: https://github.com/kjoenth/KSP-Boat-Momentum-Challenge/tree/master/seanth entries

Now I'm going to revert to an earlier design (version42 or 43) and see how far it will let me go. With only 345kN of drag at 32m/s, using 1.05L/s of fuel, I feel like this could go a LONG way.

Edited July 20, 2016 by seanth

[Ezriilc]

1 minute ago, seanth said:

Gurrrrr! I just can't solve the porpoising with this craft design. I'm going to use that previous screen shot as an official entry and put in the relevant data. @Ezriilc: let's see the results of your breakthrough.

Fair enough, if you post the .craft file.

It turns out that this craft is a true freak - although it will do this every time, any changes, and I mean anything at all, and it just doesn't survive getting up on the small planes.  I got very lucky with this particular build, but I can't seem to get any more out of it.  It's a good thing I thought to save the version permanently.

I will attempt to beat @foamyesque's entry (a tip of my hat to you), but I suspect we are fighting a never ending battle, as @The Rocketeer suggests.

Orca 6:
420.056 t
4763 kN
247.7 m/s  <<< Wow!
7.71 L/s
133 parts
Part:  782.3148210526316
Fuel:  153,021.4137483787
Momentum/Fuel:  13,495.18433203632

Download: http://www.kerbaltek.com/users/Ezriilc/Orca 6.craft

[foamyesque]

5 hours ago, Ezriilc said:

Yep, and that's a pretty easy road too.  The lifting body parts work quite well at slow speeds with no fins at all, so the bigger you go, the bigger the score.

 

I have no lifting parts in the water. Too much drag; I built a boat. The road to improving it is to go bigger and slower, but I already had a great deal of trouble putting that in the water in the first place -- I had something like [/s]40[/s] 26 crawler wheels to horse it around and I burned through 80,000 electrical units just to veer it off the runway and straighten it out again. :v

Edited July 20, 2016 by foamyesque

[Ezriilc]

1 minute ago, foamyesque said:

I have no lifting parts in the water. Too much drag; I built a boat. The road to improving it is to go bigger and slower, but I already had a great deal of trouble putting that in the water in the first place -- I had something like 40 crawler wheels to horse it around and I burned through 80,000 electrical units just to veer it off the runway and straighten it out again. :v

I tried this way, but I didn't get the dramatic speeds that turn me on so much, so I abandoned it.  Still, there may be something to it, so I'm gonna do my best.

BTW, to move your craft, just use HyperEdit's Ship Lander - pre-approved for this challenge.

[foamyesque]

My version of hyperedit's outta date, the ship lander doesn't do anything ATM and I haven't gotten 'round to updating it. 'sides, I like to do things legit, and this looks kinda impressive in its own right...

 

 

:v

[Ezriilc]

1 minute ago, foamyesque said:

My version of hyperedit's outta date, the ship lander doesn't do anything ATM and I haven't gotten 'round to updating it. 'sides, I like to do things legit, and this looks kinda impressive in its own right...

"Impressive" is one way to put it, yes. 

[seanth]

7 minutes ago, foamyesque said:

 

I have no lifting parts in the water. Too much drag; I built a boat. The road to improving it is to go bigger and slower, but I already had a great deal of trouble putting that in the water in the first place -- I had something like 40 crawler wheels to horse it around and I burned through 80,000 electrical units just to veer it off the runway and straighten it out again. :v

You're 100% correct: bigger and slower. Pretty much the limiting factor on ship size has been the size of the Panama Canal. Now that it's bigger, ships will grow, too.

Boats are _super_ efficient at moving large masses around very slowly. In fact, I wrote a paper on it. 

http://bioscience.oxfordjournals.org/content/early/2015/06/26/biosci.biv081

A few years ago @Ezrillic and I did a straight-up momentum boat challenge. That's why the momentum/L/s score is just for funzies. Having said that, I'm considering putting an "average" score on the first post like @The_Rocketeer suggested. 

11 hours ago, foamyesque said:

I forgot to put a Kerbal on, but come on, d'ye really think that's gonna impact this thing?

 

Sure. I'll accept it for this one time

[foamyesque]

Speaking of scoring, the "power efficiency" thing is effectively equivalent to Isp * speed, which suggests to me the optimal course for it is basically the Sea Train approach @Ezriilctook; something long and thin and large, all of which serve to reduce drag losses in proportion, powered by goliaths for maximum Isp.

[seanth]

20 minutes ago, foamyesque said:

Speaking of scoring, the "power efficiency" thing is effectively equivalent to Isp * speed, which suggests to me the optimal course for it is basically the Sea Train approach @Ezriilctook; something long and thin and large, all of which serve to reduce drag losses in proportion, powered by goliaths for maximum Isp.

I was pretty sure I could catch @Ezriilc using my general design when his velocity was ~160m/s, but with his latest design going almost 250m/s (are you sure it is still in the water?), I'm not convinced the "water strider" design will work out. I just can't see the legs being able to cope. I need to think on it a bit.

I looked at averaging the scores, but rankings don't change at all with the exception of @foamyesque's entry.  That unmanned ship ends up in an averaged ranking of 10th place, after Soviet R and before Challenge Cat

[Ezriilc]

Just now, seanth said:

are you sure it is still in the water?

  Yep!  Give her a try, you'll like it.  You don't even need SAS - in fact it may mess things up.  But I don't recommend trying to maneuver at those speeds.  And mark my words about her being a freak.  I tried to take off the lights and she nosed in at ~200.

[HafCoJoe]

On ‎7‎/‎19‎/‎2016 at 3:11 PM, Ezriilc said:

I realize this is supposed to be a competition, but I can't help but share my eureka moment with those who can appreciate it - while the adrenaline is fresh.

Upon noticing the type of part you're ultimately using as your ski (the tailfin), I decided to try something that I had been thinking of with regard to porpoising.

I learned earlier in this challenge that if I create a V shaped (side-to-side) fin set, it completely eliminated chine-walking (no chines to walk).  I tried to think of a way to implement that thinking against porpoising, but it was difficult because obviously a V shape (fore-to-aft) wouldn't do.  The key is one long ski, or at least one continuous lift area the length of the hull.

The result is nothing less than breathtaking.  My speed of about 125-140 (unsafely due to porpoising) shot up to well in reach of 250 m/s - with zero porpoising!

I wanted to let you post your entry beating mine before I make an official run, but couldn't keep this to myself so there ya go. 

Dude... I'm not entering the competition but is there any chance you could send me your craft file? I would love to see what you did so I can use it in a hydrofoil boat I'm hoping to use on Laythe in an upcoming project. I've never heard of something so preposterously fast before.

[Ezriilc]

1 minute ago, Avera9eJoe said:

Dude... I'm not entering the competition but is there any chance you could send me your craft file? I would love to see what you did so I can use it in a hydrofoil boat I'm hoping to use on Laythe in an upcoming project. I've never heard of something so preposterously fast before.

Sure!  I love sharing.  Here: