Boat Momentum Efficiency Challenge

[The_Rocketeer]

Lol u guys, I give u a tip (less mass = more efficient) and u guys go nuts exploiting it!

The Rocketeer will return, but he's been Elcanoing. Give me a few days

[seanth]

3 hours ago, The_Rocketeer said:

Lol u guys, I give u a tip (less mass = more efficient) and u guys go nuts exploiting it!

The Rocketeer will return, but he's been Elcanoing. Give me a few days

One of the things I'm liking about this challenge is that there are a few ways to achieve a similar score.

You can definitely drop the mass of your ship to try and get a high score, but you end up losing out on the momentum (mass*speed) part of the equation. I'll give an example:

When I started work on Crick in My Neck(CIMN), it weighed much more than my first entry Watson on your Mind(WOYM), but it's power score was lower than WOYM's. Over the design iterations I was able to get the score to go from ~20k to ~40k. Squeezing an additional 20k out was more difficult.

This probably is too much inside-baseball talk, and just goes to show what a nerd I am but I recorded various performance variables, paying close attention to thrust and drag when CIMN would reach 32.4m/s (the speed that early designs had the boat body up out of the water.

 

Sometimes a design direction wouldn't be working out and I would have to revert to earlier designs. You can see how drag would go back up around iteration 15 and 25, and then suddenly drop again. That's because I would abandon a design idea and go back to what had been working better.

In the end I had a ship I was pretty pleased with. Maybe it could have taken the lead in the Power score, but I didn't want to sacrifice the mass, and it seemed like it was time to work on the next design.

So what I'm trying to say is there's more than one way to get really good scores here, and that's super cool! My approach is pretty tedious, and I'm loving seeing what other people are doing.

[Ezriilc]

13 minutes ago, seanth said:

One of the things I'm liking about this challenge is that there are a few ways to achieve a similar score.

You can definitely drop the mass of your ship to try and get a high score, but you end up losing out on the momentum (mass*speed) part of the equation. I'll give an example:

When I started work on Crick in My Neck(CIMN), it weighed much more than my first entry Watson on your Mind(WOYM), but it's power score was lower than WOYM's. Over the design iterations I was able to get the score to go from ~20k to ~40k. Squeezing an additional 20k out was more difficult.

This probably is too much inside-baseball talk, and just goes to show what a nerd I am but I recorded various performance variables, paying close attention to thrust and drag when CIMN would reach 32.4m/s (the speed that early designs had the boat body up out of the water.

snipped image

Sometimes a design direction wouldn't be working out and I would have to revert to earlier designs. You can see how drag would go back up around iteration 15 and 25, and then suddenly drop again. That's because I would abandon a design idea and go back to what had been working better.

In the end I had a ship I was pretty pleased with. Maybe it could have taken the lead in the Power score, but I didn't want to sacrifice the mass, and it seemed like it was time to work on the next design.

So what I'm trying to say is there's more than one way to get really good scores here, and that's super cool! My approach is pretty tedious, and I'm loving seeing what other people are doing.

I believe it is the mark of a good engineer to better the design at each iteration, or go back.  That's how you win challenges.

[seanth]

4 minutes ago, Ezriilc said:

I believe it is the mark of a good engineer to better the design at each iteration, or go back.  That's how you win challenges.

Sure, but I fear getting trapped in a localized design optima. Sometimes you need to be willing to explore what seem to be terrible design ideas that lead to better overall results. I'm looking at you, thumbs.

[Ezriilc]

Just now, seanth said:

Sure, but I fear getting trapped in a localized design optima. Sometimes you need to be willing to explore what seem to be terrible design ideas that lead to better overall results. I'm looking at you, thumbs.

I know what you mean, that's why I love these challenges - they expand our horizons, as it were.

[The_Rocketeer]

53 minutes ago, Ezriilc said:

I know what you mean, that's why I love these challenges - they expand our horizons, as it were.

Coming to you from a current Elcano challenge attempt having crossed the equator 3 times already and currently within 20 degrees of latitude of the north pole, yes they do.

[Ezriilc]

On 7/12/2016 at 11:03 PM, The_Rocketeer said:

My first-pitch entry, the Soviet R:

If I've done the maths right, I think my scores are...

Parts efficiency score: 149.9 = (118.722 t * 78.3 m/s) / 62 parts
Fuel efficiency score: 46966.95 = (719.8 kN * 78.3 m/s) / 1.20 L/s
Momentum score: 7746.6 = (118.722 t * 78.3 m/s) / 1.20 L/s

I will try to refine and go again - watch this space

 

Still waiting on the .craft file for this.  I'd like to inspect your ship.

[The_Rocketeer]

Just now, Ezriilc said:

Still waiting on the .craft file for this.  I'd like to inspect your ship.

My bad, I'll get onto it.

Here.

It does have some real issues, so not my best work. I've already begun refining tho - my current Elcano craft is a beefed up version carrying 40440L of LF, cruising at 50m/s full and 90m/s with the tanks about a quarter full. Just had a minor catastrophe tho - got out of the water for my one short land-crossing and one of the planes has broken

Edited July 16, 2016 by The_Rocketeer

[seanth]

1 hour ago, The_Rocketeer said:

Coming to you from a current Elcano challenge attempt having crossed the equator 3 times already and currently within 20 degrees of latitude of the north pole, yes they do.

I have been eyeballing the Elcano challenge in relation to my interest in naval circumnavigation without refueling or using ISRU. 

[The_Rocketeer]

1 hour ago, seanth said:

I have been eyeballing the Elcano challenge in relation to my interest in naval circumnavigation without refueling or using ISRU. 

Yes, that's a future pursuit of mine also. I was working towards it with the Soviet series when this came up, but since launched a less ambitious refuellable mission. What I've learned so far is a craft capable of going non-stop must be both extremely large and really very efficient indeed.

[seanth]

21 hours ago, The_Rocketeer said:

Yes, that's a future pursuit of mine also. I was working towards it with the Soviet series when this came up, but since launched a less ambitious refuellable mission. What I've learned so far is a craft capable of going non-stop must be both extremely large and really very efficient indeed.

Nod. I feel like this challenge is a good prototyping and testing platform for the Elcano challenge (and a "Exploration Cruise" no-refueling challenge Ezriilc and I have been talking about.

[Ezriilc]

23 hours ago, The_Rocketeer said:

My bad, I'll get onto it.

Here.

It does have some real issues, so not my best work. I've already begun refining tho - my current Elcano craft is a beefed up version carrying 40440L of LF, cruising at 50m/s full and 90m/s with the tanks about a quarter full. Just had a minor catastrophe tho - got out of the water for my one short land-crossing and one of the planes has broken

Thanks!  I've had a very hard time trying to make something that can beat your Momentum Efficiency score, but now that I have your secret technology, I can finally rule the world! 

[Ezriilc]

For the record, I don't much like this ship because I feel it is abusing the fact that these jets don't mind being right on top of each other, and also that I could just keep adding more tanks and more engines and get better scores.  But, here it is.

I suspect that a different design may be able to do a bit better than this, such as what @The Rocketeer is using, but I'm not sure how far this can go beyond what we've already done.

Orca 5.3:
427.272 t
5456 kN
160.3 m/s
8.83 L/s
54 parts
Part:  1,268.364844444444
Fuel:  9,9048.33522083805 (corrected)
Momentum:  7,756.704597961495

Download here:  http://www.Kerbaltek.com/users/Ezriilc/Orca 5_3.craft

Edited July 17, 2016 by Ezriilc

[Ezriilc]

I am unable to duplicate the numbers for the Soviet R.

Its maximum mass before any fuel is burnt is 118.395 t.
Its best speed starting from a dead stop with tanks full is ~60 m/s (mass: 117.916 t).
Its maximum thrust at that point is 631.8 kN.

Can anyone do any better with this craft?  Am I missing something?

EDIT:  I was missing something - an engine on the back appears to have been ripped off when HyperEdit dropped her in the water.  MY BAD! 

EDIT:  I'm sorry, @The Rocketeer, your numbers look completely legit, and I have no reason to doubt them.

Also, that ship gets around on land pretty well, now that I've tried it.

Edited July 17, 2016 by Ezriilc

[seanth]

 

1 hour ago, Ezriilc said:

Orca 5.3:
427.272 t
5456 kN
160.3 m/s
8.83 L/s
54 parts
Part:  1,268.364844444444
Fuel:  264,008.6106455266
Momentum:  7,756.704597961495

I think you have a calculation error in there. The part score and the momentum socre look fine, but the Fuel (i.e "Power" score) should be:

(kN*m s^-1)/units of fuel per second = Fuel Efficiency Score

(5456*160.3)/8.83=99,048.34

Which is respectable, but isn't 264,000. I readily admit I was gobsmacked when I saw that number.

So you still have the trifecta right now, but I am not willing to give up on the contest when the power score is 99k. I am pretty sure I can match that.

 

 

[Ezriilc]

Just now, seanth said:

I think you have a calculation error in there. The part score and the momentum socre look fine, but the Fuel (i.e "Power" score) should be:

(kN*m s^-1)/units of fuel per second = Fuel Efficiency Score

(5456*160.3)/8.83=99,048.34

Which is respectable, but isn't 264,000. I readily admit I was gobsmacked when I saw that number.

So you still have the trifecta right now, but I am not willing to give up on the contest when the power score is 99k. I am pretty sure I can match that.

Good catch, thanks.

[Bubbadevlin]

Well, i have been gone for a while, and i mainly missed this, but does my stock paddleboat count? (its 1.0 and kinda cheaty) It technically uses no fuel, and can go on infinitely, so would that be a score of infinite? 

 

 

And here is the post from the Spacecraft Exchange  

Quote

 

 

[seanth]

2 hours ago, Bubbadevlin said:

Well, i have been gone for a while, and i mainly missed this, but does my stock paddleboat count? (its 1.0 and kinda cheaty) It technically uses no fuel, and can go on infinitely, so would that be a score of infinite? 

Huh. Interesting. Can you explain the scanner drive?(nm. I was able to figure it out) Put some screenshots up with part numbers, thrust, mass, all the other requirements, and we can try and figure out whether it qualifies.

EDIT: OK. I've been thinking about this a bit and think I know how to score this craft. Does it make sense to just ignore the fuel usage part of the equation in this case? The paddlewheel provides thrust (it has to, otherwise it won't move the vessel). MechJeb _might_ report the thrust value, but I'm not sure. I think MechJeb would report the acceleration of the craft, though. So to score this we'd need to see:

• Thrust. If thrust is not available, then acceleration.
• Mass
• Speed
• Part #

Let's assume the speed is 3m/s, 500 parts, mass of 50 tonne (I'm just guessing), and an acceleration of 0.5m/s²

We get the thrust by multiplying the mass by the acceleration (50 tonne*0.5m/s²=25kN)

And let's just drop the fuel usage part of the equation for an entry like this.

Using these guestimates and made up numbers, the scores would be:

• Part: Mass*speed/#parts=(50*3)/500= 0.3
• Power: (Thrust*speed)=(mass*acceleration*speed)=(50*0.5*3)=75
• Momentum: (Mass*speed)=50*3=150

If I get ambitious, I might load up the ship and get the actual numbers just to score it officially.

Edited July 19, 2016 by seanth

[Bubbadevlin]

7 hours ago, seanth said:

 

If I get ambitious, I might load up the ship and get the actual numbers just to score it officially.

Haha thanks, it was mainly just a joke, as that boat no longer functions in 1.1, but i think you guessed about right. I may still however try to make a legit entry, it i have the time 

[Ezriilc]

@Bubbadevlin, she certainly is a beautiful craft.  Well done - regardless of whether she competes here.

[Ezriilc]

Re: KSS Klermont, I cannot get any movement, and the scanner is already rotating, just nothing else.  It was mentioned that it doesn't work in 1.1, so I guess that's still true.

I'm sad 'cuz I wanted to see her go.

[seanth]

I love my latest design. 170ton, up in hydrofoils below 30m/s, uses only 1.04L/s fuel while cruising at 32.4m/s.

BUT, I keep losing control above 110m/s.

@Eriilc: I'm coming for you

[Ezriilc]

2 minutes ago, seanth said:

I love my latest design. 170ton, up in hydrofoils below 30m/s, uses only 1.04L/s fuel while cruising at 32.4m/s.

BUT, I keep losing control above 110m/s.

@Eriilc: I'm coming for you

Bring it!

I can't wait to see it.  170 tonnes at 110 m/s with only 1.04 L/s ??!!  I'll believe it when I drive it.

[seanth]

5 minutes ago, Ezriilc said:

Bring it!

I can't wait to see it.  170 tonnes at 110 m/s with only 1.04 L/s ??!!  I'll believe it when I drive it.

Oh, you misunderstood. 32.4m/s using 1.04L/s

Edited July 19, 2016 by seanth

[Ezriilc]

1 minute ago, seanth said:

Oh, you misunderstood. 32.4m/s using 1.04L/s

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