Jump to content

seanth

Members
 View Profile  See their activity

  • Posts

    891

  • Joined

  • Last visited

 Content Type 

Everything posted by seanth

  1. seanth
    Bravo! I hope to follow in your footsteps soon
  2. seanth
    Sober, calculated, and posted. That is a monster of a craft!
  3. seanth
    Finished testing Franklin My Dear for distance (I made it to a point just northwest of the island off by itself in the Western Ocean), and started testing s new ship. Hello eclipse. AND, cargo bay doors are weird in terms of drag.
  4. seanth
    I've been designing my stuff so they get up out of the water and at what I consider an ideal height when the overall lift in kN is less than the weight (in kN) of the craft. That way I am guaranteed that my ships won't become planes by mistake. My problems come when I crank up the speed and the lift increases. But that's why I stack my foils: as foils leave the water, the craft gets less lift.
  5. seanth
    In the craft I have been designing, I have stacked foils, and you can see changes in lift as my craft rise out of the water: the uppermost foil lift arrows shrink as the leave the water's surface. That makes perfect sense since I'd expect a foil to have more lift in water at low speed than in air at the same speed. What is not at all clear to me is how that applies to big foils that are sort of vertically in water and air. @foamyesque's hydrofoil2 has those angled back wings that provide net lift up and out, and the front ones provide net lift up and in. If KSP was doing the math correctly, as those angled wings rise up in the water--and thus have less wing in the water--they should provide less lift and a given speed. Right? I suspect that KSP is seeing them touching the water and giving them water-lift values for the entire wing surface.
  6. seanth
    I'm inclined to agree. Maybe it's time to wrap up this challenge unless someone can think of a way to salvage it with rule tweaks or a reformulation of the scoring.
  7. seanth
    That is a big ship. Take another screenshot showing the mass, # of parts, and the thrust and I'll list you.
  8. seanth
    It's just a thing of beauty. Scores are posted. You're officially in 1st in all categories, though different boats.
  9. seanth
    WOW! That is amazing! I love it. Craft file available?
  10. seanth
    Huh. So...does that mean that a craft with two Goliath engines operating at 50% would have a better overall thrust than the same craft with a single engine working at 100%? Edit: no. derp. The performance is related to speed. Unfortunately, I think the way the rules ended up the being formulated, there's only one way to beat a Power score, and that's by increasing speed. Thrust and fuel consumption are pretty tightly linked, so as you increase your thrust you are increasing your fuel usage. There's just no way to decouple thrust and fuel usage that I can think of. I wonder what scores would look like if we had gone with the original (mass*velocity)/Ls-1/#parts formulation. To the spreadsheets! Person Ship name Momentum/L/s/part (foamyesque) We don't need no stinkin' hydrofoils 214.43 (foamyesque) Unnamed 146.92 (Ezriilc) Orca 5.3 143.64 (The_Rocketeer) Soviet R 124.95 (seanth) Franklin My Dear, I Don't Give A Damn 120.68 (seanth) Crick in my Neck 113.54 (Ezriilc) Orca 6 101.47 (seanth) Crick in My Neck-full throttle 97.85 (Ezriilc) Orca 3.4 64.20 (Ezriilc) Sea Train 89.85 (Ezriilc) Sea Train-depleted fuel 63.17 (SpannerMonkey(smce)) Challenge Cat 55.09 (seanth) Watson Your Mind 22.22 I find the values for Crick in My Neck and The Sea Train of particular interest here, because those craft have two entries under two different operating conditions. Crick in My Neck scored better at lower speeds, even though the mass was essentially the same; probably due to better fuel efficiency at lower speeds. The Sea Train also scored better at lower speeds, but because the faster run had much less mass. If we were to think about scoring this way, what sort of crafts would be able to tie with @foamyesque's We don't need no stinkin' hydrofoils? To make it easy, let's lock in velocity at 90m/s and the fuel usage at that speed to 1.75L/s You could equal that score with a ship that was 334 tonnes and 80 parts (the current average number of parts per ship), traveling at 90m/s and using 1.75L/s of fuel to do so. Blarg. Maths.
  11. seanth
    DOH. I am an idiot. You are absolutely correct. I'm fixing your score on the 1st post now.... And I have to say, I am a bit confused that you got such great thrust. 16 Goliath, with an ideal thrust of 360kN is 5760kN. You're wallowing in that ship, but your thrust is 4756kN. That's 82% of optimal thrust. Doesn't seem like it should be that high, but you've clearly hit upon a design that is working!
  12. seanth
    Actually, maybe you do need hydrofoils.... I get a different value for your Power-fuel efficiency value Thrust: 179kN Velocity: 90.6m/s Fuel usage: 7.70L/s (179*90.6)/7.70 = 2106.16 Rest of the numbers look good. Hey! This means with your two entries, you are in 1st place in two categories (and last place in one )
  13. seanth
    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
  14. seanth
    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. Sure. I'll accept it for this one time
  15. 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.
  16. 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. 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.
  17. seanth
    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....
  18. 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.
  19. seanth
    Math wrong, or am I impressing you?
  20. seanth
    Not an official entry: Momentum/Fuel: 10185.25 Closer....
  21. seanth
    Oh, you misunderstood. 32.4m/s using 1.04L/s
  22. 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
  23. seanth
    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.
  24. seanth
    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.
  25. seanth
    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.
×
×
  • Create New...