Jump to content
  • 0

how to enable realtime adaptive delta v and twr?


Valiant
 Share

Question

Not sure if im even asking the right question. Lets say for instsance, I build a massive ship designed to travel the solar system. And on this ship I have multiple engine groups that i can toggle via the actions menu. Some are for efficency and others are for high thrust and others even are for finetuning maneuvers. The problem is, no matter which engine groups are active the delta v available and the current twr readout over in the staging section remains the same which makes performing maneuvers kind of a guessing game at burn times, whether i have enough fuel, and when to start each burn. Am i missing something?

Link to comment
Share on other sites

2 answers to this question

Recommended Posts

  • 0

I've not tried something like that myself, but perhaps you can work around this by spreading your engine groups across multiple stages.

Now, I don't mean stages you actually stage. Rather, when I think massive mothership, I think of a vessel that is already on its final stage. It can undock and re-dock vessels for refuelling operations, but none of that is done through actual staging. That means you're not pressing spacebar anymore. So... just create some virtual stages that don't do anything except having groups of engines in them.

Then, in flight, you can pop out the expanded stage info, and receive information for that specific stage, such as its remaining burn time and its acceleration. This display does update as you manually toggle engines via action groups, IIRC. Note that in order to customize what info the expanded stage view shows you, you have to go into the VAB and set it there. It's a global setting, not a vessel-specific one.

Link to comment
Share on other sites

  • 0

Dealt with this problem, but in general for large ships the deltaV readout cannot be trusted. Even if you managed to get the game to give you the real deltaV value for the current engine configuration you are using, unless you keep burning until the end in this configuration, it's not going to reflect your actual mission.

what I did was set up an excel datasheet to calculate the deltaV.

My mothership had a mixture of nervs and wolfhounds, like yours I guess. So my datasheet had 3 key inputs: dry mass, LF, Ox. Dry mass changed depending on how many life support resources I would carry, if you're not dealing with that you can keep that constant.

and I had some different outputs:

"first chemical, then nuclear": that is, if I burn my chemical rockets completely, and then finished with nuclear. This gives the lowest deltaV on chemical engines, but the highest with nuclear. The calculation is

=4379*LN((Dry+LF+Ox)/intermiediate mass), where I did calculate intermediate mass as "Dry+LF-(Ox*10,6/11,07).

A bit of clarifications here: 4379 is the average Isp*g that I calculated for the specific mixture of wolfhounds and nervs I was using (1:1 ratio), that I got by multiplying each engine thrust by its Isp and then making an average. The ratio 10,6/11,07 is the ratio of consumed liquid fuel to oxydizer; again it's something I calculated for my specific case, taking into account the wolfhounds using it in 9/11 ratio and the nervs using only liquid fuel.

Then deltaV nuclear is 8000*LN(intermediate mass/Dry)

I also have, made similarly, the "first nuclear, then chemical", where I would of course burn the nuclear fuel first, keeping just enough LF to completely drain the oxydizer, and this would give higher values in chemical deltaV and lower values of nuclear.

And finally, a third line with additional input "leave behind X tons of oxydizer", where I would burn all the oxidizer save for X, then burn nuclear, then finish with chemical. This is the more complicated figure, but it's the one relevant to take off from a planet, then perform a mission, then land somewhere else.

For example, I am refueling on Ike, I take off, perform a mission, plan to land on Mun. So first I fiddle around with the "leave behind X oxydizer", until I find that 130 tons of oxydizer will give me 450 m/s high thrust at the end. This is enough to land on Mun, with a low thrust burn at the beginning. I finished refueling on LF, that's 2285 tons, and I have 1900 tons of dry mass. I try different amounts of starting Ox: with 200 tons, if I save 130 for the end, I have 110 m/s high thrust, followed by 5500 m/s low thrust, followed by 450 m/s high thrust. but the starting high thrust value is too small to leave Ike, so I try to raise the Ox to 300 tons, and now I get 270 m/s high thrust, followed by 5350 m/s low thrust, and finally again 450 m/s high thrust.

This is the most accurate method I found of estimating my deltaV, and the game can't do it.

If you are interested, I can give more help to build a datasheet

Link to comment
Share on other sites

This thread is quite old. Please consider starting a new thread rather than reviving this one.

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Answer this question...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...