Comments (2)
First of all, my sincere apologies for a very late reply. I am currently very busy with other projects and, sadly, I admit I have neglected PEGAS. I will try to be more attentive of it in the future.
Regarding the actual issue. Although I haven't tried myself, it should already be possible to implement asparagus staging in PEGAS - the only nuance is that you have to do (some of) the math yourself. Let's assume there is one core booster and n
secondary boosters that will be jettisoned in pairs. For simplicity we will assume that those boosters are exactly same as the core booster - both in mass and engines (it's still doable if they differ, although with more math to work through). Since it's asparagus, all of the boosters are fed from the last two ("last" meaning: those that will be jettisoned next) -- the strong assumption is that whenever you stage, you drop two empty tanks, and all of the remaining tanks are fully fueled (as if the rocket was brand-new).
Some symbols now:
Mt
-- total mass of the vehicleMb
-- total wet mass of each boosterMf
-- mass of the fuel in each boosterFb
-- thrust of a single booster
If we denote Mr
as mass of the second stage (that is, rocket after the asparagus phase), then we can say that Mt = Mr + (n + 1) * Mb
.
Defining the first stage is the crucial point in understanding this. Its total mass and engine setup will remain the same (as if you weren't doing asparagus) - the only difference will be in massFuel
, since PEGAS calculates the staging time basing on this information. You want to drop the secondary boosters when they run out, so your massFuel
is equal to 2 * Mf
(this is saying: hit stage
when all of the engines burn through the fuel contained in the last two boosters). Your engines
have thrust
of (n + 1) * Fb
.
The next stage will now be a fully-fueled rocket, just without two of the boosters - . massTotal
is the old Mt
minus 2 * Mb
and massFuel
again is 2 * Mf
- after all, you want to stage after depleting the two boosters which are now the last ones. Of course, you have to modify the total engine thrust by subtracting the contribution of the two dropped ones: thrust
will be equal to (n - 1) * Fb
(initial count minus 2).
For the final stage this is all slightly different. Since now you only have the core booster supporting the rest of the stack, your massTotal
becomes Mr + Mb
and massFuel
is just Mf
(only a single booster of fuel to burn). The thrust
of your engines
is also only Fb
because you have the single core burning the fuel.
I hope this clears things up. For the less symmetric setup (i.e. your core booster has more/less engines than each of the jettisonable ones) you will probably have to use the full power of the engines
system and define each booster as a separate engine, letting PEGAS do the thrust/mdot summation math. Possibly also the masses calculation will be a little different, but with this explanation I think you should be able to do this on your own.
In case of any further questions, please reply in this thread and I'll try to give you any help I can.
from pegas.
Thanks, I have found a really crude way of solving my problem by tricking the computer into thinking that the amount of fuel in the center stage is the amount gained from the outer boosters + the total fuel used in the center stage and it works fine. I will try and make a more refined version using actual algebra.
from pegas.
Related Issues (20)
- Use PEGAS in landing HOT 3
- Setting postlaunch task HOT 3
- PEGAS porting HOT 1
- TestFlight/TestLite support HOT 4
- Add-ons? HOT 2
- Use PEGAS in orbital maneuvers HOT 1
- In game UI still says v1.1 HOT 2
- UI: Event timeline HOT 3
- Custom steering vector transform HOT 14
- Proposal: total overhaul of the event system
- How do I call a delegate? HOT 5
- Support for hotstaging HOT 4
- Certain configurations of the flight plan cause a crash HOT 5
- Atmospheric guidance switches from pitch-program to min-AoA during UPFG preconvergence
- gLim disengages HOT 10
- Custom engine spool-up config HOT 1
- PEGAS uses variables that conflict with built-in functions, breaking the script on newer versions of kOS HOT 4
- Failure to MECO on time in certain circumstances
- gLim causes an engine shutdown when reaching 0
Recommend Projects
-
React
A declarative, efficient, and flexible JavaScript library for building user interfaces.
-
Vue.js
🖖 Vue.js is a progressive, incrementally-adoptable JavaScript framework for building UI on the web.
-
Typescript
TypeScript is a superset of JavaScript that compiles to clean JavaScript output.
-
TensorFlow
An Open Source Machine Learning Framework for Everyone
-
Django
The Web framework for perfectionists with deadlines.
-
Laravel
A PHP framework for web artisans
-
D3
Bring data to life with SVG, Canvas and HTML. 📊📈🎉
-
Recommend Topics
-
javascript
JavaScript (JS) is a lightweight interpreted programming language with first-class functions.
-
web
Some thing interesting about web. New door for the world.
-
server
A server is a program made to process requests and deliver data to clients.
-
Machine learning
Machine learning is a way of modeling and interpreting data that allows a piece of software to respond intelligently.
-
Visualization
Some thing interesting about visualization, use data art
-
Game
Some thing interesting about game, make everyone happy.
Recommend Org
-
Facebook
We are working to build community through open source technology. NB: members must have two-factor auth.
-
Microsoft
Open source projects and samples from Microsoft.
-
Google
Google ❤️ Open Source for everyone.
-
Alibaba
Alibaba Open Source for everyone
-
D3
Data-Driven Documents codes.
-
Tencent
China tencent open source team.
from pegas.