SRB Fuel Types

[PositronLance001]

I think SRB's should be modifiable with different fuel types ie. less thrust, less consumption, lower ISP, high thrust, etc. They should be part upgrades, and have different costs as to not be OP.

[Mikenike]

A good idea, but does NASA have three different Solid fuel types. KSP is meant to be as realistic as possible, while being unique, and have a little extra fun while doing it. 

[Pds314]

On 11/13/2019 at 10:02 AM, PositronLance001 said:

I think SRB's should be modifiable with different fuel types ie. less thrust, less consumption, lower ISP, high thrust, etc. They should be part upgrades, and have different costs as to not be OP.

Why would SRBs have multiple fuel types when our equivalent to a V2 engine, an F-1, a fuel cell, and an SSME all use the same thing, which is also what turboramjets, high bypass turbofans, turbofans, and nuclear rockets use sans oxidizer? When in reality most of these use slightly to very different fuels/propellants.

 

I could see a "fuel grain size" slider for this though. That or diversifying LF and oxidizers as well.

Edited November 17, 2019 by Pds314

[linuxgurugamer]

For example, one fuel can burn fast and give a lot of thrust, another would be a slower burning type less thrust but for a longer time.

My mod ModularSegmentedSRBs will eventually have different grains, not sure about the fuel types yet.

 

[JadeOfMaar]

2 hours ago, Pds314 said:

Why would SRBs have multiple fuel types when our equivalent to a V2 engine, an F-1, a fuel cell, and an SSME all use the same thing, which is also what turboramjets, high bypass turbofans, turbofans, and nuclear rockets use sans oxidizer? When in reality most of these use slightly to very different fuels/propellants.

 

I could see a "fuel grain size" slider for this though. That or diversifying LF and oxidizers as well.

On 11/13/2019 at 2:02 PM, PositronLance001 said:

I think SRB's should be modifiable with different fuel types ie. less thrust, less consumption, lower ISP, high thrust, etc. They should be part upgrades, and have different costs as to not be OP.

I think there is only one standard chemical formula for SolidFuel: Aluminum + Ammonium Perchlorate. It gets the job done and it burns clean, I think. I'm not aware of any other solid fuel that contains its oxidizer in itself. Hybrid solids may exist (they do in concept anyway) that accept a SolidFuel and a liquid oxidizer but you never hear about them. Correct me if I'm wrong but IRL, their advantages aren't worth the added complexity of the engine/exit machinery. So in KSP, if you want "other fuels" just go LFO.

You can achieve a lot of the performance tuning dynamics of a solid rocket just by customizing its nozzle. The nozzle's throat width affects thrust, the throat to exit width ratio affect Isp, the bell length and bell curve (like on any liquid rocket) also affect Isp. @linuxgurugamer just has to envision that for his mod. The remainder and most important portion of the performance tuning lies in the grain geometry which affects thrust as the fuel runs out. There are 6 prominent geometries, and from the looks of their curves, 2 of these are great for Vac kick stages and would suck for sea-level lifters.

1 hour ago, linuxgurugamer said:

For example, one fuel can burn fast and give a lot of thrust, another would be a slower burning type less thrust but for a longer time.

I'd put away the idea of fuel options due to how dominant the perchlorate formula is. The stock feature Throttle Limit already delivers that bit and simulates having an appropriately smaller nozzle.

 

[linuxgurugamer]

6 minutes ago, JadeOfMaar said:

I'd put away the idea of fuel options due to how dominant the perchlorate formula is. The stock feature Throttle Limit already delivers that bit and simulates having an appropriately smaller nozzle.

The Throttle Limiter is disabled in my mod.  However, having 3-4 set settings which can be selected might not be a bad idea.

Edited November 17, 2019 by linuxgurugamer

[Pds314]

1 hour ago, JadeOfMaar said:

Hybrid solids may exist (they do in concept anyway) that accept a SolidFuel and a liquid oxidizer but you never hear about them. Correct me if I'm wrong but IRL, their advantages aren't worth the added complexity of the engine/exit machinery.

I think the Hwasong-14 used by North Korea may use a hybrid solid fuel upperstage developed by scientists in Ukraine and then modified for domestic production. But that's pretty much one step above speculation so take that (and almost all other information about North Korea, whether from the state itself, hearsay like this, rival states, the mainstream media, NGOs, allied states, or defectors) with a grain of salt about the size of Mt. Paektu, and the fact that we need to look at an ICBM (and not an orbital launch vehicle) used solely by not even a regional power is indicative of how rare these kind of motors are.

Edited November 17, 2019 by Pds314