Mutiple engine ISP

[DunaManiac]

Does anyone know what the ISP of mutiple engines with the same ISP is? IS it the same or to I divide by the number of engines? Thanks.

[Spricigo]

Since isp is just how much thrust/fuel comsumption the engines can produce it'll not change if you expend n times more fuel to produce n times more thust.

 

[Reactordrone]

The only time you have to work out the Isp for multiple engines is when you have engines with different performance combined. if they all have the same Isp then the group Isp is the same as that for an individual engine.

[wumpus]

15 hours ago, Reactordrone said:

The only time you have to work out the Isp for multiple engines is when you have engines with different performance combined. if they all have the same Isp then the group Isp is the same as that for an individual engine.

Of course, strapping on SRBs around a liquid core is common in KSP and real life.  At that point I let Kerbal Engineer (a mod) take care of it.

[Spricigo]

1 hour ago, wumpus said:

Of course, strapping on SRBs around a liquid core is common in KSP and real life.  At that point I let Kerbal Engineer (a mod) take care of it.

Also worth noticing: that's when Isp become less important.