I was playing around with the engine properties and found a funny thing.
the higher the throat and nozzle size is, the more thrust an engine makes.

I made 4 engines that are the same size, but have different nozzle sizes.
here are the engine nozzle and throat sizes:

-the engine on the left has a nozzle size of 1100%, and a throat size of 500%
(hidden properties were used, but only the nozzle and throat were changed.)

-the engine on the middle left has a nozzle size of 170%, and a throat size of 100%.

-the engine on the middle right has a nozzle size of 114%, and a throat size of 75%.

-the engine on the right has a nozzle size of 56%, and a throat size of 50%.

All the engines are optimized for sea level, they all also use Methalox as fuel and have an ISP of 337s.

heres the thrust of the engines:
-[Left: 5,524kN]
-[Mid left: 4,332kN]
-[Mid right: 3,897kN]
-[Right: 3,261kN]

Its funny tring to imagine that tiny thrust chamber on the left somehow making more thrust than all the other engines.

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    @Toinkove this normally wouldnt make sense, but it turns out the game increases fuel flow when the throat becomes wider, so the wide throat engine has a ridiculous amount of fuel flowing through it to compensate for the wider throat, it does make sense knowing that.

    7 months ago
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    353 Toinkove

    I guess the way I’m looking at it is: with the throat size that large, are you approaching the point at which there is essentially no “throat” and no division between combustion chamber and the nozzle itself (they essentially become the same chamber!
    ……..
    Of course you may have reached the nonsensical point by making the throat size 500% (like opening a door 500° expecting it will more open then at 180°) such that game can no longer accurately represent the engine in the designer. Such is the issues using the tinker panel sometimes.

    +1 7 months ago
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    @Toinkove I just cant see that happening, realistically how much gas would that small combustion chamber on the left create and then how fast would those gasses have to fly out to create so much thrust.


    I looked closer and changing the throat size affects the mass flow rate, so the large nozzle engine has a ton of fuel flowing into it to alow the masive throat to work.

    7 months ago
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    353 Toinkove

    Well you mean cause the combustion chamber is smaller? Given its nozzle throat size is a whopping 5 times that of the engine next to it, and that increasing troat size increases thrust by allowing more of the exhaust to escape out of the nozzle (or at a faster rate). It makes sense. My guess is that it is allowing those gasses to escape so fast (again 5 times as fast) that it doesn’t need a very large combustion chamber like the others have. This is my initial intuition….

    7 months ago

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