I am doing the math required to find the thrust of a rocket engine (more specifically backwards, I have the thrust required and I am designing the engine).
In my looking over the equations I have found on the NASA website:
http://spaceflightsystems.grc.nasa.gov/education/rocket/rktthsum.html
$$F={\dot {m}}*Ve+(Pe-Po)*Ae$$
In this equation: ${\dot {m}}$ = Mass flow rate $Ve$ = Exit velocity $Pe$ = Exit pressure $Po$ = Chamber pressure $Ae$ = Exit area
It seems to me that if the ambient pressure and exit pressure are equal, that the equation would just be:
$F={\dot {m}}*Ve$
Would this be the correct because $(Pe-Po)*Ae $ is then zero?
