For an ideal rocket with a characteristic velocity c 1500 m

For an ideal rocket with a characteristic velocity c* = 1500 m/see, a nozzle throat diameter of 20 cm, a thrust coefficient of 1.38, and a mass flow rate of 40 kg/sec, compute the chamber pressure, the thrust, and the specific impulse.

Solution

Effective exhaust velocity = thrust coefficient * characteristic velocity

= 1.38*1500

= 2070 m/sec

Thrust = Effective exhaust velocity * mass flow rate

Thrust = 2070*40

   = 82800 N

Specific impulse = Effective exhaust velocity/acceleration due to gravity(g)

= 2070/9.81

   = 211 sec