Velocity of Exhaust Gases At The Nozzle For a Cold Gas Propulsion Rocket Engine Using Specific Impulse Calculator

For a cold gas propulsion system, where a pressurized gas is expelled to generate thrust, the velocity of the exhaust gases at the nozzle exit can be calculated using a simplified form of the rocket equation. In the case of cold gas propulsion, the specific impulse (Isp​) is essentially the exit velocity of the gas. The formula is given by:

Where:

• V_exit is the change in velocity of the rocket (in meters per second, m/s).
• I_sp​ is the specific impulse of the rocket engine (in seconds, s).
• g₀ ​ is the acceleration due to gravity at the Earth’s surface (approximately 9.81 m/s²).
• m₀​ is the initial mass of the rocket (including propellant, air and structure, in kilograms, kg).
• m_f ​ is the final mass of the rocket (after propellant burnout, in kilograms, kg).