Throat Exhaust Air Velocity For a Cold Gas Propulsion Rocket Engine Calculator

In a cold gas propulsion rocket engine, the term “cold gas” typically refers to the use of compressed gas, often at ambient temperature, as a propellant. This is in contrast to traditional rocket engines where combustion of propellants generates high-temperature exhaust gases.

Cold gas propulsion is often used for relatively simple and low-thrust applications, such as attitude control systems for satellites. Detailed engineering analysis and simulations are still conducted during the design process to optimize performance based on specific mission requirements.

The continuity equation is based on the principle of mass conservation, and Bernoulli’s equation expresses the conservation of energy.

The continuity equation is given by:

A1​⋅V1​=A2​⋅V2​

where:

• A1​ and A2​ are the cross-sectional areas at the nozzle entrance and exit, respectively,
• V1​ and V2​ are the velocities at the nozzle entrance and exit, respectively.

which gives

where,

• A₁ is the Cross-sectional area at the throat of the nozzle in m² 
• A₂ is the Cross-sectional area at the exit of the nozzle in m²
• V₁ is the Velocity of the exhaust gases at the throat in m/s
• V₂ is the Velocity of the exhaust gases at the nozzle exit in m/s