Modeling Pressure Escape from a 8g CO2 Cartridge

Hey, I was working on a CO2 car project in which I need to know the pressure outwards force of a 8g CO2 cartridge (link: as a function of time. I tried doing the physics by hand using ideal gas law and graham’s law, but I don’t have another gas as comparison. I also tried using mass flow rate, but I don’t know how to calculate volumetric flow rate or mean velocity.

I have a rudimentary CAD model of the cartridge as well as all the dimensions and the amount of CO2 inside, but I don’t know how to model pressure of a gas escaping from a container on Simscale.

Could someone show me how to create a simulation for this problem?


Hi there,
Thank you for posting on the forum!
This sounds like an interesting project. I have a few suggestions:

  • Set the inlet boundary condition to represent the CO2 cartridge. Since you’re interested in the pressure outwards force, you might specify the pressure inside the cartridge and the mass flow rate of CO2 gas exiting through the nozzle.
  • In this case, a transient solver might be suitable since you’re interested in how pressure changes over time as gas is released.
  • You can also calculate the outward force exerted by the escaping CO2 gas by integrating the pressure over the area of the nozzle.