[mihaipruna]

I'm trying to build a mathematical model of something like Heron's Aeolipile:
http://en.wikipedia.org/wiki/Aeolipile
I'd like to know, based on a known heat flux, the pressure and temperature attained in the container.
I assume as water boils, and the control volume loses mass and energy through the exhaust, the pressure and temperature of the vapors will stabilize.

Assuming pool boiling, nucleate regime, the equation of the heat flux contains both the saturation temperature and the surface temperature. However, as more heat is pumped into the system (the exhaust is small), the Tsat changes. So , even knowing the heat flux, I still have two unknowns, the surface temperature and the saturation temperature.

What kind of pressure increase in the vessel and what steam mass outflow should I get once it reaches a steady state boil?
How would I calculate that?

[kamakura117]

The next part is to finish up your control volume. You have an environment at STP and a nozzle (or two). From a basic fluid mechanics text, you can determine the thrust and choke velocity of the steam as a function of the nozzle inlet pressure and the mass flow rate of the steam via conservation of momentum. You can then iterate on the saturation temperature to meet conservation requirements on mass and energy, where, at steady-state you know that total steam mass flow = heating rate/enthalpy of vaporization.

[mihaipruna]

thank you for the response, that is kind of what I ended up doing, in Excel with VBA macros