Hi There I'm wokring on a miniature steam car ~0.7kg. I've decided that I would like to investigate the feasibility of propelling the car with a steam jet. So I found a couple of equations that work on the velocity of the exhaust. Equation 1) De Laval nozzel equation for the velocity of the steam at the nozzel outlet, and 2) Ideal Rocket equation which takes the steam velocity from equation (1) to give the change in velocity of the car. Using these two equations I was able to get an estimate of acceleration and velocity of the car given fueled mass of car, and internal and external boiler pressure. Anyway, I believe that the figures are possible and that finally they depend only on the mass flow rate, which depends on the nozzell size and boiler pressure. I'm having difficulty finding the right way to determine boiler pressure given that it has a single outlet and amount of heat input. Any advice would be much appreciated.