i set up a TVR-1 in a 1100mm steam tug w 75 mm prop from a 100mm diam. centre flue gas fired boiler, and it throws a rooster tail on full steam !!
we de proped back to a 50mm brass prop
I am happy w the little, we get about 25 minutes on the water per run and pressure is about 25 psi on load.
this not theory TVR-1 in this model , as we went for boiler capacity , and dont use a feed pump
this is not theory, but real run figures
as w all steam , it is necessary to actually build it and try it , no one rule for all models , but a starting point