Thank you so much for your help, it is seriously appreciated.
I only have one more question and then I should be sorted. I am currently setting up a transient energy balance on the entire inner bottle control volume. So far i have:
The rate at which gravitational work is being done on the water...
I agree completely that the variation in velocity at a point in the bottle is considered negligible compared to the acceleration of the fluid approaching the nozzle. This is in fact what I did in my previous model. However, when I took this to my Professor, he did not appreciate any "assumptions...
The bottle is a standard 2L coke bottle (as restricted to in my mini-thesis project). The diameter is constantly changing, but for the sake of easy explaining i can use MatLab later to iterate each step at a different height. I am not sure of the ratio of water to air yet, as i was first wanting...
I am currently modeling the altitude that a water rocket can attain. In order to do this i am first modeling the the thrust phase.
Due to the water mass decreasing with time (the same goes for the pressure - it decreases over time as the water is expelled out of the nozzle).
This is an...