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A water rocket is a type of model rocket using water as its reaction mass. The pressure vessel (the engine of the rocket) is constructed from thin plastic or other non metallic materials (usually a used plastic soft drink bottle) weighing 1,500 grams or less. The water is forced out by compressed air. It is an example of Newton's third law of motion.

Numerical Analysis

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Numerical Analysis

Post by JMost » Sat Aug 25, 2018 11:55 am

I am currently trying to create a theoretical model (simulator) to describe the altitude that a water rocket can reach for a University project.

I am in the process of trying to mathematically describe the transient flow of water through the bottle with an initial pressure and, of course, describing the gravitational work done on the water.

If anyone knows where i can find a similar model/ equations that i can program into MatLab to compare to my experimental results it would be a massive help!

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Re: Numerical Analysis

Post by anachronist » Sat Aug 25, 2018 1:09 pm

You wouldn't be the first.

I wrote a series of articles about this, as well as created a spreadsheet that performs the numerical analysis. You can find the links on this page: http://www.nablu.com/p/water-rocketry.html

If you use any of it, I would appreciate attribution in your project report. This took me several months of work to put together.

I tried to keep the math at the algebraic level. If you want something that goes into differentiation and integration, see this and related articles: https://www.et.byu.edu/~wheeler/benchtop/thrust.php

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