Characteristics of the propellant

To choose a propellant, you will watch some characteristics.

I told you the propellant in the last post that your rocket is powered by a chemical reaction between two chemicals.

More this chemicals are energetic, more your rocket will be fast or able take off with a heavier weight.

When it is burns, the propellant produces gas. These gas are expanded by the temperature produced by the combustion and are expelled through the nozzle providing thrust according to Newton's third law.

Temperature depends on the energy stored by the chemicals and released when combusting. So more energy, more temperature and more temperature equal more thrust.

There is also the burn rate of the chemicals. A high burn rate is preferred because more gas are created providing a greater thrust.

But, a higher burn rate means also your propellant will be used faster. This could result in your rocket not reaching the height you expected.

Some propellant produce a lot of smoke,
some less or even not.

This impacts the specific impulse, also with the engine design, it is noted Isp and expressed in seconds.

Simply put, Isp is the time your rocket will fly with the propellant. It is the amount of thrust divided by the weight of your rocket. More thrust and light weight equals to high Isp.

However if you want to speed up the combustion, you can use a catalyst. Catalyst is another chemicals that is mainly used in the solid-fueled rocket sector.

You just have to add a little amount of it in your solid propellant and it will burn faster.

Catalyst are generally metal-oxides like iron oxide or manganese oxide mixed with the propellant in an amount of about 2 - 3% weight.

Each propellant I will propose to make will be described in terms of performance (thrust, Isp, etc) along with the chemicals needed, their proportions and how to shape them from powder to a more convenient form for your engine.