How To Make A Model Rocket Engine

Building a model rocket engine at domicile.

Rocket engines are currently the most efficient method of getting off of the planet's surface. For space exploration companies like SpaceX and Blue Origin, designing the most efficient engine is the key to keeping their reusability status. Only just how hard is information technology to build one of these devices?

In this replicate, I'thousand going to effort to build a elementary model of a rocket engine that is used by diverse private infinite companies.

A Little Bit About Rocket Engines…

So how do rocket engines work?

Rocket engines are devices used to control a series of explosions, getting a payload from Point A to Signal B through the earth'southward gravity. The serial of explosions generate thrust, the force that pushes our rocket away from the Earth.

What makes up a rocket engine?

Liquid fuel engine diagram, showing the basic principle of mixing fuel and oxidizer.

Simply, rocket engines are fabricated up of fuel and oxidizer. The fuel and oxidizer are combined and ignited to produce large quantities of thrust (The series of explosions). The thrust can become full-bodied into a unmarried point (Simply a small pigsty for the hot explosion gasses to escape), assuasive the controlled explosion to simply direct the rocket to its destination.

What types of rocket engines are out there?

The three types of chemical rocket engines are Liquid, Solid, and Hybrid.

Liquid engines: Both fuel and oxidizer are stored in tanks.
Solid engines: Fuel and oxidizer are mixed into a solid.
Hybrid engines: Half solid, one-half liquid.

The Advantages/Disadvantages Of Each Type:

Liquid Engines:

Wait at how complicated the design of this liquid-fueled F1 engine!

Have the virtually controllability out of any other engine type.
The most efficient engines, cheers to their controllability.
Nearly expensive due to their complexity.

Solid Engines:

Solid fuel engines are made upwards of a tube and a nozzle, pretty uncomplicated.

Can generate more thrust over shorter periods.
Super simple pattern, super inexpensive to build.
Not very easy to control, making them less efficient.

Hybrid Engines:

Just like a solid engine, just the fuel and oxidizer are separated.

Combine the simplicity of solid motors (Cheaper) and controllability/safety of liquid motors.
More than efficient than solid-fuel motors.
Still less efficient than liquid-fuel motors.

So, we are going to build a model hybrid engine!

We desire something that is easier to control and simple to build, so a hybrid engine seems similar the way to go (I dearest liquid motors, merely they are just way also unsafe to work with).
Our hybrid engine will use solid fuel and "liquid" oxidizer (I'm using a gas crusade' liquid oxygen is expensive!).
Our fuel can be almost annihilation! As long every bit it's flammable and tin fit inside the engine piping.

The engine volition too be made of contumely, which isn't very heatproof. Simply, the simply part that gets affected most is the nozzle. This function tin can easily be replaced with more oestrus resistant metals such as steel, only let's but try contumely for now.

Parts Of Our Engine:

Our hybrid engine consists of three unproblematic components:

A valve for controlling the pressurized oxidizer tank.

A combustion chamber, storing the fuel in an elongated tube.

A nozzle for concentrating and directing the flow of frazzle gases.

To become these components, I had to recall of diverse shapes for the parts. The valve for the oxygen was simple, it just needed to connect the oxygen tank to the residual of the engine. The combustion chamber needs to shop the fuel, a long tube should requite space for the combustion chamber inside the engine. The nozzle needs to condense the hot gasses into a smaller space, directing the menstruum and increasing the engine pressure.

The fuel and oxidizer of the motor will also exist shop-bought components…

The Oxidizer: A welding oxygen tank.

Bought from a hardware store, these tanks are inexpensive and modular. They comprise 100% pure oxygen, perfect for burning that fuel!

The Fuel: Paper products.

Paper-thin tubing seemed to work the best, it could be conveniently sized and provided plenty material for the reaction within the combustion sleeping accommodation. There were other options for fuel, but I was just also chicken to endeavor them!

How we'll start the engine:

A unproblematic fuse or a modest piece of forest tin can make this incredibly easy. I only had to light the tip of the fuse with a safety lighter before briskly walking abroad from the engine itself and turning the oxygen valve on.

The Engine Test:

The test-firing wasn't very impressive thrust-wise (We couldn't even measure it if we wanted to!), but the flame looked cracking!

A few things I learned…

Fueling the fire is like shooting fish in a barrel, moving the payload is hard.

Aye, anything flammable can exist used every bit a rocket fuel… However, there's a reason why nosotros don't use paper in whatever of our mod-twenty-four hour period rockets.

Fuel and oxidizer make up fourscore percent of the rocket's mass. Because of how much space the fuel takes up, efficiency is key to getting the other twenty percent out of globe's gravity. So fuel must be extremely reactive, creating larger explosions with a smaller mass. Many fuels possess this capability, simply they have their downsides too.

ii. Practiced fuel comes at a price.

Skilful fuel can be corrosive, flammable, toxic, or even all three. Even simple elemental fuels such as Hydrogen tin easily impale many every bit it is highly reactive with its environment. The material I used isn't very reactive with its environs, it should have a similar free energy density (Probably less) to the wood in this diagram, which has less than half the energy density of common rocket fuels and even less energy than pure Hydrogen (One of the all-time rocket fuels since it has a college ratio between weight and energy density).

Where Liquid Fuel Shines:

If a rocket is designed to carry more cargo over large distances, liquid engines fare much better as liquid fuels tin can have a much higher energy density than their solid counterparts.

3. Even some control is greater than none.

The nearly mutual rocket motors used by amateur rocket enthusiasts apply solid fuel. Solid fuels are inexpensive and like shooting fish in a barrel to utilize, but they are also really difficult to command. On a larger calibration, solid engines take a higher run a risk of interacting with their environs as the fuel and oxidizer are in one place, this can be very harmful to those working with these engines (Who wants decease by rocket fuel?). A hybrid engine is slightly more complicated on the calibration of difficulty among rocket engines, utilizing the controllability of a liquid engine but also the simplicity of a solid booster. There is more safety with hybrid motors equally the fuels and oxidizers are separately stored, making information technology easier to build the rocket without getting yourself killed.

What'due south Side by side For Hybrids?

Various space tourism companies will go on to utilize hybrids as they're extremely reliable and safe for their price. Virgin Galactic is one of the best examples for hybrid fuel usage, equally they just accept to behave pocket-size cargo (Tourists) into the border of space.