Rockets Part 3: Propellant

Rockets Part 3: Propellant

What gives a Rocket Thrust?

• Rockets move due to Newton's Third law

  • The action of the fuel combustion causes the reaction of a rocket moving forward

• ​The combustion of the fuel requires large amounts of energy

• Propellant:​ The energy that moves an object that comes from a chemical reaction

  • Cars use Gas as a propellant​

Parts of Propellant

• Liquid Propellant is made up of two parts that are separated into different tanks until the reaction needs to take place

  • Fuel: The main substance that is "burned"​

  • Oxidizer: The substance that provides oxygen to a reaction

    • Oxygen is needed for combustion

Parts of Propellant

• Solid Propellant only has the fuel

  • Examples of solid propellants: Coal, wood, wax​

  • Solid Propellant Rockets have star shaped holes at the bottom to increase amount of surface area of the propellant exposed

    • As the combustion occurs, the shape melts into a circle and increase the surface area, allowing the fuel to burn more efficiently in space

Open Ended

For a solid propellant fuel tank, why wouldn't you just start with a round hole in the beginning?

Propellant in Rockets

• Ideally any rocket is about 90% propellant

  • tanks and engines= 4%

  • Payload= 6%

    • Payload is what the rocket is carrying

• As a rocket burns it's Fuel, the mass decreases, as does the acceleration

Combustion Reactions

• Combustion reactions are the reactions between oxygen and another chemical that result in carbon dioxide and water as the products

  • Generate energy as light and heat​

  • Reactants tend to by hydrocarbons

    • Elements made up of hydrogen and oxygen

  • Many of our engines rely on combustion reactions

  • The Hindenberg (1937): An airship that used hydrogen as a fuel source

    • When landing the hydrogen reacted with the carbon in a combustion reaction

Multiple Choice

This is the part of a propellant that is used up

• Fuel

• Oxidizer

• Feed

Multiple Choice

What element increases the reaction that occurs in the combustion of fuel

• Hydrogen

• Helium

• Nitrogen

• Oxygen

Multiple Choice

This is the part of a candle that serves as fuel

• The Wax

• The wick

Multiple Choice

What type of reaction provides thrust for rockets?

• Synthesis

• Decomposition

• Displacement

• Combustion

Multiple Choice

All combustion reactions have this as a reactant

• Carbon

• Water

• Helium

• Hydrogen

• Oxygen

Fill in the Blank

If you have a 100 kilogram rocket, what is the approximate mass of the propellant?

Fill in the Blank

You want to move a 25 kilogram box using a rocket. How big should your rocket be? Round to 2 Decimal Places

Fill in the Blank

If a satellite weighs 5 tons, and the tanks, engines, and body of the rocket weigh 5 tons, how many tons would the propellants weigh?

Fill in the Blank

Challenge: If the total rocket weighs 200 tons, how much of that weight should be propellant?

Multiple Select

Which of the Following are examples of Combustion Reactions? Click all that apply

• CH₄ + 2 O₂ → CO₂ + 2 H₂O

• 2 H₂ + O₂ --> H₂O

• 2 C₄H₁₀ +13 O₂ → 8CO₂ +10H₂O

• 3 H₂(g) + N₂(g) → 2 NH₃(g)