Mixture Ratio for oxygen/propane in a rocket engine?

In summary, the Air/Propane mixture ratio for a pulse jet engine is 15 to 1, which can be calculated by dividing the mixture ratio of Oxygen/Propane (4.5 to 1) by the percentage of oxygen in air (21%). However, there is conflicting information in different sources about the mixture ratio for Oxygen/Propane, with one source stating it is 4.5 to 1 and another stating it is not available. It is important to carefully consider and verify information when working with potentially dangerous mechanical systems.
  • #1
gary350
253
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What is the Air/Propane mixture Ratio?

The Fuel Air Ratio of a Jet Engine is 15 to 1. This is for JP4.

What is the Fuel Air Ratio for Propane Gas?

I have learned the only difference between a rocket engine and pulse jet engine is the pulse jet runs on the oxygen that is in the air (30% oxygen + 70% nitrogen) while the rocket engine runs on pure oxygen. Many of the formulas for calculating the nozzle diameter etc. are the same for both types of engines. In order to do the calculation for a pulse jet engine running on propane I need to know the Air Fuel Mixture Ratio for and Air/Propane mixture.


Confliction information here.


Book #1. Propulsion Systems for Guided Missiles.

Mixture ratio for Oxygen/Hydrogen is 5.33 to 1.

Mixture ratio for Oxygen/Ethyl Alcohol is 1.5 to 1.

Mixture ratio for Oxygen/gasoline is 3.0 to 1.

Mixture ratio for Oxygen/Propane is 4.5 to 1.


Book #2. Liquid Fuel Rocket Engines.

Mixture ratio for Oxygen/Hydrogen is 3.5 to 1.

Mixture ratio for Oxygen/Methyl Alcohol is 2.2 to 1.

Mixture ratio for Oxygen/gasoline is 2.5 to 1.

Mixture ratio for Oxygen/Propane is Not Available.


I assume if for example since air is 30% oxygen I should be able to divide the Oxygen mixture ratio for a Rocket Engine by .3 to get the Air/Fuel Mixture Ratio for a Pulse Jet Engine. Is it correct to assume this?

The mixture ratio of Oxygen/Propane is 4.5/1 then the mixture ratio for Air/Propane should be 4.5/.3=15 or 15/1.

Is this correct?


The Fuel Air Ratio of a Jet Engine is 15 to 1.








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Last edited:
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  • #2
The percentage of O2 is 21 percent not 30 percent. If the 4.5 is correct, 4.5 / .21 equals 21.4.
 

1. What is the ideal mixture ratio for oxygen and propane in a rocket engine?

The ideal mixture ratio for oxygen and propane in a rocket engine is typically around 5:1, meaning there are 5 parts of oxygen for every 1 part of propane. This ratio allows for efficient combustion and maximum thrust.

2. Why is oxygen used in rocket engines instead of air?

Oxygen is used in rocket engines instead of air because it is a pure oxidizer, meaning it helps burn the fuel more efficiently. Air contains many other gases that can interfere with the combustion process and reduce the engine's performance.

3. Can the mixture ratio be adjusted during a rocket launch?

Yes, the mixture ratio can be adjusted during a rocket launch. This is done through the use of an adjustable valve that controls the flow of oxygen and propane into the combustion chamber. The mixture ratio may need to be adjusted in order to maintain the desired thrust and keep the engine running smoothly.

4. How does the mixture ratio affect the rocket's performance?

The mixture ratio plays a crucial role in determining the rocket's performance. An incorrect mixture ratio can result in inefficient combustion, which can lead to a decrease in thrust and potentially even failure of the engine. The ideal mixture ratio ensures optimal performance and maximum thrust.

5. Are there any safety concerns with the mixture ratio of oxygen and propane in rocket engines?

Yes, safety is a major concern when it comes to the mixture ratio of oxygen and propane in rocket engines. If the ratio is too lean (not enough oxygen), there is a risk of an incomplete burn and the buildup of unburned fuel, which can lead to explosions. On the other hand, a ratio that is too rich (too much oxygen) can also be dangerous as it can cause the engine to overheat. It is important to carefully monitor and maintain the correct mixture ratio for safe and successful rocket launches.

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