Calculating Density of Gas from Combusted Solid w/ Known Wt, Pres, Vol

In summary, the speaker is asking for help in finding the density of gas in a firearm's barrel after combustion. They have some known information, such as the weight of the propellant, volume of the barrel, pressure and temperature, and are considering using the ideal gas law to calculate the density. However, they are unsure if this is the correct approach and are open to suggestions for other models to use. They mention that this is part of a larger problem related to recoil and compensation.
  • #1
tjhj
2
0
Hello,
Thank you all for the help here.

Here we go, I have a known solid weight start of the propellent. I know the PSI of a known volume chamber(After combustion) and Temperature, can I find density?

So example
Bullseye powder has a load of 0.336954332 grams (5.2 grains)
The volume of the barrel is 0.39591921 in3
The pressure at this point is approx. 29,000 psi
Burn temperature = 2100k

I am thinking because the known mass of the air in the chamber, plus the mass of the powder can be used for the total mass in the density of the ideal gas equation. [itex]\rho[/itex] = MP/RT

Is this assumption correct? Will there be a substantial difference if I did not use the ideal gas law? I don't have the slightest clue what model would be appropriate to figure this as a "real" gas. Any suggestions?

This might make more sense in what it relates to. This is related to firearms and reloading. I am trying to figure out the density of the gas in the barrel just before it leave the chamber. This is part of a larger problem having to do with recoil and compensation, but this simple part I just can not seem to make connect.
 
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  • #2
tjhj said:
Hello,
Thank you all for the help here.

Here we go, I have a known solid weight start of the propellent. I know the PSI of a known volume chamber(After combustion) and Temperature, can I find density?

So example
Bullseye powder has a load of 0.336954332 grams (5.2 grains)
The volume of the barrel is 0.39591921 in3
The pressure at this point is approx. 29,000 psi
Burn temperature = 2100k

I am thinking because the known mass of the air in the chamber, plus the mass of the powder can be used for the total mass in the density of the ideal gas equation. [itex]\rho[/itex] = MP/RT

Is this assumption correct? Will there be a substantial difference if I did not use the ideal gas law? I don't have the slightest clue what model would be appropriate to figure this as a "real" gas. Any suggestions?

This might make more sense in what it relates to. This is related to firearms and reloading. I am trying to figure out the density of the gas in the barrel just before it leave the chamber. This is part of a larger problem having to do with recoil and compensation, but this simple part I just can not seem to make connect.
Using the ideal gas law is not valid at 2000 bars.
 

1. What is the formula for calculating density of gas from combusted solid with known weight, pressure, and volume?

The formula for calculating density of gas from combusted solid with known weight, pressure, and volume is d = (m * P) / (V * R * T), where d is the density, m is the mass of the solid, P is the pressure, V is the volume, R is the ideal gas constant, and T is the temperature (in Kelvin).

2. How do you determine the mass of the solid in the calculation?

The mass of the solid can be determined by weighing it on a scale before the combustion process. It is important to record the mass in the correct units (such as grams or kilograms) to ensure accurate calculations.

3. What is the ideal gas constant and how is it used in the calculation?

The ideal gas constant (represented by the symbol R) is a constant value that relates the properties of an ideal gas, such as pressure, volume, and temperature. It is used in the calculation to convert the units of pressure and volume to the correct units for density (usually in kg/m^3).

4. Can the temperature be measured in Celsius or Fahrenheit in this calculation?

No, the temperature must be measured in Kelvin in this calculation. This is because the ideal gas law, which includes the ideal gas constant, uses Kelvin as the unit for temperature. To convert from Celsius to Kelvin, simply add 273.15 to the temperature in Celsius.

5. Is this calculation applicable to all types of gases?

Yes, this calculation is applicable to all types of gases as long as the ideal gas law can be applied. This means that the gas must be at a constant temperature and pressure, and must behave as an ideal gas. If the gas deviates significantly from ideal behavior, the calculation may not be accurate.

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