Air pressure changes in a vessel as the vessel volume increases

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Homework Help Overview

The discussion revolves around the behavior of air pressure in a sealed pressure vessel as its volume changes, specifically examining the relationship between pressure and volume in the context of pneumatic systems.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants explore the implications of increasing the volume of a pressure vessel on air pressure, questioning whether the pressure would halve if the volume is doubled. There are inquiries about the graphical representation of pressure change and the nature of the relationship between pressure drop and volume reduction.

Discussion Status

Some participants have suggested researching the Ideal Gas Law and its applicability to the scenario, while others have noted the complexity of real gas behavior at certain pressures and temperatures. The discussion includes various interpretations of the problem without reaching a consensus on the specific equations or methods to apply.

Contextual Notes

Participants have pointed out the absence of temperature information and the potential implications of assuming ideal gas behavior under the given conditions. There is also a mention of the need for self-sufficiency in finding answers, reflecting the forum's educational approach.

shotdove
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Homework Statement
Pneumatics
Relevant Equations
Unknown
As an example, you have a 100-gallon capacity sealed pressure vessel containing 100 psi of air pressure. What is the change in air pressure as the vessel volume is increased? If the volume is doubled is the pressure reduced to 50 pounds psi. On a graph, is the reduction rate a straight line? Is the pressure drop a percentage of the reduction in volume? What would the formula be for answering this question? Thank you
 
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Hello,
:welcome:

Here at PF we promote self-sufficiency ! Just google pressure versus volume and out comes the answer !

:smile:

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shotdove said:
Homework Statement: Pneumatics
Relevant Equations: Unknown

As an example, you have a 100-gallon capacity sealed pressure vessel containing 100 psi of air pressure. What is the change in air pressure as the vessel volume is increased? If the volume is doubled is the pressure reduced to 50 pounds psi. On a graph, is the reduction rate a straight line? Is the pressure drop a percentage of the reduction in volume? What would the formula be for answering this question? Thank you
Truthfully, it depends on the nature of the expansion. I assume you have not examined the Ideal Gas Law in any detail (or perhaps not at all)?
 
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BvU said:
Hello,
:welcome:

Here at PF we promote self-sufficiency ! Just google pressure versus volume and out comes the answer !

:smile:

##\ ##
Perfect, thank you.
 
BvU said:
Hello,
:welcome:

Here at PF we promote self-sufficiency ! Just google pressure versus volume and out comes the answer !

:smile:

##\ ##
Perfect. Thank you, and my Mom said thank you very much for being so helpful.
 
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shotdove said:
Perfect. Thank you, and my Mom said thank you very much for being so helpful.
You are most welcome. That's what PF is for.

Next step could be the ideal gas law

##\ ##
 
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There are many different state equations relating Pressure Temperature , Volume and density of gas. The ideal gas law is just one of them.

Not sure if the air behaves as ideal gas at 100Psi and at the given temperature (btw you omit the Temperature, not that it matters if we are given that air behaves as ideal gas for this problem).
 
Delta2 said:
Not sure if the air behaves as ideal gas at 100Psi and at the given temperature (btw you omit the Temperature, not that it matters if we are given that air behaves as ideal gas for this problem).
An ideal gas with a non-zero density will have its temperature affected by an adiabatic expansion.
 
Let's not make things more complicated than needed to help the OP ...

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