Cylinder Compression: Pressure & Temperature Change

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    Compression Cylinder
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Discussion Overview

The discussion revolves around the thermodynamic principles governing the compression of a cylinder, specifically focusing on the relationship between pressure, temperature, and volume changes. Participants explore scenarios of both adiabatic and irreversible compression, seeking to understand how these processes affect the thermodynamic properties of the system.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification

Main Points Raised

  • One participant notes that while thermodynamics indicates that compression can increase both pressure and temperature, there is no single law that provides both changes based on volume, initial temperature, and initial pressure.
  • Another participant suggests that in the case of adiabatic reversible compression, both final pressure and final temperature can be determined.
  • It is mentioned that during irreversible compression, if the external pressure is controlled, the work done can be calculated, allowing for the determination of final equilibrium temperature and pressure.
  • Several participants express interest in resources for further reading on the reversible case of compression.

Areas of Agreement / Disagreement

Participants do not reach a consensus on a specific method to calculate pressure and temperature changes during compression, indicating that multiple approaches and models are being considered.

Contextual Notes

The discussion highlights the complexity of thermodynamic calculations in real-world scenarios, particularly the assumptions made regarding adiabatic versus irreversible processes and the control of external pressures.

Who May Find This Useful

This discussion may be useful for students and professionals interested in thermodynamics, particularly those studying engine theory and the principles of heat transfer during compression processes.

Pau Hernandez
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Hello,

according to thermodynamics the compression of a cylinder can both increase pressure and increase temperature. Unfortunately there is no law that gives us boh presure and temperture change given the change of volume, previous temperature and previous pressure? Usually we do either assume that pressure or temperature remains constant. Suppose the cylinder is isolated. What happens in a real world scenario to the pressure and temperature? How am I able to properly calculate the changes?
 
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If it's an adiabatic reversible compression, you can determine both the final pressure and the final temperature. If an irreversible compression is carried out in such a way that the extrernal pressure is controlled during the piston motion, the work can be determined and the final equilibrium temperature and pressure can be determined.
 
I appreciate the answer, sir. Any resources I can read up on the reversible case?
 
Pau Hernandez said:
I appreciate the answer, sir. Any resources I can read up on the reversible case?
Fundamentals of Engineering Thermodynamics, Moran et al.
 
introduction to thermal physics written by kittel
 

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