Thermodynamic System Notes

Thermodynamic System

Definition

• A thermodynamic system is a definite quantity of matter under focus for thermodynamic analysis, studying changes in properties due to the exchange of energy in the form of heat and work.

Components of a Thermodynamic System

• System: The part we focus on for analysis.
• Surrounding: Everything external to the system.
• Boundary: An envelope separating the system from its surroundings.
• Universe: The combination of the thermodynamic system and surroundings.

Types of Thermodynamic Systems

1. Open System

• Definition: Mass and energy can transfer between the system and surroundings.
• Most engineering devices are classified as open systems.
• Examples:
  • Internal combustion engines
  • Air compressors
  • Water pumps
  • Steam engines
  • Turbine engines

2. Closed System

• Definition: Mass remains constant within the system's boundaries, but energy can transfer between the system and surroundings.
• Examples:
  • Pressure cookers
  • Rubber balloons filled with air
  • Gas confined in a piston-cylinder assembly

3. Isolated System

• Definition: Neither mass nor energy transfer occurs between the system and its surroundings.
• Examples:
  • Thermos flasks
  • The universe

Boundaries and Their Types

• Real Boundary: Can be rigid or flexible.
• Imaginary Boundary (???)

Special Boundary Types

• Adiabatic Boundary: No heat exchange between the system and surroundings.
• Rigid Boundary: No work is permitted between the system and surroundings or vice versa.