Thermodynamic Process

Definition of a Process

• Transformation from one state to another.
• In thermodynamics: transformation of a system from one equilibrium state to another.

Thermodynamic Process

• When a thermodynamic system changes states, involving changes in:
  • Temperature
  • Pressure
  • Volume
• Example: Piston and cylinder system with changing weights.
  • Initial state: Pressure (P1), Volume (V1)
  • Final state: Pressure (P2), Volume (V2)
• Energy transfer: Can occur into or out of the system.

Types of Thermodynamic Processes

1. Isothermal Process

• Definition: Temperature remains constant.
• Characteristics:
  • dT = 0 (initial and final temperature are the same).
• Example: Boiling water at a constant temperature.

2. Adiabatic Process

• Definition: No heat transfer occurs.
• Characteristics:
  • Perfectly insulated system.
  • Energy transfer occurs only as work.
  • DQ = 0 (no heat added or lost).
• Example: A frictionless piston cylinder enclosure.

3. Isochoric Process

• Definition: Volume remains constant.
• Characteristics:
  • dV = 0 (initial and final volumes are the same).
• Example: Boiling water in a closed vessel.

4. Isobaric Process

• Definition: Pressure remains constant.
• Characteristics:
  • dp = 0 (initial and final pressures are the same).
• Example: Boiling water at atmospheric pressure.

5. Cyclic Process

• Definition: System returns to its original state.
• Characteristics:
  • dE = 0, dH = 0 (net change in internal energy is zero).
• Example: Carnot cycle.

Other Important Processes

Reversible Process

• Definition: System and surroundings can be restored to initial state without changes in the universe.
• Example: Melting of ice cream.

Irreversible Process

• Definition: System and surroundings cannot revert to initial state.
• Example: Mixture of cement, sand, and water.

Note: The lecture emphasized on the fundamentals of thermodynamic processes, their definitions, and examples to illustrate the concepts.