Heat transfer in a thermodynamic process occurs when thermal energy moves from one system or part of a system to another due to a temperature difference. The fundamental ways heat transfer happens are:
- Conduction
- Transfer of heat through a solid or between materials in direct contact.
- It happens via microscopic collisions and vibrations of molecules and free electrons within the material.
- Example: Heat traveling along a metal rod when one end is heated.
- Convection
- Transfer of heat by the physical movement of a fluid (liquid or gas).
- Can be natural (due to buoyancy differences caused by temperature variations) or forced (using pumps or fans).
- Example: Warm air rising above a heater.
- Radiation
- Transfer of heat through electromagnetic waves, primarily infrared radiation.
- Does not require a medium, so heat can transfer through a vacuum (like sunlight reaching Earth).
- Example: Heat felt from the sun or a fire.
