"Heat transfer is a discipline of thermal engineering that concerns the generation, use, conversion, and exchange of thermal energy (heat) between physical systems."
Transfer of thermal energy from a warmer object to a cooler object.
Thermodynamics: The study of energy and its transformations.
Temperature: A measure of the average kinetic energy of particles in a substance.
Heat capacity: The amount of heat required to raise the temperature of a substance by one degree.
Calorimetry: The measurement of heat absorbed or released during a chemical reaction or physical change.
Heat transfer: The movement of thermal energy from one object or substance to another.
Specific heat: The amount of heat energy required to raise the temperature of one gram of a substance by one degree Celsius.
Conduction: The transfer of heat through direct contact between materials.
Convection: The transfer of heat through the movement of fluids or gases.
Radiation: The transfer of heat through electromagnetic waves.
Phase changes: The transitions between solid, liquid, and gas states that involve a change in energy but no change in temperature.
Heat engines: Devices that convert heat energy into mechanical work or vice versa.
Entropy: A measure of the degree of disorder in a system or the amount of thermal energy that is unavailable to do work.
Internal energy: The sum of the kinetic and potential energies of particles in a system.
Laws of thermodynamics: Fundamental principles that describe the behavior of energy in closed and open systems.
Conduction: Heat transfer through direct contact between two objects.
Convection: Heat transfer through the movement of fluid or gas.
Radiation: Heat transfer through electromagnetic waves, such as from the sun or a fire.
Advection: Heat transfer through the movement of a fluid, such as in ocean currents.
Latent Heat: Heat absorbed or released during a phase change, such as melting or condensing.
Sensible Heat: Heat transfer that causes a change in temperature.
Gravitational Heat: Heat generated due to gravitational compression, such as in planets or stars.
Joule Heating: Heat generated due to the flow of an electric current.
Frictional Heating: Heat generated due to the rubbing of two objects.
Magnetic Heating: Heat generated due to the alignment of atomic or molecular magnets.
Chemical Heat: Heat generated by a chemical reaction, such as combustion.
Nuclear Heat: Heat generated by nuclear fusion or fission reactions.
Blackbody Radiation: Radiation emitted by objects due to their temperature, regardless of the material.
Synchrotron Radiation: Radiation emitted by charged particles moving in a curved path through a magnetic field.
Bremsstrahlung Radiation: Radiation emitted by charged particles decelerating in a strong electric field.
"Heat transfer is classified into various mechanisms, such as thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes."
"The mechanisms include thermal conduction, thermal convection, thermal radiation, and transfer of energy by phase changes."
"Engineers also consider the transfer of mass of differing chemical species (mass transfer in the form of advection), either cold or hot, to achieve heat transfer."
"While these mechanisms have distinct characteristics, they often occur simultaneously in the same system."
"Heat conduction, also called diffusion, is the direct microscopic exchanges of kinetic energy of particles (such as molecules) or quasiparticles (such as lattice waves) through the boundary between two systems."
"When an object is at a different temperature from another body or its surroundings, heat flows so that the body and the surroundings reach the same temperature."
"Such spontaneous heat transfer always occurs from a region of high temperature to another region of lower temperature, as described in the second law of thermodynamics."
"Heat convection occurs when the bulk flow of a fluid (gas or liquid) carries its heat through the fluid."
"All convective processes also move heat partly by diffusion, as well."
"The flow of fluid may be forced by external processes, or sometimes (in gravitational fields) by buoyancy forces caused when thermal energy expands the fluid."
"The latter process is often called 'natural convection'."
"The former process is often called 'forced convection'."
"Thermal radiation occurs through a vacuum or any transparent medium (solid or fluid or gas)."
"It is the transfer of energy by means of photons or electromagnetic waves governed by the same laws."