Kirchhoff’s Law

What is Kirchhoff’s Law? To understand Kirchhoff’s law let us consider a small body of surface area As , emissivity ϵ, and absorptivity α at […]

Absorptivity, Reflectivity, and Transmissivity

A brief discussion on Absorptivity, Reflectivity, and Transmissivity of radiative heat transfer Everything around us constantly emits radiation (for heat transfer), and the emissivity represents […]

Blackbody Radiation

A body at a temperature above absolute zero emits radiation in all directions over a wide range of wavelengths. The amount of radiation energy emitted […]

Reynolds Number

The transition from laminar to turbulent flow depends on the surface geometry, surface roughness, free-stream velocity, surface temperature, and type of fluid, among other things. […]

Laminar Flow and Turbulent Flow

If you have been around smokers, you probably noticed that the cigarette smoke rises in a smooth plume for the first few centimeters and then […]

Thermal Diffusivity

The product ρCp, which is frequently encountered in heat transfer analysis, is called the heat capacity of a material. Both the specific heat Cp and […]

Energy Transfer

Energy transfer to or from a given mass by two mechanisms: heat Q and work W. An energy interaction is heat transfer if its driving […]

Application Areas of Heat Transfer

Heat transfer is commonly encountered in engineering systems and other aspects of life, and one does not need to go very far to see some […]

Dew-Point Temperature

Dew-point temperature If you live in a humid area, you are probably used to waking up most summer mornings and finding the grass wet. You […]

Isentropic Process

The entropy of a fixed mass can be changed by (1) heat transfer and (2) irreversibilities. Then it follows that the entropy of a fixed […]