- Home/
- GATE MECHANICAL/
- GATE ME/
- Article
What is Conduction Heat Transfer?
By BYJU'S Exam Prep
Updated on: September 25th, 2023
Conduction Heat Transfer or Thermal conduction is the transfer of internal energy within a body through tiny particle collisions and electron mobility. When molecules, atoms, and electrons collide, they transfer disordered tiny kinetic and potential energy, known as internal energy. Conduction heat transfer occurs in all stages, including solids, liquids, gases, and plasma; conduction is the transfer method of heat in these stages.
As per the Conduction heat transfer, heat naturally moves from a hotter to a cooler body. For example, heat is transferred from the hotplate of an electric stove to the bottom of a saucepan that is in contact with it. Conduction heat transfer explains why temperature variations within a body or between bodies diminish with time in the absence of an opposing external driving energy source, and thermal equilibrium is approached, with temperature becoming more uniform. Here we will read about the conduction mode of heat transfer and a few examples of conduction heat transfer in detail.
Download Formulas for GATE Mechanical Engineering- Heat Transfer
Table of content
What is Conduction Heat Transfer?
Thermal energy is transferred from one location with greater kinetic energy to another with lower kinetic energy. When high-speed particles collide with slow-moving particles, the slow-moving particles’ kinetic energy is increased.
Conduction Heat Transfer Meaning
The term conduction is sometimes referred to as hermal or heat conduction. Conduction heat transfer is a common heat transfer method involving physical contact.
Conduction Heat Transfer Definition
“The process of energy transmission from one medium particle to another with the particles in direct touch with one another.”
Conduction is the method of transfer of heat in solid bodies in contact. A temperature drop is generally observed at the interface between the two surfaces in contact. The presence of thermal contact resistance between the contacting surfaces is thought to be the cause of this phenomenon.
Download Formulas for GATE Mechanical Engineering – Refrigerating and Air Conditioning
Fourier Law of Conduction Heat Transfer
According to Fourier’s law, the area at right angles to the gradient through which the heat flows is proportional to the negative gradient of temperature and the time rate of heat transfer. The law of heat conduction is also known as Fourier’s law.
Differential Form Of Fourier’s Law
Fourier’s law is expressed in differential form as follows:
q=-k▽T
Where,
- q is the local heat flux density in W.m2
- k is the material’s conductivity in W.m-1.K-1
- ▽T is the temperature gradient in K.m-1
Conduction Heat Transfer Formula in One-Dimension Form
qx = -k dT/dx
Integral Form
∂Q/∂t = -k∮∮s▽T.dS
Where,
- ∂Q/∂t is the amount of heat transferred per unit of time
- dS is the surface area element
Download Formulas for GATE Mechanical Engineering – Thermodynamics
Conduction Heat Transfer Examples
The terms heat conduction, and thermal conduction are similar. When molecules heat up, they start to vibrate, transferring kinetic energy to other molecules they come into contact with. Let us now see the examples of conduction heat transfer. The following are the common examples of conduction in everyday life.
- You can warm up your back muscles using a heating pad. The pad delivers heat to the part of your body it is in contact with as it heats up.
- The heat from a hot beverage also heats up the cup. If you pick up a cup of hot coffee or tea, the cup will be hot, and your hands will feel it.
- If you are cold and someone holds your hand to warm you, heat is transferred from their body to yours.
- It will melt if you hold a chocolate candy in your palm long enough. Your hand’s heat is transferred to the chocolate.
- The iron is hot when ironing a piece of cloth, and the heat is transferred to the cloth.
- If you use poker to stoke a fire in the fireplace and then leave it in flames, the poker will become extremely hot.
- Sand has the ability to conduct heat. Walking on the beach on a hot summer day will warm your feet in this way.
- When walking on scorching asphalt or concrete, protecting your dog’s paws is critical. They transfer heat to your pet’s feet in the same way that they do to yours.
- Heat is produced by light bulbs. Your hand will be burned if you touch a light bulb turned on.
