Conduction , Mechanism of heat transfer .

Conduction :

- Conduction refers to the transfer of heat from one molecule to an adjacent molecule or from warmer object to a cooler object when the two objects are in direct contact with each other . Conduction needed matter and does not require any bulk motion of the matter .

-  heat conduction occurs at hot , rapidly moving or vibrating atom and molecule interact with nighboring atoms and molecules transferring some of their energy to these nighbouring particles .

- thermal conductivity is the property of the material to conduct heat and evaluated primarily in terms of Fourier's Law of heat conduction .

- heat is transferred by conduction when adjacent atom vibrate against one another or as electron move from one atom to another  .

-  Conduction id the most significance mean of heat transfer within a solid or between solid obejcts in thermal contact .

- fluid specially gaeses are less conductive  .

- the Process of heat transfer from one place top another place without the movement of the particle within the material is called conduction .

Example  : - heat transfer through metal conduction .

Types :

1.  Steady state Conduction :

 

-  it is the form of the conduction that happens when the temperature difference driving the conduction  is constant  . so that after an equilibrium time the spital distribution of temperature in the conduction conducting obeject does not change any further  .

- in steady state conduction the amount of heat entering a section is equal to the amount of heat coming out .

2. Transient Conduction :

-  Occurs when the  temperature within an object changes as a function of time .

Fourier's Law :

The Equation governing heat conduction along something of length (or thickness ) L and cross - sectional area A in a time T is : 

Q = KA dl Tt / L

Q = rate of heat transfer

dl T = Temperature Difference betwen two ends  .

K =  Constant 

t =  time .

A =  cross sectional area  .

L =  thickness .