Created By : Naaz Fatima

Reviewed By : Phani Ponnapalli

Last Updated : Apr 10, 2023


Use this free Thermal Conductivity Calculator to compute the heat flux through an object or thermal conductivity of a material quickly. You have to provide the data in the required input fields and hit the blue colour calculate button to avail the result in a short span of time.

Given
Distance (Δx)
Temperature difference (ΔT)
Heat flux (q)

How to Find Thermal Conductivity?

Following are the guidelines to be followed to compute the thermal conductivity or heat flux of any material. Have a look at the simple steps and get the ouput.

  • Find thermal conductivity constant, distance and temperature difference.
  • Divide the change in temperature by change in distance.
  • Multiply the result by negative of thermal conductivity constant.
  • The product is called the heat flux.

What is Thermal Conductivity?

Thermal conductivity is the material ability to conduct or transfer heat. It is directly proportional to the distance of heat transfer and heat energy transferred to and inversely proportional to the change in temperature of the material. The unit of thermal conductivity is watts per meter kelvin.

You have to know the thermal conductivity to calculate the amount of heat energy transferred through it.

The formula to calculate the thermal conductivity is here

λ = (QL)/(AΔT)

Where,

╬╗ is Thermal conductivity

A is the area of the surface

L is the distance between two isothermal planes

Q is the amount of heat transferred

ΔT is change in temperature

Heat Flux

The amount of heat energy transferred every second per unit area is known as heat flux. You can calculate the heat flux using Fourier's law.

Fourier's law states that the negative gradient of temperature and the time rate of heat transfer is directly proportional to the area at right angles of the gradient through which the heat flows.

The heat flux as per Fourier's law is along the lines

q = -λΔT/Δx

Where,

ΔT is the temperature difference across the material

Δx is the distance of heat transfer

q is the heat flux

╬╗ is the thermal conductivity of a material

Example

Question: Find the thermal conductivity of a material, if one end of 0.22 m long metal bar is placed in steam and the other end is placed in ice. Given that 15x10-3 kg of ice metls per minute, later heat of the ice is 80 cal/kg and the cross-section of the metal bar is 7x10-4 m┬▓

Solution:

Given that

Length L = 0.22 m

Cross-sectional area A = 7x10-4 m┬▓

Amount of heat transferred Q = 15x10-3 x 80 x 1000 = 1200 cal

Change in temperature ΔT = 100 x 60

Thermal conductivity formula is λ = (QL)/(AΔT)

= (1200 x 0.22)/(7x10-4 x 100 x 60)

= 264/(4.2)

= 62.85

Therefore, thermal conductivity of the metal is 62.85 cal/ms┬░C.

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FAQ's on Thermal Conductivity Calculator

1. How to calculate the thermal conductivity of material using calculator?

You have to enter thermal conductivity constant, distance and temperature difference in the fields of the Heat Flux Calculator and press on the calculate button to get the thermal conductivity in a fraction of seconds.


2. What is meant by Thermal Conductivity?

Thermal conductivity is defined as the intrinsic ability of the material to transfer the heat. It is denoted by the symbol ╬╗ or k. The SI unit of heat flux is watts per meter Kelvin.


3. Define the heat flux?

The heat energy transferred every second per unit area is called the heat flux. The Fourier's law to define the heat fkux is q = -λΔT/Δx.


4. How does temperature effect on thermal conductivity?

If the temperature increases, then the pure metal electrical conductivity decreases. The thermal conductivity of metals shows little variance with the temperature increase.