Conduction of Heat through a Material

In summary, the problem involves calculating the heat per second per square meter that is conducted through a combination of ice and aluminum with specified temperatures and thermal conductivities. Using the equation for heat conduction through a material, the interface temperature can be found and used to solve for the heat flux. The resulting answer should be in J/(s*m^2).
  • #1
Jared944
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Homework Statement



.005 m of Ice is in contact with .0015 m of Aluminum. The temp of the Ice is -10.0 degrees C, and the temp of the Aluminum is -25.0 degrees C.

I need to calculate the heat per second per square meter that is conducted through the Ice - Aluminum combination

Homework Equations



The equation for the conduction of heat through a Material is (see attachment) Q= ((kA Change in T)t)/L

I know that the answer needs to be in J/(s*m^2), but I am unsure how to get to that point.

Thanks for any help!

Jared
 

Attachments

  • formula.gif
    formula.gif
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  • #2
I am assuming that the temperature is -10 C at the side of the ice away from the aluminum and the temperature is -25 C at the side of the aluminum away from the ice. The thermal conductivity of the ice is 2.34 W/m-K and the thermal conductivity of aluminum is 237 W/m-K in this temperature range. If T is the interface temperature between the ice and the aluminum, then $$q=2.34\frac{(-10-T)}{0.005}=237\frac{[T-(-25)]}{0.0015}$$where q is the heat flux.

If we solve for the interface temperature T, we obtain -24.956 C. This is very close to the aluminum temperature on the far boundary. Substituting into the equation gives a value of 7000 W/m^2 for the heat flux q.
 

1. What is conduction of heat through a material?

Conduction of heat through a material is the transfer of thermal energy from one molecule to another within a solid, liquid, or gas. This occurs through direct contact between the molecules, as they vibrate and pass on their energy to neighboring molecules.

2. What factors affect the rate of conduction?

The rate of conduction is affected by several factors, including the type of material, its temperature, the surface area, and the thickness of the material. Materials with higher thermal conductivity, higher temperature, larger surface area, and thinner thickness will have a higher rate of conduction.

3. How is heat transferred through different materials?

In solids, heat is transferred through conduction, while in liquids and gases, heat is transferred through convection and radiation. Conduction occurs in all materials, but the rate of transfer varies depending on the material's properties.

4. How does conduction differ from convection and radiation?

Conduction is the transfer of heat through direct contact between molecules, while convection is the transfer of heat through the movement of fluids, and radiation is the transfer of heat through electromagnetic waves. Conduction requires a medium, while convection and radiation can occur in a vacuum.

5. How can conduction be prevented or reduced in materials?

Conduction can be prevented or reduced by using materials with low thermal conductivity, such as insulators. Additionally, increasing the thickness of the material or reducing its surface area can also decrease the rate of conduction. In some cases, reflective coatings or barriers can also be used to reduce the transfer of heat through conduction.

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