# Thermal Conductivites between two dissimilar metals

• Lets Get Physical
In summary, the problem involves determining the thermal energy at 1 meter from a heat source for material X, with and without contact with material Y, in both a vacuum and ambient air at STP. The thermal conductivity values for X and Y are given, as well as the distances between them and the heat source. The question also considers the potential effects of conduction between X and Y and thermal radiation.
Lets Get Physical

1. Homework Statement

I've been failing to find examples dealing with "longitudinal" thermal conductivity and how two objects in contact with each other would affect the heat flow compared to not being in contact at all.

Problem: Given the following information, determine the thermal energy at 1 meter from the heat source for material X for the two cases 1) Where material X is not contact with material Y 2) Where material X and Y are in contact as shown. For both cases, first assume materials are in vacuum, then assume there are in ambient air at STP (273 K).

## Homework Equations

Thermal Conductivity
X: 2,000 W/(m K)
Y: 50 W/(m K)

d1 = 0.00001 m
d2 = 1 m

Heat Source
q = 100 W

Heat Transfer Coefficient
Air: 10 W/(m^2 K)

## The Attempt at a Solution

What I am struggling with is whether the conduction between X and Y would essentially "shorten" the conduction of material X itself. I am also unsure if thermal radiation would come into play. Any help is appreciated!

Lets Get Physical said:
whether the conduction between X and Y would essentially "shorten" the conduction of material X itself.
"Series resistance" versus "parallel?"

## 1. What is thermal conductivity?

Thermal conductivity is the ability of a material to conduct heat. It is measured in watts per meter Kelvin (W/mK) and indicates how much heat can be transferred through a material in a given amount of time.

## 2. How does thermal conductivity differ between two dissimilar metals?

The thermal conductivity between two dissimilar metals can vary significantly due to differences in their molecular structures and composition. In general, metals with a higher density and lower atomic mass tend to have higher thermal conductivity.

## 3. What factors affect the thermal conductivity between two dissimilar metals?

The thermal conductivity between two dissimilar metals can be influenced by factors such as temperature, pressure, and the presence of impurities or defects in the materials. The composition and microstructure of the metals also play a role in determining their thermal conductivity.

## 4. Why is thermal conductivity important in industrial applications?

Thermal conductivity is important in industrial applications as it affects the efficiency and effectiveness of heat transfer processes. Materials with high thermal conductivity are often used in heat exchangers, refrigeration systems, and other thermal management systems.

## 5. How is thermal conductivity measured between two dissimilar metals?

Thermal conductivity between two dissimilar metals can be measured using techniques such as the hot wire method, guarded hot plate method, or laser flash method. These methods involve applying heat to one side of the materials and measuring the temperature change on the other side to calculate the thermal conductivity.

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