Questions tagged [thermal-conductivity]
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12
questions
3
votes
0answers
55 views
Electrical and thermal conductivity of graphite
I was reading about carbon family where it was mentioned that electrical conductivity of graphite increases with temperature while thermal conductivity decreases.
However, I could not find a suitable ...
0
votes
1answer
26 views
How would a temperature profile in wall change if the rate of heat transfer increases
Given the system below, how would the temperature profile in the wall change if the heat transfer in Fluid II was very fast?
If the heat transfer in Fluid II is very fast, then the T-profile ...
1
vote
0answers
32 views
Derive expression for average heat flux in heat exchanger
The single-tube heat exchanger is used to increase the temperature of fluid
I from $T_{b1}$ to $T_{b2}$. The heating oil (fluid II) used
for this task enters at temperature $T_{02}$ and leaves at
...
1
vote
0answers
28 views
Simplifying temperature profile
I am given the temperature profile below and the two equations:
$$Q = (2\pi R_0)LU_0(T_{1\infty}-T_{2\infty})\tag1\label1$$
$$\frac{1}{U_0R_0} = \frac{1}{h_1R_0} +\frac{\ln(R_\mathrm a/R_0)}{k}+ ...
2
votes
1answer
78 views
Derive expression for heat flow from oil bath to metal sphere
A spherical ball of iron is put into a hot bath of oil. The iron ball is initially at a low temperature and heat transfer from the oil to the iron will increase the temperature of the iron ball.
...
0
votes
1answer
41 views
Temperature profile at steady state [closed]
Consider a solid wall consisting of three layers where the layers are of equal
thickness but made out of different materials: $\ce{Layer 1}$ is made out
of copper (high thermal conductivity), $\ce{...
3
votes
2answers
75 views
Determine heat flux from temperature profile
The heating
element and the insulator are of equal thickness L. Heat transfer in
the air film adjacent to the heater is assumed negligible.
I've noticed that I find these type of problem the ...
-3
votes
2answers
231 views
Pre-Hydrogen Feature On the Output Of a Gas Chromatography Thermal Conductivity Detector
A candidate for "dark matter", predicted and now apparently detected to have both a higher thermal conductivity and higher diffusion rate than H2 is purported in this PowerPoint Presentation file. ...
3
votes
2answers
147 views
Heat transfer through layered wall
An electrical heater is placed between two layers of insulation. The three layers (the heater and the two layers of insulation) have the same thickness. The figure below shows different temperature ...
3
votes
1answer
74 views
Equation for overall heat transfer coefficient
The heat flow (in $[\pu{J/s}]$) through the wall of a tube of length $L$ and inner radius $R_0$ is
$$Q = (2πR_0L)U(T_{1\infty} - T_{2\infty}),$$
where $T_{1\infty}$ is the bulk temperature ...
0
votes
1answer
1k views
Graphite: Thermal and electrical conductivity
I recently encounter this question:
Compare, while providing an explanation, the thermal and electrical conductivity of graphite to that of diamond.
Provided answer:
Graphite conducts electricity(...
10
votes
1answer
1k views
Why would a ~1 cm thick layer of argon be a significantly poorer conductor of heat than air?
In yesterday's new Periodic Video, Argon (new) - Periodic Table of Videos, after about 07 min 00 sec, Sir Martyn Poliakoff says:
The final, and I have to admit perhaps slightly boring application ...