Heat transfer between 2 mediums

  • Thread starter Thread starter sgstudent
  • Start date Start date
  • Tags Tags
    Heat Heat transfer
AI Thread Summary
Heat transfer from heated metal to air occurs through conduction, followed by convection and radiation. The type of gas surrounding the metal affects the conduction process, with denser mediums like water facilitating faster heat transfer. In heat exchange systems, a better conducting metal will enhance heat removal from hot water more effectively than a poorer conductor. When cooling, a red-hot metal rod and a silver rod will cool at similar rates due to equal radiation effects, but their temperature distribution affects conduction. Ultimately, the specific heat of the surrounding medium plays a crucial role in the rate of heat absorption and dissipation.
sgstudent
Messages
726
Reaction score
3
Hi guys, I have a question regarding heat transfer. When I have a piece of heated metal which is left to cool down in air, it goes something like this right? Heat is transferred to air by conduction (metal to air) then from air heat is given off by convection currents. Also, radiation occurs. But I was wondering if the heat transfer from metal to air (conduction process) will change if another gas is used. I'm guessing it will have another effect because if water is used instead more heat will be transferred. So does it mean that the denser the covering medium, the faster the heat can escape? So for heat exchanges where hot water is pumped through a metal pipe, if 2 different metals are used will the better conductor metal take away more heat at the transferal part (water to metal). I don't really understand this though.

Also, if I have two pieces of metal rods which is heated in a fire and one becomes red hot and the other remains silver it means that the silver one is hotter at the other end (not in the fire) as the heat is able to transfer to the rest of the parts while the red hot one accumulates the heat at one place so the end will be not as hot as compared to the silver one. But if I were to take both of them out to cool in the same environment, then which one will cool faster? I'm guessing it should be the same as radiation will be the same as the silver one is hot throughout whole the red hot one is extremely hot at one part and cool at the other, so net radiation is equal. So it boils down to conduction through the 2 mediums, so I'm guessing it should be the same too?
Thanks for the help!
 
Science news on Phys.org
The rate at which heat is absorbed or given away depends on specific heat. Since water has a high specific heat, it takes in more heat to show a small change in temperature. Any gas can't compete with water.
The rod which is not silverish will radiate the heat quickly(black body radiation). (even though it may not be 'black', it is blacker than the silver rod!).
 

Thread 'Entropy and configurations of microstates'

I was watching a Khan Academy video on entropy called: Reconciling thermodynamic and state definitions of entropy. So in the video it says: Let's say I have a container. And in that container, I have gas particles and they're bouncing around like gas particles tend to do, creating some pressure on the container of a certain volume. And let's say I have n particles. Now, each of these particles could be in x different states. Now, if each of them can be in x different states, how many total...
View full post »
Thread 'Why work is PdV and not (P+dP)dV in an isothermal process?'

Thread 'Why work is PdV and not (P+dP)dV in an isothermal process?'

Let's say we have a cylinder of volume V1 with a frictionless movable piston and some gas trapped inside with pressure P1 and temperature T1. On top of the piston lay some small pebbles that add weight and essentially create the pressure P1. Also the system is inside a reservoir of water that keeps its temperature constant at T1. The system is in equilibrium at V1, P1, T1. Now let's say i put another very small pebble on top of the piston (0,00001kg) and after some seconds the system...
View full post »

Similar threads

A Calculating the heat loss of an open water tank (aquarium)
Replies
2
Views
3K
Can heat transfer break an equilibrium?
Replies
3
Views
1K
A Practical use of an overall heat transfer coefficient?
Replies
14
Views
2K
Rate of conduction heat transfer with different hot-side and cold-side areas
Replies
8
Views
2K
How does solar radiation contribute to heat transfer through windows?
Replies
2
Views
2K
Help understanding "Heat capacity"
Replies
28
Views
3K
Two or three types of heat transfer?
Replies
10
Views
8K
I What is the Role of Convective Heat Transfer in Cavitation of Cryogenic Fluids?
Replies
7
Views
2K
B Are wind farms stealing the cooling capacity of the wind?
Replies
4
Views
3K
Does Copper Conduct Heat Better than cPVC?
Replies
2
Views
1K

Hot Threads

Recent Insights

Back
Top