Questions tagged [convection]

The tag has no usage guidance.

Filter by
Sorted by
Tagged with
0
votes
1answer
30 views

Why do we consider the normal component of velocity in a flux and not the original direction of velocity?

Below is the equation of convective flux of an arbitrary property that is carried by particles. When particles move they carry their property along with them. Given a fixed surface in space, in order ...
0
votes
1answer
77 views

How to calculate heat loss across a process pipe with perpendicular air flow

My thermodynamics knowledge is extremely rusty, so I would appreciate some guidance on how to solve this problem. As illustrated here, I have a process pipe (steel) with a gas flowing through it (blue)...
0
votes
1answer
18 views

Empirical correlation for low reynolds convective heat transfer coefficient

I am looking for a heat transfer coefficient for a shape (rectangular cross section preferred, could estimate with flow over flat plates) in 2 m/s cross flow. I have found a few empirical correlations ...
-1
votes
1answer
41 views

As a rugged and waterproof device, how does gopro dissipate heat?

I am new to designing rugged + waterproof products. I am curious about how to dissipate heat when the electronics are running and the ambient environment is even hotter. It seems like the mode of heat ...
1
vote
0answers
9 views

Heat Conduction/Convection Along discontinuous tube

I have a question regarding heat conduction/convection. I have a metallic tube over which a rope heater is wound, supplying power. A glass tube and a 2nd metallic tube lies at the exit of the first ...
1
vote
2answers
71 views

How to calculate heat and mass transfer rates from an enclosed box?

I'd like to know if it's possible to calculate the heat and mass transfer rates from a small volume to the environment. Let's assume there is a box with a small opening at the top. The air inside the ...
-1
votes
1answer
38 views

Heat transfer for a copper rod

For a copper rod heated by a heat gun, why might the temperature of the rod continue to increase for a short time after the heat gun has been removed as the heat source? With reference to transient ...
1
vote
1answer
22 views

How to consider the dimension of a cylinder when computing its radiative budget?

I am trying to derive a heat budget model to estimate the temprature of very small a stationary vertical cylinder (1mm) under environmental conditions. Imagine a wooden stick. Simply put, I have R = ...
0
votes
0answers
33 views

How to calculate heat transfer between two solids in a medium?

If I have a cuboid block of metal and there is a cylindrical source of heat input (A) and I want to determine the heat energy at B (also cylindrical) how would I do this? I understand considerations ...
0
votes
1answer
84 views

Wire heating and heat transfer in a cylindrical pattern

I have a series of copper coils with ¼” cooling plates between each coil. The cooling plates will be manufactured from aluminum and cooled using copper tubing. There are seven in series, and a plate ...
1
vote
1answer
151 views

Heat Transfer in Different Wire Configurations

I am trying to create a program which estimates the final temperature of a magnet made of copper wire. I have different configurations in mind, but I will start off with a straight square wire with a ...
1
vote
0answers
112 views

Minimum distance between long curtains and radiator for good air flow?

It's a known fact that you cannot place a curtain near a radiator because it will trap hot air behind the curtain and also block cold air from going through the radiator from bellow. But obviously ...
3
votes
1answer
657 views

What is the difference between the wave equation and the advection equation?

I am trying to understand what is the difference between the wave equation ad the advection equation? Bot the equation seems to move a quantity. While in literature it is said that the advection ...
1
vote
0answers
86 views

Ventilation requirements of a closed housing of a video wall

Our company builds rather large video walls that are driven by computers next to them. In one of our current project the size of the installation is 21 55" displays side by side in portrait mode and 4 ...
0
votes
1answer
39 views

convection query

I am attempting some convection analysis for research I am doing. I was wondering someone could kindly confirm whether I am on the right track. The calculation is based up air being passed over a flat ...
1
vote
1answer
75 views

Convection Heat Transfer

I am working on a problem at the moment and would appreciate some of your expertise regarding this issue. If you see the image below, I am trying to calculate heat transfer from a fluid entering a ...
0
votes
1answer
239 views

Most effective heat transfer in a vertical pipe with small top/bottom temperature difference?

What would be most effective way to transfer heat in the following situation? Specific conditions: A vertical cylinder or pipe, 30-100cm long, 5-10 cm in diameter, heavily thermally insulated except ...
1
vote
0answers
273 views

Calculating heat transfer in a cooling loop

Imagine a closed pipe like below, filled with a liquid. The pipe is copper. Then imagine a small point heat source of X watts applied to the outside of the pipe in the position shown. Heat warms the ...
1
vote
1answer
157 views

Characteristic dimension for combining free and forced convection?

I have a situation that I have a combination of free and forced convection over a cylinder. Remembering back from heat transfer, to combine these I use the formula $$Nu_{\mathrm{comb}}^n = Nu_{\...
2
votes
1answer
108 views

Can I neglect kinetic energy when modeling convective heat transfer for viscous, low mach airflow? Why or why not?

I'm looking at convective heat transfer for air flow over a solid at Ma=0.2. At this speed, it is plausible to model the flow as incompressible because of small density variations in the air. ...
2
votes
1answer
468 views

Convective heat transfer coefficient in finite difference method boundary conditions

Suppose there is a cubic material with an internal heat source ($\Delta q / \Delta t =$ Constant), and is immersed in a sufficiently large amount of water. Now I would like to use finite difference ...
4
votes
1answer
217 views

How to determine if mass transfer convection is natural or forced?

I know that forced convection requires some external bulk flow, but is there an equation to determine which form of Convection is dominant? I looked around and found the Richardson number $\mathrm{Ri}=...
2
votes
1answer
347 views

Heat transfer characteristics in narrow rectangular channel

Please take a look at following figure: System considered is a narrow rectangular channel of 2.5 mm depth (W x L is 60 mm x 150 mm). Since channel has low depth, it can be considered as mini-channel. ...
4
votes
1answer
1k views

Heat Transfer coefficient calculation for hot air flow inside rectangular duct

I am working on modeling of air-heater component. A simplified representation of system is as follows: Cold air flow enters steel duct at one end. Inside duct is Calrod heating element shaped as ...