[gaurav_1guru]

Dear friends,
As a part of my M.Tech project I am associated with calculating the temperature rise in busbars (copper plates) of switchgear.
The geometry consists of copper plates placed inside a closed container with air around it the flow of air is due to natural convection between the busbars also there is conduction through the plates due to a current of 2500 ampere, which results in heat generation. Also the effect of radiation can not be neglected. The analysis is time dependent.
Kindly consider the problem serious and respond as soon as possible.
As I am not an expert in Fluent I am not able to get the results.
Thanking you in advance...

[mvee]

Hi

put gravity on.
Natural convection in air and sf6 is governed by buoyancy which requires gravity to be on.

Thanks
mvee

[gaurav_1guru]

have u done analysis on this project if yes please provide more details and if possible send me details at gauravisguru@gmail.com

[sreenivas]

HI Guarav

For this kind of simulation you need to consider all the modes of heat transfer.For this you need to have the solid mesh surrounded by the fluid mesh( for simulating Natural convection and Radiation).First simulate the Conduction part and then you will get an idea about the wall temperature and use this as temperature boundary condition when you resolving buoyancy driven flows and Radiation heat transfer.Make sure that your gravity is switched on for this.By looking at the residuals ...there is no need to run for that many iterations...may be 2000 to 3000 iteration will be sufficient to come to conclusion

let me know if you need anything

Regards
srinivas

[gaurav_1guru]

I am still having problem with the switchgear project.
Please see if u can help.

I am doing 2D analysis
PROBLEM SETUP
general
1. solver is density based
2. first i am doing steady analysis, then will see transient.
3. putting gravity on at Y = -9.81 m/s2
models
1. energy on
materials
1. fluid is air (incompressible ideal gas)
2. solid is copper
cell zone condition
1. adding energy source term in solid (82413 W/m3)
boundary condition
1. zero heat flux for boundary (container)
2. bus bar edges walls are coupled in thermal tab

Also, I am attaching the mesh and case file, although some elements are highly skewed.

Also see that if i am doing correct calculation for heat generation
I have taken Q= I *I*R (i square r)

thus volumetric heat generation is Qgen = (I*I*R) / V