[Arakis]

Hello everyone,

I am trying to use ANSYS CFX to simulate the heat transfer on a hot day from the roof of a house into the living areas. I ma having some difficulties setting up the simulation. In essence this is what I am trying to do:

There is the sun generating a heat flux onto the metal roof sheets.
The roof sheets get hot, which causes the air under the roof to get hot. This hot air then causes heat transfer through the ceiling into the living area. I am interested in the flow patterns and temperature distribution of the hot air that flows in the roof cavity, and would like to study the difference in the temperature in the roof cavity if there were openings in the roof compared to a sealed roof.

Any guidance or recommendations would help alot. Thanks

[Abou ali]

Hi,
I think that Tutorial 17 in CFX help (Air Conditioning Simulation) treats a similar problem as yours, you can use it as a guideline in your simulation.

In general, you have to:
1- activate the Buoyancy Option in the Domain Models definition under General Options;
2- activate the Thermal Radiation Model Option in the Domain Models definition under Fluid Models;
3- use a Radiation sources in appropriate walls.

[rogbrito]

Tutorial 17 in CFX help (Air Conditioning Simulation):


http://www.4shared.com/file/72198900...ningSimul.html


http://www.4shared.com/file/72199871...ningSimul.html

Originally Posted by Arakis

Hello everyone,

I am trying to use ANSYS CFX to simulate the heat transfer on a hot day from the roof of a house into the living areas. I ma having some difficulties setting up the simulation. In essence this is what I am trying to do:

There is the sun generating a heat flux onto the metal roof sheets.
The roof sheets get hot, which causes the air under the roof to get hot. This hot air then causes heat transfer through the ceiling into the living area. I am interested in the flow patterns and temperature distribution of the hot air that flows in the roof cavity, and would like to study the difference in the temperature in the roof cavity if there were openings in the roof compared to a sealed roof.

Any guidance or recommendations would help alot. Thanks

[kingjewel1]

Dynamic Thermal Modelling is the study of the influence of the sun on indoor thermal comfort during the day. I don't know if CFX has a radiation model which allows for a moving heat source, unless you can model your heat source algebraically.