Thermodynamics: Modelling the internal environment of a tent

[Jakob81]

Hi,

I am trying to model the temperature profile of the inside of a tent, with a view to introducing a fan which can suck outside air, to inside the tent, to cool it down on a hot sunny summer morning.

I thought I would start by just trying to model the interior of a tent in these conditions without the fan.
I'm assuming 2 people inside giving of a total of about 160W of heat. I would like to assime solar gain from the sun providing approx 850W/m^2 of heat to the side of the tent. The outside air temp will be about 10 Deg C, I also have some experimental data on the rate of heat loss from my 'typical' tent.

What area of thermodynamics should I look into to start my model? It has been suggested to look at 'Adiabatic Mixing of Airstreams' but it seem to me this is not an adiabatic process as heat is being lost from the tent all the time.

Does anyone have any suggestions to get me going?

Thanks

 

[cronxeh]

Also look into the green house gases.. once of the 2 individuals decides to release x amount of gas, there will be local warming followed by reduced oxygen content

 

[Graeme Robinson]

for your question!

To model the internal environment of a tent, you will need to consider several principles of thermodynamics. The first is the conservation of energy, which states that energy cannot be created or destroyed, it can only be transferred from one form to another. In this case, the energy inputs to the tent are the heat generated by the two people inside and the solar radiation from the sun. The energy outputs are the heat lost through the tent material and any air exchange with the outside environment.

Secondly, you will need to consider the laws of thermodynamics, particularly the first and second laws. The first law states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system. In this case, the internal energy of the tent will change due to the heat inputs and outputs, as well as any work done by the fan if it is introduced.

The second law of thermodynamics states that in any thermodynamic process, the total entropy of a closed system will either remain constant or increase. This means that the overall disorder or randomness in the system will either stay the same or increase over time. In the case of the tent, this could manifest in the distribution of heat within the tent and the air flow patterns.

As for the specific area of thermodynamics to look into, it would be helpful to understand the principles of heat transfer, such as conduction, convection, and radiation. These will help you determine the rate of heat transfer through the tent material and the air inside the tent. You may also want to consider the properties of the materials used in the tent, such as their thermal conductivity and specific heat, to accurately model the temperature profile.

In terms of the fan, you are correct that this would not be an adiabatic process as heat is being lost from the tent. Instead, you may want to look into the principles of fluid mechanics and how air flow can affect the temperature and air distribution within the tent.

Overall, it will be important to carefully consider all the inputs and outputs of energy in your model and how they interact with each other. With some research and experimentation, you should be able to create a comprehensive model of the internal environment of a tent. Good luck!