Help with Evaporation Rates for school project

[JoshHarpst]

Hello everyone, my name is Josh Harpst (if you couldn't figure that out) and am in my 6th semester at slippery rock university. I am a Mathematic's major and just got an invitation into KME (Kappa Mu Epsilon) the national honoray Mathematics fraternity. To get inducted you must do a research project and i thought, hmm, with all the time i don't have what can i do? So i decided that i wanted to have it deal with something i am passionate about and that just so happens to be Saltwater Aquariums. Well the project has to deal with math so i decided i wanted to do research on Evaporation rates due to temperature in the saltwater aquarium. This will involve differential equations and such so it's mathematical. So what i need your help with is some information. Any sites or anything that deal with evaporation. The mission of this research is to model an equation that can help predict the mean rate of evap due to temperatue so that way aquarists can calculate the amount of water they need to drip into the system while the water is evaporating to keep salinity stable. Any help or motivation would be greatly appreciated. I have just started this reseach today and the project needs to be completed by April 10 to be inducted. So thanks in advance and hopefully i'll get this thing running. Thanks everyone.


~Josh Harpst

[tanker]

There are lots of factors involved. Air temp, water surface movement (amount if any), humidity of air (water content of air), water temp, surface area, ect. No simple equation. IMO.

[JoshHarpst]

i totally agree, that is why i'm going to try to find the averge evap. There are tons and tons of variables and at this time i am only going to deal with the variables water temp/air temp and open surface area. Thanks a lot for the input,

~Josh

[mike89t]

Originally posted by tanker
There are lots of factors involved. Air temp, water surface movement (amount if any), humidity of air (water content of air), water temp, surface area, ect. No simple equation. IMO.

I agree. There are way to many variables that would complicate the equation.

If I were to try and do this I would Fill several tanks of the same size with the same amount of water. Then I would heat the water to different temps in each of the tanks. After a certain amount of time you could measure the amount of water evaporated over time.

The best bet would be to do all the tanks at the same time in the same room.

[JoshHarpst]

good idea, thanks for the help.

~Josh

[BurntOutReefer]

You can find the answer to this in any introductory thermodynamic text book.
Essentially, you will be looking at the heat of vaporization, the amount of heat it takes for a specified amount of liquid to vaporize.
or click here;
http://www.newton.dep.anl.gov/askasc...1/gen01002.htm

[liao]

Reminds of biology lab where we once did an experiment measuring the perspiration(transpiration) of plants.

[Richard Walston]

JoshHarpst

Hope this may help.

Evaporation Station Observations

[Shoestring Reefer]

I aslo agree you should do a controlled experiment; but you can determine the humidity in the room (wet bulb vs dry bulb), and vary the humidity (humidifier, dehumidifier) to get more interesting results.

Obviously, this has all been done. ASHRAE may have the data. But finding it out for yourself seems more interesting.