Thanks Mr.Singh
I don't want to measure the evaporation rate by weight of droplet, because i don't have proper equipment .I want to know how can i calculate the evaporation rate of the sessile droplet with physical properties of the droplet ( such as height - contact angle - Base )
In addition , i want to measure the evaporation rate in just pin phase( Mode )
Hamid, The paper you want to look at is:
G.J. Dunna, S.K. Wilson∗, B.R. Duffy
S. David, K. Sefiane, "A mathematical model for the evaporation of a thin sessile liquid droplet:Comparison between experiment and theory", Colloids and Surfaces A: Physicochem. Eng. Aspects 323 (2008) 50–55
You will need to know/control the relative humidity of the environment to predict the evaporation rate.
If you are doing measurements, one easy thing to do is just record the time for a droplet to dry completely. You can then calculate droplet volume from base and height and get an average drying rate by dividing the two.
If you want to be more sophisticated, you can find expressions for the drop lifetime (e.g. from Picknett and Bexon, J Coll Int Sci, 61, 2, 1977) in terms of other parameters you should be able to measure.
Thanks all
Mr. David Fairhurst my purpose is to measure the evaporation rate by experimental method.
I can calculate the base - height - contact angle and drying time of sessile droplet.
would you please explain the second sentence that you wrote :
" You can then calculate droplet volume from base and height and get an average
drying rate by dividing the two "
what do you mean by Dividing two ?
Evaporation depends on the temperature as well as the humidity. A rough estimate can be made as explained by Dr. David. You can calculate the volume of the drop by measuring the base diameter and height of the sessile drop. Also, you can estimate the time required to evoporate the liquid completely. By taking the ratio between these two values, you can get an avarage evaporation rate.
Hi,
if the droplet is on non condentive substrate the Hu & Larson is adequate and if you want to tak einto acount thermal coupling you can find intersting and universal controling parameter see
http://dx.doi.org/10.1017/S0022112010005446 (About DOI),
- Badges
- Science topic
- Similar topics
- Engineering
- Thermal Engineering
- Thermofluid
- Fluid Mechanics
- Fluid Dynamics