We are looking for convective heat transfer coefficient values to compare with our field experimental results
Poster Fine scale monitoring of ice ablation following convective h...
I think this problem could be modeled as the boundary flow past an isothermal plane surface. For laminar flow, the average Nu=0.68 Re^(1/2) Pr^(1/3). For turbulent, the average Nu=0.5 f * Re * Pr^(1/3) where the skin friction f = 0.079 / Re^0.25 or 0.0014 + 0.125/Re^0.32.
More correlation of Nu can be found in heat transfer books.
Shiuh-Hwa, thanks for your answer. Do you have any experimental values for this coefficient?
I don't have on my hand. But, I believe the heat transfer textbook should have. E.g., Fundamentals of Heat and Mass Transfer by Frank P. Incropera, David P. DeWitt.
I'm checking with Incropera textbook and found that the sec. 7.2 might be the one you want to look at.
Thanks much Shiuh. I have that text book. However, these are theoretical values. We recently ran experiment in the field and in the lab to try to derive a convective heat transfer coefficient to ue it later in equations for a model. But we came up with incredibly high values which are unlikely to be good. I wanted to see if others got the same problem in experiments.
Daniel, perhaps you have a mixed convection. Sec 9.9 discusses how to combine the free convection and force convection as the 1st approximation. You can also use CFD as a tool to find the convective heat transfer coefficient.
Hi Shiuh, again thanks much for your help in this matter. I will look into this. My feeling is that there isn't free convection as it is surface run-off water flowing over and into permafrost ground ice. There's no standing water that would allow for free convection. I received a paper from another researcher (experimental values) that shows, without explanation though, that ice surface inclination does change the ablation rate of ice. I haven't had time to read it n details but I hope it will help us to explain on very high melting rates. I will ask my PhD student who works on that topic to dig a bit more about that. I apreciate your help.
I see. I missunderstood your problem. I mistook that the permafrost ground is exposed to the air. In that case, there is no free convection.
There is a phase change for ice melting as well as the force convection in the flowing water. If the ice surface is rough, and/or has some holes, it will be more complex. There is an review paper you might be interested in:
"Melting and Freezing" L.S. Yao ,J. Prusa "Advances in Heat Transfer, Volume 19, 1989, Pages 1–95
Hello there Shiuh, I will read through 'Melting and Freezing' soon - I think we may obtain some answers there regarding our specific context.
further, we have forced convection in our case as water is flowing over the ice. Well I am digging in thank you for referring these papers, I'll update eventually when I'll have something new
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