Hello,
When I choose convective flux as a BC I find that the transfer coefficient is in (/m) unit. Shouldn’t it be in (W/m2K)? Can anyone explain to me this and tell what conversion should I use?
Thanks a lot = )
Hello, we need you to be more specific with your problem, for example, what type of BC do you want? When you say “transfer coefficient” do you mean “heat transfer coefficient” or “mass transfer coefficient”? is it a BC or IS?
We look forward to more information to help you
Hi -
I think Mariam is asking about the inputs indicated in the screenshot below, as this the only place in the MFiX interface where the terms “Convective flux” and “Transfer coefficient” appear
The control labeled “Transfer coefficient” controls the MFiX variable (keyword) bc_hw_t_s - you can see this by hovering over the control. The help text (visible in the popup or the Search Keyword popup) says:
the C appearing on the right hand side is bc_c_t_s:
This is labeled “Constant flux” in the interface and is forced to 0.
I think it’s correct that C has units of K/m since it’s a spatial derivative of temperature.
Now Hw has to multiply by a temperature (difference of temperatures) and result in a quantity with dimensions K/m. So [Hw] * K = K/m, implying that Hw has dimensions of 1/m.
Hope this helps,
– Charles
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