Heat Transfer in a Square Duct
Heat Transfer in a Square Duct
(OP)
I am trying to figure out how to model heat transfer in a square duct. Specifically, this is a honeycomb of channels within a duct of flowing hot air. The flow through the channels is laminar, and the entire mass of the honeycomb is heating up from the hot air flow.
Any suggestions on where to start? Initially I was thinking of just using the heat capacity of the material. However, I think the answer really depends on conductive and convective heat transfer. Since the honeycomb is heating up, it's transient heat transfer. However, with an undergraduate understanding of heat transfer mechanics, I'm having trouble coming up with the equations of non-steady state heat transfer.
Thank you in advance for the help!
Any suggestions on where to start? Initially I was thinking of just using the heat capacity of the material. However, I think the answer really depends on conductive and convective heat transfer. Since the honeycomb is heating up, it's transient heat transfer. However, with an undergraduate understanding of heat transfer mechanics, I'm having trouble coming up with the equations of non-steady state heat transfer.
Thank you in advance for the help!





RE: Heat Transfer in a Square Duct
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RE: Heat Transfer in a Square Duct
As the turbine is starting up, the exhaust temperature is changing. As this heated exhaust passes through the honeycomb, the honeycomb heats up. I would like to find the temperature of the honeycomb at different points in time.
I think that I can assume the Tin and Tout of the honeycomb structure are roughly equal. Additionally, the walls of the honeycomb structure are very thin, so I believe I can assume the Tsurface is equal to the Tbulk
Thanks!
RE: Heat Transfer in a Square Duct
RE: Heat Transfer in a Square Duct
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RE: Heat Transfer in a Square Duct
So to find the temperature change of the overall mass in that case, I'm going to use the lumped method to find the amount of heat transfer, and then use the heat capacity to calculate the temperature change of the honeycomb?
RE: Heat Transfer in a Square Duct
Then, look at the approximate answer you got. Decide if that is good enough (Hint: It probably won't be) then use the approx result to start your second and third iterations.
It will never be "exact" and at some point in time, the effort of the extra calculations (and the approximations you are making in each calculation) will not increase accuracy of the result. First, do the start and end points of the time interval.
RE: Heat Transfer in a Square Duct
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