is it appropriate to use LMTD for a car radiator?

[knight92]

I have an air cross flow radiator where the air flows perpendicular to the flow of water i.e. water goes left to right in the tubes and air passes through the fins from front to back. In this case would it be appropriate to use the LMTD method or should I use something else ?

 

[IRstuff]

LMTD is intended for scenarios where the two fluids are travelling along parallel paths be they in the same direction or opposite.

TTFN
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[knight92]

Well I found something that says there is a correction factor you get from a graph for a cross flow radiator...would this be right ?

 

[25362]

http://iosrjournals.org/iosr-jmce/papers/RDME-Volume2/RDME-11.pdf

 

[ione]

It is possible to use both methods. The LMTD method asks for a correction factor, which is available in graphical form. The effectiveness method (NTU) is anyway preferable for this kind of arrangement.

 

[FredRosse]

Either LMTD with correction factor (F), or the NTU method will predict the same results. I have always found the NTU-Effectiveness methods more suitable for predicting performance. In the case of an automotive type radiator, the temperature change of the liquid coolant is very small (on the order of a few percent, or even less than 1 percent of the bulk air to bulk liquid coolant temperature differential), and methods far more crude than established proper mathematical methods will usually work as well.