Dear Ali, review these article, Article Experimental study on thermal conductivity of water-based Fe...

Article Experimental investigation on the convective heat transfer o...

you can use this equation for Nusselt number correlation for Fe3O4 nanofluid

Nu=0.0059·(1+7.628·φ^0.6886·Pe^0.001)·Re^0.9238·Pr^0.4

from

Xuan, Y., and Li, Q. (2003) Investigation on Convective Heat Transfer and Flow Features of Nanofluids. J. Heat Transfer, 125 (1), 151.

Thank you Eric.

I need to calculate the effect of the magnetic field on the heat transfer coefficient of ferrofluid. Do you know any correlation about it?

Dear Ali, I think these two articles will be great assistance for you. please look at them. regards

Thank you Mohammed

The second one was interesting.

Dear Ali, review these article, Article Experimental study on thermal conductivity of water-based Fe...

Article Experimental investigation on the convective heat transfer o...

Thanks Ali

Drs Mohammed and Ali, High level papers .. I commend to use them too.