Experimental Investigation into the Forced Convective Heat Transfer of Aqueous Fe 3 O 4 Nanofluids under Transition Region

The forced convective heat transfer (FCHT) properties of nanofluids, made of Fe 3 O 4 nanomaterials and deionized water, are firstly measured by a self-made forced convective heat transfer apparatus. The nanofluid flows through a horizontal copper tube in the transition region with Reynolds numbers in the range of 2500–5000. Some parameters including Reynolds number, axial distance, and mass concentration are also investigated. The preliminary results are firstly presented that the heat transfer coefficients of Fe 3 O 4 nanofluids systematically decrease with increasing concentration of nanoparticles under transition region which contradicts the initial expectation.