Thermal conductivity and heat transfer of ceramic nanofluids

This study is motivated by the controversies surrounding nanofluids. Employing a rather simple but well defined test rig it is shown that heat transfer can be enhanced by nanofluids in the thermal entrance region of laminar pipe flow. The thermophysical properties necessary to interpret the results of these experiments are measured very carefully. It is found that the thermal conductivity of five different ceramic nanofluids – measured with a sophisticated ring gap apparatus - do not show any anomalous behavior. However, the dynamic viscosity is significantly increased compared with the basefluid.

► Thermal conductivity of ceramic nanofluids does not show any anomalous behavior. ► The dynamic viscosity of the nanofluids considered is significantly increased. ► Heat transfer is enhanced in the thermal entrance region of laminar pipe flow.