Heat transfer enhanced in water containing TiO ₂ nanospheres

In the present work, nanofluids containing spherical TiO ₂ nanoparticles were mixed in water, to have various concentrations with the average particle diameter of 81.3 nm. Scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction techniques were used to characterize the TiO ₂ nanoparticles. Photothermal techniques, thermal lens spectrometry (TLS) and photopyroelectric (PPE) were used to measure the thermal diffusivity and thermal effusivity of the nanofluids respectively. The experimental results show that the thermal diffusivity (D) increased with the increase in TiO ₂ nanoparticle concentration. It was also possible to see that thermal effusivity (e) had a similar behavior as the thermal diffusivity, where both the values increased with the concentration rate and finally a comparison with literature values show good agreement with the thermal parameters of water.