Nano- and micro-fluids yielded a great interest in the heat transfer fluid field in the last ten years. The advantages in using such heat transfer fluids are related to the material, dimension and shape of nanoparticles or microparticles dispersed within base fluid (water, oil, etc.). In this work a new experimental setup has been designed, built and tested in order to investigate the physical phenomena involved in thermal conductivity enhancement of these fluids. In particular, a low temperature test rig has been conceived for carrying out experimental campaigns in ranges of temperature that allow to reduce or eliminate some physical phenomena that could affect the thermal conductivity measurements (Brownian vibrations, phonon scattering, etc.). The use of Peltier cells, hot disk technique and thermal bath allowed to obtain stable and reliable measurements, with nanofluid and microfluid based on diathermic oil for high and low temperature applications. All heat transfer fluids showed enhancement in thermal conductivity, but the first results obtained with diathermic oil and alumina nano and micro particles showed different behaviors, highlighting the effects due to the dimension of particles and excluding other physical phenomena.
Experimental setup for low temperature thermal conductivity analysis of micro and nano suspensions
Colangelo G.
;Milanese M.;Iacobazzi F.;De Risi A.
2019-01-01
Abstract
Nano- and micro-fluids yielded a great interest in the heat transfer fluid field in the last ten years. The advantages in using such heat transfer fluids are related to the material, dimension and shape of nanoparticles or microparticles dispersed within base fluid (water, oil, etc.). In this work a new experimental setup has been designed, built and tested in order to investigate the physical phenomena involved in thermal conductivity enhancement of these fluids. In particular, a low temperature test rig has been conceived for carrying out experimental campaigns in ranges of temperature that allow to reduce or eliminate some physical phenomena that could affect the thermal conductivity measurements (Brownian vibrations, phonon scattering, etc.). The use of Peltier cells, hot disk technique and thermal bath allowed to obtain stable and reliable measurements, with nanofluid and microfluid based on diathermic oil for high and low temperature applications. All heat transfer fluids showed enhancement in thermal conductivity, but the first results obtained with diathermic oil and alumina nano and micro particles showed different behaviors, highlighting the effects due to the dimension of particles and excluding other physical phenomena.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
