ナノ流体で満たされた多孔質体における粒子機械分散の数値解

抄録

Substantial heat transfer enhancement is possible using a passage filled with a nanofluid saturated metal foam, because of its high specific surface area, high thermal conductivity and comparatively low pressure drop. In addition to the Brownian diffusion and thermophoresis associated with nanofluids, one must fully understand both thermal dispersion and particle mechanical dispersion, so as to elucidate their combined effects on the heat transfer enhancement mechanism. Microscopic numerical calculations were conducted using a numerical model describing a structural unit of a passage filled with nanofluid saturated metal foam. The results were integrated over a local control volume, to evaluate the mechanical dispersion terms, purely from the theoretical basis. The present study reveals that the effect of the particle volume fraction on the thermal dispersion correlation is only minor, so that the correlations obtained for the base fluid can be used universally. On the other hand, the nanoparticle mass flux is found rather sensitive to the interstitial heat transfer rate from the metal to nanofluid, since it increases with the interstitial heat transfer rate.