Electrophoresis Enhanced Heat Transfer Of Nanofluids

Nanofluids greatly improve the heat transfer performance of traditional heatexchange system, which has broad application prospects in enhancement of heat transfer.In order to obtain stable and well electrophoretic forced heat transfer performance ofnanofluids(ND-5/ethanol, ND-50/ethanol, ND-250/ethanol, SiO2/ethanol andAl2O3/ethanol), experiments studied the stability of different suspension after ultrasonicoscillation and the thermal conductivity of nanofluids was taken by transient hot wiremethod, also analysed different experimental conditions to the influence of thermalconductivity, such as the size of nanoparticles, concentration, different of nanoparticles.We invested the performance of electrophoresis enhanced heat transfer of nanofluids,under an applied DC electric field. We also observed suspension concentration, particlesize of nanoparticles, different nanoparticles to the influence of electrophoresis enhancedheat transfer of nanofluids.The experimental results show that the heat transfer performance of nanofluids hasgreatly improved by the transient hot wire method to measure the thermal conductivity ofnanofluids. Thermal conductivity of nanofluids increases with solid content increases, theparticle size decreases; the better stability of suspension, higher heat conductivity ofnanoparticles. ND-5/ethanol nanofluid showed the best heat transfer, the thermalconductivity of ND-5/ethanol increased2.9times for the base fluid at a concentration of0.5%.Charged nanoparticles in a suspension would migrate toward a conductive electrodewith the opposite electrical potential under an electric field, When the electrophoresisdirection is consistent with heat transfer, nanoparticles moved from high temperature tip tolow temperature and enhanced the heat transfer. The experimental results showed that thenanoparticles in the nanofluid were drived to move from high temperature tip to lowtemperature one under an applied DC electric field, enhanced the heat transfer from aboveto below and broken the limitation of the direction of heat transfer. The electrophoresisforced heat transfer of nanofluid enhance with the increased of electric field intensity, the increased of mass concentration of nanofluid, the minish of particles size. In our study wefound that ND-5/ethanol nanofluid electrophoresis forced heat transfer performance is bestwhen the field intensity of300V/cm and the mass concentration of0.4%, temperaturedifference changed of7℃was eliminated at a short time.