Basic research on flow of nanofluids in cooling system of internal combustion engine

As a substitute of traditional cooling medium, a heat transfer fluid with higher thermal conductivity and better heat transfer performance(nanofluids) was applied to the cooling system of internal combustion engine and the fundamental research on flow characteristics of nanofluids was performed to provide the theoretical support to its application. The present work made a visualization study on nanofluids flow in a waved-wall tube to clarify flow mechanism of nanofluids and promote the application of nanofluids in cooling system of internal combustion engine. Study found that the viscosity of nanofluids decreased as increasing temperature and conformed almost exactly to base liquid at high temperature. In the wavedwall tube and under the same inlet velocity condition, the flow of nanofluids is more active than that of the base liquid. The number of vortex is increased, mass transfer characteristic is strengthened and turbulence effect is increased with the increase of particle concentration. In addition, it is found by molecular dynamics analysis that there exists strong turning effort of nanoparticles in nanofluids flow and micro turbulent flow effect is promoted, leading to further strengthened turbulent flow effect of nanofluids.