Molecular dynamics simulation of effect of non-condensable gases on heat transfer of water molecule flow in nanochannels

Abstract

As the realm of electronics progresses toward higher performance and miniaturization, the study of flow heat transfer within nanochannels has garnered increased scrutiny. To elucidate this phenomenon, molecular dynamics simulations were employed to emulate the behavior of fluids within nanochannels at temperatures of 300K, 325K, and 350K. Water served as the flow medium, with argon substituted for any non-condensable gases present. Within the flow process, argon atoms aggregate to form clusters characterized by high potential energy. As the temperature incrementally rises, there is a concomitant increase in the fluid's potential energy, which leads to the gradual diminution or complete dissipation of these clusters. A minor presence of gas atoms can facilitate fluid movement; however, an excess of argon promotes the formation of larger gaseous clusters within the central region of the channel, thereby impeding fluid flow. Concurrently, the application of heat to the fluid appreciably diminishes the coefficient of flow resistance. The temperature of the fluid in the near-wall region exceeds that of the central area. Within the clusters, the atoms exhibit heightened activity, leading to an increase in the average molecular kinetic energy and a concomitant rise in temperature. The hydrogen-bonding structure inherent to water augments heat transfer within the nanochannels. Argon atoms exert an influence on the quantity of hydrogen bonds present, and elevated temperatures disrupt the hydrogen-bonding network established by water molecules, culminating in a diminution of the Nusselt number. This investigation offers insights into the heat transfer dynamics of water molecular flow within microchannels under the perturbation of non-condensable gases, thereby furnishing theoretical guidance for the enhancement of heat transfer within electronic devices.