Nanofluidics in hydrophilic nanopores is a common issue in many natural and industrial processes. Among all

the mass transport of nanofluidics is most concerned. Besides that

the heat transfer of a fluid flow in nano or micro channels is always considered with adding nanoparticles into the flow

so as to enhance the heat transfer by convection between the fluid and the surface. However

for some applications with around 1 nm channels such as nano filtration or erosion of rocks

there should be no nanoparticles included. Hence

it is necessary to figure out the heat transfer mechanismin the single phase nanofluidics.

Via

non-equilibrium molecular dynamics simulations

we revealed the heat transfer inside nanofluidics and the one between fluid and walls by setting simulation into extremely harsh condition. It was found that the heat was conducted by molecular motion without temperature gradient in the area of low viscous heat

while it was transferred to the walls by increasing the temperature of fluids. If the condition back to normal

it was found that the vi

scous heat of nanofluidics could be easily removed by the fluid-wall temperature drop of less than 1 K.