Mass-flow-rate-controlled fluid flow in nanochannels by particle insertion and deletion

Abstract

A nonequilibrium molecular dynamics method to induce fluid flow in nanochannels, the insertion-deletion method (IDM), is introduced. IDM inserts and deletes particles within distinct regions in the domain, creating locally high and low pressures. The benefits of IDM are that it directly controls a physically meaningful quantity, the mass flow rate, allows for pressure and density gradients to develop in the direction of flow, and permits treatment of complex aperiodic geometries. Validation of IDM is performed, yielding good agreement with the analytical solution of Poiseuille flow in a planar channel. Comparison of IDM to existing methods indicates that it is best suited for gases, both because it intrinsically accounts for compressibility effects on the flow and because the computational cost of particle insertion is lowest for low-density fluids.

Hydrodynamic and thermal flow in nanochannel to study effects of roughness by estimation the atoms positions via MD method

“…At nanometer scales, when the dimension of structure is small, nanochannel and fluid surface interaction become very important. The fluid–nanochnnel interaction physics is able to be described via non-equilibrium molecular dynamics method (NEMD) (Allen and Tildesley, 1989; Cieplak et al , 1999; Travis and Gubbins, 2000; Xu and Zhou, 2004; Priezjev et al , 2005; Barclay and Lukes, 2016; Skrobas et al , 2019; Karniadakis et al , 2005; Sofos et al , 2009; Binder et al , 2004). Today, the existence of atomic incompleteness in industrial products is inevitable and these phenomena appear in nanochannels too.…”