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

Area of Science:

• Computational physics
• Fluid dynamics
• Nanotechnology

Background:

• Simulating fluid flow in nanochannels is crucial for understanding nanoscale phenomena.
• Existing methods may not accurately capture compressibility effects or handle complex geometries.

Purpose of the Study:

• Introduce a novel nonequilibrium molecular dynamics method, the insertion-deletion method (IDM), for inducing fluid flow in nanochannels.
• Validate IDM's accuracy and compare its performance to existing simulation techniques.

Main Methods:

• The insertion-deletion method (IDM) involves inserting and deleting particles in specific regions to create pressure gradients.
• IDM directly controls the mass flow rate, allowing pressure and density gradients to develop.
• The method is applied to simulate Poiseuille flow in a planar channel.

Main Results:

• IDM shows good agreement with the analytical solution for Poiseuille flow.
• The method intrinsically accounts for compressibility effects, making it suitable for gases.
• Computational cost is lowest for low-density fluids, indicating efficiency for gas simulations.

Conclusions:

• The insertion-deletion method (IDM) is a validated and effective approach for simulating fluid flow in nanochannels.
• IDM offers advantages in directly controlling mass flow rate and handling complex geometries.
• This method is particularly well-suited for simulating gas flows due to its inherent treatment of compressibility.