A direct numerical simulation method for complex modulus of particle dispersions

Area of Science:

• Physics
• Materials Science
• Chemical Engineering

Background:

• Direct numerical simulation methods are crucial for understanding complex fluid dynamics.
• The smoothed profile method (SPM) is a technique used to simulate particle dispersions.
• Calculating the complex modulus is essential for characterizing the viscoelastic properties of materials.

Purpose of the Study:

• To extend the smoothed profile method (SPM) by incorporating a temporally oscillatory external force.
• To validate the enhanced SPM by calculating the storage (G') and loss (G") moduli of particle dispersions.
• To compare simulation results with experimental data for colloidal dispersions.

Main Methods:

• Extension of the smoothed profile method (SPM) with a temporally oscillatory external force.
• Direct numerical simulation of identical spherical particles in a Newtonian fluid.
• Evaluation of storage and loss moduli at various frequencies and volume fractions (Φ = 0, 0.41, 0.46, 0.51).

Main Results:

• The extended SPM successfully calculated the storage and loss moduli for particle dispersions.
• Simulation results showed good agreement with experimental data for colloidal dispersions.
• The method's validity was confirmed across different volume fractions and shear flow frequencies.

Conclusions:

• The temporally oscillatory external force extension of SPM is a valid and effective method for simulating particle dispersions.
• This enhanced method provides accurate predictions of viscoelastic properties, aiding in material characterization.
• The findings support the use of advanced simulation techniques for studying complex fluid systems.