Nanoparticle Injection (Cone-Type) , ANSYS Fluent CFD Simulation

Introduction

This report details a nanoparticle simulation conducted using ANSYS Fluent. The primary focus is on the behavior of nanoparticles in a fluid environment, with particular attention to particle injection properties and simulation parameters.

The simulation geometry consists of a rectangular cuboid created in SpaceClaim. Meshing was performed in ANSYS Meshing, resulting in a grid of 151,294 triangular cells, providing a balance between accuracy and computational efficiency.

Simulation Setup in ANSYS Fluent:

The simulation was configured in ANSYS Fluent with the following key settings:

Discrete Phase Model (DPM) activated

Flow and turbulence equations deactivated

Gravity enabled: 9.81 m/s² in the negative y-direction

Standard initialization used

Initial velocity: 1 m/s in the y-direction, 0 m/s in other directions

Nanoparticle Injection Properties The injection properties were set as follows:

Nanoparticle Size Configuration To accurately simulate nanoparticles, an additional step was necessary:

The default minimum particle diameter in Fluent’s GUI is 1e-8 m.

To model true nanoparticles, the following command was executed in the Fluent console: /define/models/dpm/options> set-minimum-particle-diameter

This command allowed setting the minimum particle diameter to 1e-10 m, enabling the simulation of particles at the nanoscale.

Simulation Time and Type The simulation was set up as a transient analysis, allowing for the observation of nanoparticle behavior over time.

Simulation Results

Figure 3 shows the particle diameter distribution at different time steps (1.5e-02 s, 3.0e-02 s, and 4.5e-02 s). This series of images illustrates the evolution of particle dispersion over time. The particles appear to spread out from the injection point, forming a cone-shaped distribution that expands as time progresses.

At 1.5e-02 s, the particles are concentrated near the injection point. By 3.0e-02 s, they have dispersed further, and at 4.5e-02 s, the particles have spread even more, occupying a larger volume of the simulation domain.

The color variation in the particles represents different particle diameters, as specified by the Rosin-Rammler distribution used in the injection setup.

This simulation provides insights into the behavior of anthracite particles injected into a confined space, showing how they disperse over time under the influence of gravity and initial injection parameters.

Conclusion:

This setup allows for a detailed simulation of nanoparticle injection and dispersion in a fluid environment. The use of the console command to set a smaller minimum particle diameter enables the study of true nanoparticle behavior, which is crucial for applications in nanotechnology and fluid dynamics at the nanoscale.