# Numerical Simulation of Particle Dynamics in a Spiral Jet Mill via Coupled CFD-DEM

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## Abstract

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## 1. Introduction

## 2. Numerical Methods

## 3. Results

#### 3.1. Fluid and Particle Dynamics

#### 3.2. Particle Collision Statistics

## 4. Conclusions

## Author Contributions

## Funding

## Acknowledgments

## Conflicts of Interest

## References

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**Figure 1.**The isometric view (

**a**) of the CAD geometry used for CFD-DEM simulations of the jet mill [28,29]. The red section in the top (

**b**) and front (

**c**) view of the geometry depicts the particle factory in which the initial particle bed is generated. The green section in the front view (

**c**) depicts the particle factory through which particles are dynamically fed once the initial particle bed is dispersed.

**Figure 4.**Evolution of fluid field in the jet mill along the mid plane for 100,000 particles with an operating pressure of 3 bar.

**Figure 6.**Probability distribution and box plot for particle velocity with increasing particle loading and two operating pressures.

**Figure 7.**Streamlines of first five particles fed to the mill while describing their motion in the mill for 0.15 s after the feeding. Case (

**a**) depicts the streamlines for three particle loadings at 3 bar operating pressure, and case (

**b**) depicts the streamlines at two operating conditions and particle loading of 100,000 particles.

**Figure 8.**The number of particle–particle (P–P) and particle–wall (P–W) collisions as a percentage of the total collisions for three loadings and two operating pressures. The total number of collisions as a normalized percent of the maximum collisions across all conditions. Collision data collected over 0.15 s after the start of particle feeding.

**Figure 9.**The total number of collisions per particle for the three loadings and two operating pressures over 0.15 s after the start of the feeding phase.

**Figure 10.**Collision velocity distribution for particle–particle (P–P) and particle–wall (P–W) collision for all cases. Collision data collected over 0.15 s after the start of particle feeding.

**Figure 11.**Scatter of the tangential component and normal component of the collision velocity for all cases studied. Collision data collected over 0.15 s after the start of particle feeding.

Particle Property | Value |
---|---|

Diameter | 200 m |

Density | 1525 $\mathrm{kg}/{\mathrm{m}}^{3}$ |

Young’s Modulus | 2.7 × 10${}^{8}$ Pa |

Poisson’s Ratio | 0.35 |

Coefficient of Restitution | 0.5 |

Coefficient of Static Friction | 0.5 |

Coefficient of Rolling Friction | 0.01 |

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**MDPI and ACS Style**

Bhonsale, S.; Scott, L.; Ghadiri, M.; Van Impe, J.
Numerical Simulation of Particle Dynamics in a Spiral Jet Mill via Coupled CFD-DEM. *Pharmaceutics* **2021**, *13*, 937.
https://doi.org/10.3390/pharmaceutics13070937

**AMA Style**

Bhonsale S, Scott L, Ghadiri M, Van Impe J.
Numerical Simulation of Particle Dynamics in a Spiral Jet Mill via Coupled CFD-DEM. *Pharmaceutics*. 2021; 13(7):937.
https://doi.org/10.3390/pharmaceutics13070937

**Chicago/Turabian Style**

Bhonsale, Satyajeet, Lewis Scott, Mojtaba Ghadiri, and Jan Van Impe.
2021. "Numerical Simulation of Particle Dynamics in a Spiral Jet Mill via Coupled CFD-DEM" *Pharmaceutics* 13, no. 7: 937.
https://doi.org/10.3390/pharmaceutics13070937