Impact of Coarse Grain Techniques on CFD-DEM Simulation of

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✓Reasonable agreement with experimental results.

✓ Parcel Contact Coarse Grain Model does not significantly affect results.

✓ RUNTIME:

T. Eppinger, F. Klippel, L. Becker, R. Aglave, D. Russ

Siemens Digital Industries Software

E-Mail: david.russ@siemens.com

Industrial processes often encompass a variety of

significant physical phenomena. This is especially true

with granular flow problems, as solid mechanics, fluid

dynamics and the interaction of the two all

contribute. While modeling techniques can capture

aspects of these problems, it is difficult to capture every

relevant phenomenon with a single technique. When

only a portion of the physics are captured, the usefulness

of such a simulation is limited. A more comprehensive

Multiphysics approach which combines multiple modeling

techniques is necessary. For granular flow problems,

CFD-DEM coupled simulations are one such approach.

A common roadblock to the widespread utilization of

coupled CFD-DEM simulation is the high computational

cost for large scale problems. Yet in an increasingly

competitive industrial environment, the opportunity cost of

missed innovation dwarfs this computational

cost. Numerical techniques such as coarse grain methods

can help reduce the computational cost and make

engineering innovation more attainable.

Spouted beds, commonly used for particle coating or drying,

are one such application to which coupled CFD-DEM

techniques are well suited. In this work, Simcenter STAR-

CCM+ was used to compare the efficacy and efficiency of

different coarse grain techniques for a spouted bed

application. Results have been compared qualitatively and

quantitative against experimental data. Bed expansion and

pressure drop are generally well predicted.

References[1] Vitalij Salikov, Sergiy Antonyuk, Stefan Heinrich, Vinayak S. Sutkar, Niels G. Deen,

J.A.M. Kuipers, Characterization and CFD-DEM modelling of a prismatic spouted bed,

Pow. Tech. 270 (2015), 622-636.

Particle Coarse GrainingSimulation SetupGeometry Setup

• 326k trimmed (hexahedral) cells

• Fully 2-way coupled DEM simulation

• 235k particles

• diameter d = 1.8 mm,

• density ρ = 1040 kg/m³ and Young‘s Modulus = 100 MPa

• Particle-particle friction and restitution coefficient: 0.5, 0.75

• Particle-wall friction and restitution coefficient: 0.9, 0.9

• Gidaspow drag law & pressure gradient

• Simulation time approx. 7s

Impact of Coarse Grain Techniques on CFD-DEM Simulation of a

Prismatic Spouted Bed

Introduction

Methods

Conclusion

Results

Comparison between CFD-DEM and experimental results.

ሶ 𝑽𝑮𝒂𝒔=

0.0

15 m

³/s

Parcel Contact Coarse Grain Model , 10 particle/parcel

No Coarse Graining

ሶ 𝑽𝑮𝒂𝒔=

0.0

23 m

³/s

No Coarse Graining

Parcel Contact Coarse Grain Model , 10 particle/parcel

ሶ𝑽𝑮𝒂𝒔=0.015 m³/s

Exp.: 5.1Hz

Exp.: pressure fluctuation

800 -1500 Pa

CFD-DEM: 3098 CPU hours

CFD-DEM with CG: 98 CPU hours

particles parcel

• Fluid-particle interaction (CFD-DEM coupling)

is calculated based on particle size

• Each particle has the same properties

• Collision simulation is done base on parcel

size and allows larger time-steps.

195

250

100

60°

Ave.

Part

icle

Heig

ht

[m]

Exp.: 0.102 m

Unrestricted

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