Particle accumulation in square duct cavity with laminar flow: A four-way coupled CFD-DEM investigation of effects of particle-to-fluid density ratio and fluid Reynolds number using model validated against experimental setup

Particle accumulation in square duct cavity with laminar flow

Ehlers, Anders Riishede ; Agesen, Andreas Overgaard ; Blæsbjerg, Line Dyhr Damsgaard

4. term

Energy Engineering, Master

2019

176

Dette projekt udvikler en computermodel til at undersøge, hvordan partikler ophobes, når en væske strømmer gennem en enkel geometri. Geometrien er en kvadratisk kanal med en blok over et hulrum, som i starten er fyldt med partikler. Modellen er baseret på et four-way-koblet CFD-DEM-rammeværk (Computational Fluid Dynamics–Discrete Element Method), som beskriver både væskestrømmen og de enkelte partikler og medtager vekselvirkninger mellem væske og partikler samt kollisioner mellem partikler. CFD-DEM-modellen valideres mod eksperimentelle data ved hjælp af videooptagelser, og strømningshastigheder måles med Particle Image Velocimetry (PIV), en kamerabaseret metode. En parametrisk undersøgelse af forholdet mellem partikel- og væsketæthed og Reynolds-tal (et dimensionsløst mål for strømningsforhold) viser, at stigende Reynolds-tal mindsker den normaliserede friktionsfaktor (et mål for strømningsmodstand), andelen af partikler der bliver i hulrummet, og ophobningens hældningsvinkel, mens et højere tæthedsforhold øger alle tre.

This project develops a computer model to study how particles build up when a liquid flows through a simple geometry. The setup is a square duct with a block over a cavity that is initially filled with particles. The model uses a four-way coupled CFD-DEM framework (Computational Fluid Dynamics–Discrete Element Method) to represent both the fluid flow and many individual particles, including two-way fluid–particle effects and particle–particle collisions. The CFD-DEM model is validated against experiments using video recordings, and flow speeds are measured with Particle Image Velocimetry (PIV), a camera-based technique. A parametric study varying the particle-to-fluid density ratio and the Reynolds number (a dimensionless measure of flow conditions) shows that increasing the Reynolds number reduces the normalised friction factor (a measure of flow resistance), the fraction of particles remaining in the cavity, and the inclination angle of the particle accumulation, while increasing the density ratio raises all three.

[This abstract was generated with the help of AI]

CFD ; DEM ; CFDEM ; CFD-DEM ; four-way coupled ; particle accumulation ; cavity ; laminar flow ; square duct ; eulerian-lagrangian ; granular flow ; sedimentation ; agglomeration ; PIV ; validation ; Liggghts ; OpenFOAM

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