A Coupling Algorithm for Eulerian Lagrangian Simulation of

A Coupling Algorithm for Eulerian. Lagrangian Simulation of Dense Gas. Solid Reacting Flows on Unstructured Mesh Jian Cai Assistant Professor University of Wyoming jcai@uwyo. edu

Combustion research at UW q New combustion program □ Mechanical Engineering Department □ Four junior faculty members □ Coal utilization q Research topics □ Laser spectroscopy □ Turbulent combustion experiments and modeling □ Pulverized and dense coal combustion □ Radiation modeling and measurements 2

Coal combustion and gasification q What is the limiting factor for accuracy? q What is the next limiting factor? 3 Turbulence Radiation Chemistry Multiphase

E-L models for multiphase flows q Advantages in accounting for changes of □ Particle size and distribution § Heat transfer § Heterogeneous reactions □ History between different particles § Composition § Temperature q Disadvantages □ Computational cost □ Unknown surface properties 4

Open. FOAM q Lagrangian existing capabilities □ Pulverized coal combustion □ Collisional non-reacting particles q Eulerian □ Solving transport equations □ Needs a new coupling algorithm 5

FVM: unstructured collocated mesh 6

Coupled equations 7 Model Coupling variables Incompressible U, p Compressible U, p, T, ρ Multiphase compressible U, p, T, ρ, ε

Coupling algorithm Density update Energy, species equations + Equation of state Velocity-pressure coupling 8

Reacting test case q Pseudo 2 D q DPM q Char 2. 5 mm q 24750 parcels q 3 s physical time 9

CFB q Zhou et al CES 1994 1995 q MPPIC q Sand 213µm q 0. 3 Mparcel x 1000 p/parcel 10

Particle volume fraction 11

Conclusions q Eulerian-Lagrangian coupling algorithm □ Unstructured collocated mesh □ Gas-solid dense reacting flows q Computational cost is the major limitation □ MPPIC faster than DPM 12