Direct Numerical Simulation of Reactive Fluid-Particle Systems Using an Immersed Boundary Method.

Area of Science:

• Chemical Engineering
• Fluid Dynamics
• Heat and Mass Transfer

Background:

• Coupled heat and mass transfer phenomena are crucial in various chemical processes.
• Understanding fluid-particle interactions with surface reactions is essential for reactor design.
• Dynamic boundary conditions imposed by particle temperature significantly impact system behavior.

Purpose of the Study:

• To investigate coupled heat and mass transfer in fluid-particle systems using direct numerical simulation (DNS).
• To analyze the influence of exothermic surface reactions on particle and fluid phases.
• To evaluate the performance of a one-dimensional heterogeneous reactor model against DNS results.

Main Methods:

• Direct numerical simulation (DNS) was employed to model fluid-particle systems.
• The study considered scenarios including static fluid diffusion, forced convection around a spherical particle, a three-bead reactor, and a dense particle array.
• Concentration and temperature profiles were computed and compared with theoretical models.

Main Results:

• DNS results for particle temperatures showed excellent agreement with established solutions for simpler cases.
• The study successfully simulated complex systems, including dense particle arrays.
• Concentration and temperature profiles were analyzed, highlighting heterogeneity within particle arrays.

Conclusions:

• DNS is a reliable method for studying coupled heat and mass transfer in complex fluid-particle systems.
• Particle temperature acts as a dynamic boundary condition, influencing the overall heat transfer.
• The findings provide insights into the heterogeneity of dense particle arrays and their implications for reactor modeling.