Analysis of the flow field and pressure drop in fixed-bed reactors with the help of lattice Boltzmann simulations

2002 ◽  
Vol 360 (1792) ◽  
pp. 507-520 ◽  
Author(s):  
Thomas Zeiser
Keyword(s):  
Pressure Drop ◽  
Flow Field ◽  
Lattice Boltzmann ◽  
Fixed Bed ◽  
Fixed Bed Reactors ◽  
Lattice Boltzmann Simulations

scholarly journals DEM--CFD modeling and simulations of hydrodynamic characteristics and flow resistance coefficient in fixed-bed reactors

2021 ◽  
Author(s):  
Yaping Li ◽  
Le Xie ◽  
Yonghua Zhou ◽  
Chongwen Jiang ◽  
Hong Zhong
Keyword(s):  
Pressure Drop ◽  
Flow Resistance ◽  
Fixed Bed ◽  
Resistance Coefficient ◽  
Spherical Particles ◽  
Hydrodynamic Characteristics ◽  
Model Parameters ◽  
Large Set ◽  
Fixed Bed Reactors ◽  
Fixed Beds

The ability to predict void fraction, pressure drop, and flow resistance coefficient in fixed-bed reactors is significant to their optimal design. In this study, the discrete element method (DEM) is combined with computational fluid dynamics (CFD) to simulate the hydrodynamic characteristics of fixed-beds. A realistic random packing structure for fixed-beds with spherical particles was generated via the DEM method and then meshed using Ansys ICEM software for the CFD simulation. A grid independency study was performed to select appropriate grid model parameters. A large set of numerical experiments was conducted to investigate the hydrodynamic characteristics with respect to different inlet velocities and particle sizes, and the simulated pressure drop data were used to calculate the flow resistance coefficient. The output flow resistance coefficients agreed well with those calculated by the classical models in laminar and turbulent flow regimes, thereby indicating the accuracy and advantage of the proposed DEM–CFD approach.

Conversion Enhancement of Fixed-Bed Reactors Using Two-Dimensional Hollow Cylindrical Catalyst Pellet

2013 ◽  
Vol 11 (1) ◽  
pp. 159-168 ◽  
Author(s):  
Mohammad Asif
Keyword(s):  
Pressure Drop ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Two Dimensional ◽  
Concentration Gradients ◽  
Fixed Bed Reactors ◽  
Catalyst Pellet ◽  
Conversion Level ◽  
Catalyst Pellets ◽  
Rigorous Model

Abstract The key challenge in the operation of any industrial fixed-bed heterogeneous reactor is to enhance the conversion level while keeping the pressure-drop low. Towards this end, the use of finite hollow cylindrical catalyst pellets instead of spherical ones is proposed here. The absence of the pellet core helps to lower the effect of the internal mass transport resistance besides providing a greater surface area. Another equally important advantage is a lower pressure-drop due to the higher bed void fraction associated with hollow pellets. A rigorous model of the heterogeneous fixed-bed reactor containing finite hollow cylindrical catalyst pellet is presented here accounting for the concentration gradients both in the axial as well as the radial directions, thus, resulting in a two-dimensional partial differential equation for the solid catalytic phase.

BENCHMARK ANALYSIS AND APPLICATION RESULTS FOR LATTICE BOLTZMANN SIMULATIONS ON NEC SX VECTOR AND INTEL NEHALEM SYSTEMS

2009 ◽  
Vol 19 (04) ◽  
pp. 491-511 ◽  
Author(s):  
THOMAS ZEISER ◽  
GEORG HAGER ◽  
GERHARD WELLEIN
Keyword(s):  
Porous Medium ◽  
Flow Field ◽  
Lattice Boltzmann ◽  
Optimization Approach ◽  
Excellent Performance ◽  
Flow Solver ◽  
Benchmark Analysis ◽  
Vector Systems ◽  
Lattice Boltzmann Simulations ◽  
Memory Subsystem

Classic vector systems have all but vanished from recent TOP500 lists. Looking at the recently introduced NEC SX-9 series, we benchmark its memory subsystem using the low level vector triad and employ the kernel of an advanced lattice Boltzmann flow solver to demonstrate that classic vectors still combine excellent performance with a well-established optimization approach. To investigate the multi-node performance, the flow field in a real porous medium is simulated using the hybrid MPI/OpenMP parallel ILBDC lattice Boltzmann application code. Results for a commodity Intel Nehalem-based cluster are provided for comparison. Clusters can keep up with the vector systems, however, require massive parallelism and thus much more effort to provide a good domain decomposition.

Sign in / Sign up

Export Citation Format

Share Document