Evaluation of steady flow profiles in rectangular and circular packed beds by a variational method

Vortmeyer, D.; Schuster, Joachim

doi:10.1016/0009-2509(83)85026-x

Cited by 286 publications

(113 citation statements)

References 17 publications

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“…In establishing these equations some classic hypotheses, such as that the fluid velocity profile is flat, are assumed. Velocity profiles within a packed bed, as reported in the literature (Fahien and Stankovich, 1979;Vortmeyer and Schuster, 1983;Zotin a nd Freire, 1986;Negrini et al, 1999), are strongly affected by the voidage distribution in the bed. The high-velocity zones correspond to the high voidage regions and upon increasing the flow, the peak velocities become more pronounced.…”

Section: Introductionmentioning

confidence: 74%

Concurrent drying of soybean seeds: the effect of the radial air profile

Assis

Lira

Murata

et al. 2005

Braz. J. Chem. Eng.

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-The aim of this work was to analyze the heat and mass transfer between the air and soybean seeds in a concurrent moving bed dryer with an air profile that is not flat. The modelling of heat and mass transfer in moving bed dryers is generally based on the application of mass and energy balance equations for both solid and fluid phases (two-phase model). In the establishment of these equations some classical hypotheses such as that the fluid velocity profile is flat, are assumed. The main goal of this work was to verify the validity of this assumption by means of an experimental and simulation study in a concurrent moving bed, using soybean seeds as particles. In this work, the radial air profile was taken into account by means of a suitable empirical correlation and a mechanistic model validated by experimental results. The numerical solution of the onedimension boundary value problem was obtained by means of a computational code based on axial integration through the DASSL code. By comparison of the experimental data and the simulated responses for air temperature and seed moisture content, it was possible to verify the significant effect of air velocity distribution.

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Section: Introductionmentioning

confidence: 74%

Concurrent drying of soybean seeds: the effect of the radial air profile

Assis

Lira

Murata

et al. 2005

Braz. J. Chem. Eng.

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“…However, measurements of fluid flow velocity above a packed bed carried out by Negrini et al [35] demonstrated clearly that the applicability of continuum mechanic approaches depends strongly on the ratio of the overall packed bed size to particle dimensions (D/d p ). They claimed that correlations including conservation of mass as employed by Fahien and Stankovic [36], Schwartz and Smith [37], Vortmeyer and Schuster [38], and Mueller [39] predict the velocity distribution adequately for high D/d p ratios, although their measurements and predictions still deviated considerably. For low D/d p ratios, the flow behaviour is determined by the anisotropic structure of the porous matrix, which leads to a rather discontinuous variation of the velocity field.…”

Section: One-phase (Homogeneous) Modelsmentioning

confidence: 99%

Simulation of thermal conversion of solid fuel by the discrete particle method

Peters¹,

Džiugys²,

Navakas³

2011

Lith. J. Phys.

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We introduce the discrete particle method (DPM) that derives from the discrete element method (DEM). This is an advanced numerical simulation tool that takes into account both motion and chemical conversion of granular material, such as coal or biomass, in furnaces in conjunction with computational fluid dynamics (CFD). However, predictions of solely motion or conversion in a decoupled mode are also applicable. The DPM uses object oriented computational techniques that support objects representing three-dimensional particles of various shapes, size, and physical properties of particle material. This makes DPM a highly versatile tool in dealing with a variety of problems related to different industrial applications of granular matter. A review of literature concerning different approaches to mass and heat transfer in packed beds is presented.

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“…The literature abounds with experimental investigations in progress on the distribution of velocities, pressure drop and heat transfer at different Reynolds numbers for different configurations of packed beds (e.g., Vortmeyer & Schuster, 1983;Eigenberger & Bey, 1996). With the proposed numerical scheme it is possible to resolve the structure of three-dimensional flow around 300 randomly distributed particles in a cylindrical tube.…”

Section: Numerical Simulation Of Local Momentum Transfer In Packed Bedsmentioning

confidence: 99%

Overlapping grids for the simulation of particle interaction at the micro scale

Nirschl

2005

China Particuology

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This paper describes the use of overlapping grids for the calculation of flow around single and multipleparticle configurations at the micro scale. The basic equations for calculation are those for conservation of mass and momentum which are solved using a common Finite-Volume formulation. The hydrodynamic particle-particle and particle-wall interaction can be calculated by using an overlapping or Chimera grid scheme. With the grid structuring procedure it is possible to use simple and structured grids around the particles and the overall main grid geometry. The particle grids are lapped over the main grid such that they can move independently after each time step without remeshing the whole geometry. The paper gives results for the validation of the code developed for general test cases, for a rotating ellipsoid in simple shear flow, the flow around particles attached to a wall, the motion of a particle in the vicinity of a wall and some results for the flow through a packed bed configuration.

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Evaluation of steady flow profiles in rectangular and circular packed beds by a variational method

Cited by 286 publications

References 17 publications

Concurrent drying of soybean seeds: the effect of the radial air profile

Concurrent drying of soybean seeds: the effect of the radial air profile

Simulation of thermal conversion of solid fuel by the discrete particle method

Overlapping grids for the simulation of particle interaction at the micro scale

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