When a solid sphere drops in a granular medium, an impact crater is created. The penetration of the projectile in the granular bed as a function of the impact energy is evaluated theoretically using a simple model including a friction law between the projectile and the grains, a viscous dissipation in the bed and a force from the collisions between the projectile and the granular material. This...

A packed-bed membrane reactor in a distributor configuration is studied theoretically for the oxidative propane dehydrogenation and compared with fixed-bed reactor. Based on detailed 2D models considering two different heat mass transport scale-up including various reactor-to-particle diameter ratios (D/dP) analyzed respect to performance, transfer hot spot formation. Higher selectivities at lo...

The rapid depletion of oil and the environmental impact of combustion has motivated the search for clean combustion technologies. Fluidised bed combustion (FBC) technology works by suspending a fuel over a fast air inlet whilst sustaining the required temperatures. Using biomass or a mixture of coal/biomass as the fuel, FBC provides a low-carbon combustion technology whilst operating at low tem...

Iterative reconstructions for clinical PET must run fast. We describe a clinical processing method based on sinogram rebinning, Fourier rebinning for the 3D to 2D data reduction, and iterative reconstruction using the attenuation-weighted OSEM method with a projector based on a gaussian pixel model. When this approach is used, multi-bed clinical oncology scans can be ready for diagnosis within ...

Adaptive grid refinement is a critical component of the improvements that have recently been made in algorithms for the numerical solution of partial differential equations (PDEs). The development of new algorithms and computer codes for the solution of PDEs usually involves the use of proof-of-concept test problems. 2D elliptic problems are often used as the first test bed for new algorithms a...

Fluidized beds have been widely used in power generation and in the chemical, biochemical, and petroleum industries. The 3D simulation of commercial scale fluidized beds has been computationally impractical due to the required memory and processor speeds. However, in this study, 3D Computational Fluid Dynamics simulation of a gas-solid bubbling fluidized bed is performed to investigate the effe...

Adaptive grid refinement is a critical component of the improvements that have recently been made in algorithms for the numerical solution of partial differential equations (PDEs). The development of new algorithms and computer codes for the solution of PDEs usually involves the use of proof-of-concept test problems. 2D elliptic problems are often used as the first test bed for new algorithms a...