Particulate Deposit Shape Evolution on Cylinders in Cross-Flow at High Stokes Numbers

A numerical study of the effects of loading from diffusive deposition on the efficiency of fibrous filters

“…The models of dendrite growth by Payatakes and colleagues, Payatakes et al (1977), Payatakes and Gradon (1980), which are limited due to the neglect of the effects of the dendrite upon the flow field. The theoretical studies of Konstandopoulos et al (1998) and Kostoglou and Konstandopoulos (2000) considered the shape evolution of particulate deposits on cylinders. In the paper by Konstandopoulos et al (1998) the case of inertial deposition on an isolated cylinder in potential flow was studied.…”

“…The Boundary Element Method was adopted to compute the flow past the cylinder with and without deposition. In the paper of Kostoglou and Konstandopoulos (2000) the deposit evolution on a cylinder was considered for inertial impaction in the limit of high Stokes number. Other studies which attempt to take into account the change in the flow field due to the particle deposit are restricted due to their considerable use of computing time and resources, see Jung and Tien (1993), Biggs et al (2003), Karadimos and Ocone (2003) and Przekop et al (2003).…”

A Dynamic Model for the Normal Impact of Fly Ash Particle with a Planar Surface

“…Moreover, the ash deposition has undesirable consequences on heat transfer, increases pressure drop, interferes aerodynamically with the flow and causes heat estranger pipe corrosion through the uptake and retention of corrosive, condensable vapors by the fouled surface. All these effects translate into overall plant efficiency losses, high operating/maintenance costs and reduced availability of the units [3]. Ash deposition is defined as the accumulation of ash particles on a heat exchange surface that is essentially a particle-surface process.…”

“…Kinetic models can predict the capture velocity, the relationship between restitution coefficient and incident velocity, and critical velocities. Kinetic models have been extensively used in studies such as hard-sphere discrete element method (DEM) simulations [12,17]. However, kinetic models can hardly reveal the dynamic features of the impact process, in terms of time-variant contact force, particle velocity, deformation and the relationships between them, etc.…”

Numerical investigation into the loading behaviour of filters operating in the diffusional and interception deposition regimes

“…This approach although primarily considering a single fibre, takes into account the effects of the neighbouring fibres and is described in more detail in the following section. Many different numerical approaches have been adopted to solve the flow equations including the Boundary Element Method (BEM), see for example Hildyard et al (1985) and Konstandopoulos (2000), the control volume method, see for example Li and Marshall (2007) and Qian et al (2009) and the lattice-Boltzmann approach, Filippova and Hanel (1997) and Przekop et al (2003). Once the flow field is determined the movement of particles within the filter and their possible removal by the fibres can be investigated.…”