Air Filter Pleat Flow Simulations With Monte Carlo Particle Deposition

1997 ◽  
Author(s):  
Curtis M. Vickery
Keyword(s):  
Monte Carlo ◽  
Particle Deposition ◽  
Volumetric Flow Rate ◽  
Spherical Particles ◽  
Darcy Law ◽  
Air Filter ◽  
Filter Performance ◽  
Design Engineers ◽  
Drag Forces ◽  
Laminar Air Flow

Abstract Automotive air filter pleat parameters must often be estimated by design engineers, affecting overall filter performance. This paper examines pressure-flow response of and particle deposition upon three different pleat profiles. Pleat models, analysis operating point, and analysis parameters were based on a Purolator automotive air filter application. Computational assumptions included steady state, incompressible, isothermal, laminar air flow with a modified/extended Darcy law equation used for media flow computations. Inlet velocities were set to maintain the filter rated volumetric flow rate with equal pressure drop through each pleat model. 1–50 micron diameter spherical particles were used in Monte Carlo particle deposition analyses. Once introduced into the computed flow fields, particle trajectories were computed assuming inertial, body, buoyancy, and drag forces were active. Histograms depicting particle starting and deposition locations were constructed for five particle size sub-classes. Flow field and structural influences on particle deposition tendencies were noted.

scholarly journals Gray Box Time Variant Clogging behaviour and Pressure Drop Prediction of the Air Filter in the HVAC System

2021 ◽  
Vol 246 ◽  
pp. 10002
Author(s):  
Hossein Alimohammadi ◽  
Kristina Vassiljeva ◽  
Eduard Petlenkov ◽  
Martin Thalfeldt ◽  
Alo Mikola ◽  
...  
Keyword(s):  
Pressure Drop ◽  
Particle Deposition ◽  
Membrane Filter ◽  
Volumetric Flow Rate ◽  
Automation System ◽  
Time Varying ◽  
Air Filter ◽  
Bee Colony ◽  
Noisy Signals ◽  
Hvac Filters

Identification and prediction of clogging behavior in heating, ventilation, and air conditioning (HVAC) filters is crucial to avoid issues such as system overheating, energy waste, lower indoor air quality, etc. Researchers are focusing more on the particle loading characteristics of a filter medium in a laboratory environment under steady-state conditions, fixed particle concentrations, area of porosity, dust feed and volumetric flow rate. However, recent research still shows uncertainties in modeling as well as the implementation problems of constructing the HVAC laboratory test bench and equipment. In addition, subjects such as non-uniform particle deposition depreciation of the condition and various type of mechanical filters such as fibrous, fabric, granular, and membrane filter or electrostatic filters which typically used in HVAC systems perform under some assumptions and still need more research. The studies become even more difficult acquiring a large number of time-varying and noisy signals. Another approach among studies is data-driven knowing that Building Automation System (BAS) is not equipped with appropriate sensor measuring the clogging, it is needed to drive the clogging mathematical model from the pressure drop signal. This paper bridges the gap between particle-size study and black box modeling of HVAC filter which has not received much attention from authors. The proposed method assumes that the pressure drop is the result of two time-varying functions; f(t), which represents the dynamics of clogging and, g(t), which refers to dynamics of remained terms. The exponential and polynomial of second order functions are proposed to express the clogging behavior. The software package based on Particle Swarm Optimization Artificial Bee Colony (PSOABC) algorithm, is developed and implemented to estimate the coefficients of the clogging functions based on smallest RMSE, high coefficient of correlation and acceptable tracking. Five Air Handling Unit (AHUs) are selected for practical verification of the model and the results show that the applied method can successfully predict clogging and pressure drop behaviour of HVAC filters.

scholarly journals Clusters Formed by Dumbbell-like One-Patch Particles Confined in Thin Systems

2021 ◽  
Author(s):  
Masahide Sato
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Particle Interaction ◽  
Three Dimensional ◽  
The Other ◽  
Spherical Particles ◽  
Dimensionless Distance ◽  
Large Island ◽  
Cluster Shape

Abstract Performing isothermal-isochoric Monte Carlo simulations, I examine the types of clusters that dumbbell-like one–patch particles form in thin space between two parallel walls, assuming that each particle is synthesized through the merging of two particles, one non-attracting and the other attracting for which, for example, the inter-particle interaction is approximated by the DLVO model. The shape of these dumbbell-like particles is controlled by the ratio of the diameters q of the two spherical particles and by the dimensionless distance l between them. Using a modified Kern–Frenkel potential, I examine the dependence of the cluster shape on l and q. Large island-like clusters are created when q < 1. With increasing q, the clusters become chain-like. When q increases further, elongated clusters and regular polygonal clusters are created. In hte simulations, the cluster shape becomes three-dimensional with increasing l because the thickness of the thin system increases proportionally to l.

scholarly journals Fiberglass Vs. Synthetic Air Filtration Media

2002 ◽  
Vol os-11 (3) ◽  
pp. 1558925002OS-01 ◽  
Author(s):  
Edward Vaughn ◽  
Gayetri Ramachandran
Keyword(s):  
Research Work ◽  
Test Methods ◽  
Air Filtration ◽  
Filter Media ◽  
Air Filter ◽  
Filter Performance ◽  
And Performance ◽  
Synthetic Media

This paper deals with ASHRAE filters used in air filtration applications and summarizes, on the basis of current research work, some of the reasons for the disagreement that exists among filter manufacturers concerning the properties and performance of various types of air filter media in general, glass and synthetic media in particular. Attention is also drawn to some important items that need to be incorporated in test methods and to some factors that could be affecting filter performance

scholarly journals Clusters formed by dumbbell-like one-patch particles confined in thin systems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Masahide Sato
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Particle Interaction ◽  
Three Dimensional ◽  
The Other ◽  
Spherical Particles ◽  
Dimensionless Distance ◽  
Large Island ◽  
Cluster Shape

AbstractPerforming isothermal-isochoric Monte Carlo simulations, I examine the types of clusters that dumbbell-like one–patch particles form in thin space between two parallel walls, assuming that each particle is synthesized through the merging of two particles, one non-attracting and the other attracting for which, for example, the inter-particle interaction is approximated by the DLVO model . The shape of these dumbbell-like particles is controlled by the ratio of the diameters q of the two spherical particles and by the dimensionless distance l between these centers. Using a modified Kern–Frenkel potential, I examine the dependence of the cluster shape on l and q. Large island-like clusters are created when $$q<1$$ q < 1 . With increasing q, the clusters become chain-like . When q increases further, elongated clusters and regular polygonal clusters are created. In the simulations, the cluster shape becomes three-dimensional with increasing l because the thickness of the thin system increases proportionally to l.

Small-angle scattering from collections of interacting hard ellipsoids of revolution studied by Monte Carlo simulations and other methods of statistical thermodynamics

1999 ◽  
Vol 32 (5) ◽  
pp. 917-923 ◽  
Author(s):  
Bo Sjöberg
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Simulations ◽  
Small Angle ◽  
Chemical Potential ◽  
Compressibility Factor ◽  
Particle Method ◽  
Spherical Particles ◽  
Angle Scattering ◽  
Approximation Formulas ◽  
Experimental Values

Computer simulations using Monte Carlo methods are used to investigate the effects of interparticle correlations on small-angle X-ray and neutron scattering from moderate or highly concentrated systems of ellipsoids of revolution. Both oblate and prolate ellipsoids, of varying eccentricities and concentrations, are considered. The advantage with Monte Carlo simulation is that completely general models, both regarding particle shapes and interaction potentials, can be considered. Equations are also given that relate the nonideal part of the chemical potential, βμni, with the scattering at zero angle,I(0), and the compressibility factor,z. The quantity βμnican be obtained during the Monte Carlo simulations by using Widom's test-particle method. For spherical particles, the simulations are compared with approximation formulas based on the Percus–Yevick equation. A method is also suggested for the calculation of both βμniandzfrom experimental values ofI(0) recorded as a function of concentration.

Methods of simulating random patterns of non-spherical objects and their application

1996 ◽  
Vol 28 (02) ◽  
pp. 342-343
Author(s):  
Masaharu Tanemura
Keyword(s):  
Monte Carlo ◽  
Markov Chain ◽  
Markov Chain Monte Carlo ◽  
Spatial Patterns ◽  
Hard Core ◽  
Spherical Particles ◽  
Finite Region ◽  
Uniform Sampling ◽  
Regular Manner ◽  
Random Patterns

We consider two mechanisms for simulating spatial patterns of hard-core non-spherical particles, namely the random sequential packing (RSP) and the Markov chain Monte Carlo (MCMC) procedures. The former is described as follows: we put a particle one-by-one into a finite region by sampling its location x and direction θ uniformly at random; if it does not overlap with other particles put before, it is put successfully, otherwise, we discard it and try another uniform sampling of (x, θ); by repeating the above, we can obtain a set of non-overlapping particles. The MCMC procedure is the following: we first give a certain non-overlapping pattern of non-spherical particles prepared in a random or a regular manner; then we select a particle and sample its new trial location x and direction θ at random; if the new sample (x, θ) is accepted, i.e. it does not overlap with other particles, the selected particle is moved to the new ‘position’, otherwise the particle is retained at the old position; by repeating the above, a series of a set of non-overlapping particles is generated.

A Monte Carlo Approach to Prediction of Extreme Response Statistics of Drag Dominated Offshore Structures

2007 ◽  
Author(s):  
A. Naess ◽  
O. Gaidai
Keyword(s):  
Monte Carlo ◽  
Weather Conditions ◽  
Offshore Structures ◽  
Drag Forces ◽  
Wave Elevation ◽  
The Monte Carlo Method ◽  
Strong Current ◽  
Highly Nonlinear ◽  
Extreme Response

The focus of the present paper is the extreme response statistics of drag dominated offshore structures subjected to harsh weather conditions. More specifically, severe sea states both with and without strong current are considered. The nature of the hydrodynamic forces acting on the structure becomes highly nonlinear. Additionally to the drag forces, the so called inundation effect due to the wave elevation, corrected to include second order waves, is also taken into account. In the present paper the Monte Carlo method along with a special extrapolation technique is applied. The proposed method opens up the possibility to predict simply and efficiently long-term extreme response statistics, which is an important issue for the offshore structures design.

Interaction and Wall Corrections for the Slow Motion of Two Fluid or Solid Particles Parallel to the Axis of a Circular Cylinder through a Viscous Fluid

1980 ◽  
Vol 22 (5) ◽  
pp. 243-249 ◽  
Author(s):  
T. Greenstein
Keyword(s):  
Circular Cylinder ◽  
Solid Particle ◽  
Particle System ◽  
Slow Motion ◽  
Solid Particles ◽  
Spherical Particles ◽  
Cylinder Wall ◽  
Characteristic Distance ◽  
Direction Parallel ◽  
Drag Forces

Numerical values are provided which enable the drag force on the reference spherical fluid or solid particle, and the torque on the reference spherical solid particle, to be computed for the particular case when two spherical particles move in a direction parallel to their line of centres parallel to the axis of a circular cylinder. Results for this motion are also expressed in terms of the ratio of drag forces experienced by (1) the particle of arbitrary shape in a bounded, two particle system, and the particle in an unbounded, two particle system, and (2) the particle in a bounded, two particle system, and the particle moving alone with the same speed and orientation in the same, but unbounded, fluid. The computation furnishes the interaction and wall corrections correctly to the first-order in the ratios of characteristic particle dimension to characteristic distance of the particle from both another particle and from the cylinder wall. The axisymmetric problem was extended to the more general case where the two particles may be placed eccentrically within the cylinder and the torque was also computed. Furthermore, the two particles may be fluid droplets as well as solid particles.

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