All the initial collection efficiency models in this section were developed for downflow filtration and are composed of the sum of the three transport mechanisms ([eta] = [[eta].sub.D] = [[eta].sub.I] = [[eta].sub.G]), diffusive transport ([[eta].sub.D]); interception ([[eta].sub.I]) and gravitational settling ([[eta].sub.G]).
The modified term is gravity sedimentation (gravitational settling) [[eta].sub.G], based on the direction of the flow, i.e., upflow or downflow.
Gravitational settling and suspension of particles has been under intense examination in the past as it is important to many areas of engineering and environmental sciences.
Gravitational settling of aerosol particles in randomly oriented cellular flow fields, Journal of the Atmospheric Sciences, Vol.
The dry deposition velocities are calculated as a function of particle size, density, friction velocity, and surface characteristics and they include the contributions of turbulent transfer, Brownian diffusion, impaction, interception, gravitational settling, and particle rebound [15, 16].
For the smallest clay and silt particles as shown in Table 1, inertial impaction, interception, and gravitational settling plays the dominant role.
At the same time, there are ramifications associated with condensed solar matter, especially with respect to gravitational settling
, solar activity, and nucleosynthesis.
Superior filtration is achieved first through inertial impaction, secondly through gravitational settling
, and thirdly through a nearly vertical coalescing multi-stage filter element with efficiencies of 0.03 micron and higher.
The baffle boxes employ gravitational settling
of suspended solids to achieve pollutant removal from stormwater.