A Simple New Method for Calculating Precipitation Scavenging Effect on Particulate Matter: Based on Five-Year Data in Eastern China

A “rain-only” method is proposed to find out the precipitation effect on particle aerosol removal from the atmosphere, and this method is not only unique and novel but also very simple and can be easily adapted to predict aerosol particle scavenging over any region across the world irrespective of the topographical, orographical, and climatic features. By using this simple method, the influences of the rain intensity and particle mass concentration on the aerosol scavenging efficiency are discussed. The results show that a higher concentration, a higher rain intensity, and a larger particle size lead to a higher scavenging efficiency and a higher scavenging rate. The greater the rain intensity, the higher the scavenging efficiency. The scavenging efficiency of PM10 by precipitation is better than that of PM2.5. When the rain intensity is 10 mm h−1, the scavenging efficiency of PM2.5 reaches 5.1 μg m−3 h−1, and the scavenging efficiency of PM10 reaches 15.8 μg m−3 h−1. The scavenging rate increases faster when accumulative precipitation is below 15 mm. The scavenging rate has obvious monthly variation, and the scavenging rate of coastal areas is less than that of inland Jiangsu. The growth of the particle mass concentration after precipitation is divided into two stages: the rapid growth stage after precipitation ends, and the slow growth stage about 24 h after precipitation ends.

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Development of a real-time total suspended particle mass concentration measurement system based on light scattering for monitoring fugitive dust in construction sites

Sensors and Actuators A Physical ◽

10.1016/j.sna.2021.113017 ◽

2021 ◽

pp. 113017

Author(s):

Wooseok Sung ◽

Seong-Jae Yoo ◽

Yong-Jun Kim

Keyword(s):

Light Scattering ◽

Real Time ◽

Measurement System ◽

Mass Concentration ◽

Suspended Particle ◽

Particle Mass ◽

Total Suspended Particle ◽

Fugitive Dust ◽

Construction Sites ◽

Particle Mass Concentration

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Simulation of Volcanic Ash Ingestion Into a Large Aero Engine: Particle–Fan Interactions

Journal of Turbomachinery ◽

10.1115/1.4041464 ◽

2018 ◽

Vol 141 (1) ◽

Cited By ~ 3

Author(s):

Andreas Vogel ◽

Adam J. Durant ◽

Massimo Cassiani ◽

Rory J. Clarkson ◽

Michal Slaby ◽

...

Keyword(s):

Particle Size ◽

Stream Flow ◽

Mass Concentration ◽

Volcanic Ash ◽

Particle Mass ◽

Core Flow ◽

Turbine Engine ◽

The Core ◽

Core Section ◽

Particle Mass Concentration

Volcanic ash (VA) clouds in flight corridors present a significant threat to aircraft operations as VA particles can cause damage to gas turbine engine components that lead to a reduction of engine performance and compromise flight safety. In the last decade, research has mainly focused on processes such as erosion of compressor blades and static components caused by impinging ash particles as well as clogging and/or corrosion effects of soft or molten ash particles on hot section turbine airfoils and components. However, there is a lack of information on how the fan separates ingested VA particles from the core stream flow into the bypass flow and therefore influences the mass concentration inside the engine core section, which is most vulnerable and critical for safety. In this numerical simulation study, we investigated the VA particle–fan interactions and resulting reductions in particle mass concentrations entering the engine core section as a function of particle size, fan rotation rate, and for two different flight altitudes. For this, we used a high-bypass gas-turbine engine design, with representative intake, fan, spinner, and splitter geometries for numerical computational fluid dynamics (CFD) simulations including a Lagrangian particle-tracking algorithm. Our results reveal that particle–fan interactions redirect particles from the core stream flow into the bypass stream tube, which leads to a significant particle mass concentration reduction inside the engine core section. The results also show that the particle–fan interactions increase with increasing fan rotation rates and VA particle size. Depending on ingested VA size distributions, the particle mass inside the engine core flow can be up to 30% reduced compared to the incoming particle mass flow. The presented results enable future calculations of effective core flow exposure or dosages based on simulated or observed atmospheric VA particle size distribution, which is required to quantify engine failure mechanisms after exposure to VA. As an example, we applied our methodology to a recent aircraft encounter during the Mt. Kelud 2014 eruption. Based on ambient VA concentrations simulated with an atmospheric particle dispersion model (FLEXPART), we calculated the effective particle mass concentration inside the core stream flow along the actual flight track and compared it with the whole engine exposure.

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