BIOLOGICAL AGENT DISPERSAL

  • Overview
    • Understanding the importance understanding how airborne particles behave
    • Computer models to describe open air release of Anthrax
  • Creation of 300 m x 100 m testing facility
    • Determine distance traveled based on spore size and wind speed
    • Determine important parameters for facility to safely control dispersion
  • Importance of the problem to society
    • Immediate bio-terror-threat response training
    • Contamination remediation for first responders
    • Future response plans including timely contamination zone determination
  • This must be researched in order to plan for an undesirable event

GLASS PLATE SIMULATION RESULTS

  • Basic 2” diameter, 18” tall nozzle
  • 5 m/s particle exit velocity
  • 1 kg/ 15 min mass flow rate
  • 1, 5, and 10 mph wind speeds
  • Particles stick where they land
  • 1x, 2x, 4x, 8x, and 16x particles
  • Ideal Mesh
    • Verified by mesh study
    • Polyhedral mesh
    • Prism layers
Max flux phase
Project projectory diagram
Table of results

RESEARCH AND DEVELOPMENT

  • Modeling Anthrax spore size and density
    • 1.2 x 5 μm [1]
    • 1.165 g/ml [2]
  • Relative particle size
    • 1.52×1014 spores/Kg
  • Drag Coefficient
    • Dominant viscous terms
    • Re of 0.32-16.2
  • Pollen similarity studies
    • Viable spores 40 km offshore [3]
  • Particle packing
    • Packing density of 0.64 [4
  • Environmental conditions
    • Idaho Falls
    • Avg. winds 7.4 - 9.6 mph
    • Avg. humidity 61% [5]
objects at micron scale

LARGE SCALE SIMULATIONS

  • Open air model
  • Realistic wind gusts
    • Causes vortex tripping
  • Obstacles
    • Berms around testing facility
      • Variable sizes
        • Higher berms create larger negative pressure traps
    • Cars in a stadium parking lot
      • Causes vortex tripping
dispersal diagram track time diagram
Biological dispersion diagram Velocity Biological dispersion diagram 2 Velocity

FUTURE WORK

  • The creation and testing of a prototype
  • Use of detached eddy simulation (DES)
  • Further investigation of several principles
    • Spore sedimentation
    • Thermophoresis
    • Spore interaction
    • Validate clumping models
    • Realistic cross winds
Skier with dispersion effect

Special Thanks To:

  • Jake Israelsen
  • Chris Springmeyer
  • Will Wightman
  • Camiel Zorn
  • Idaho National
  • Laboratory
  • Michal Hradisky

References

  • Journal of Clinical Pathology and Journal of Applied Microbiology
  • Research and Technology Directorate of the Edgewood Chemical Biological Center at the U.S. Army Aberdeen Proving Ground
  • NSF funded National Evolutionary Synthesis Center in North Carolina, 2010
  • College of Engineering, Peking University, Beijing 100871, China, 2010
  • Time and Date. Climate and Weather Averages in Idaho Falls, Idaho, USA. Published 2019