Investigation of a Technique for Clearing and/or Modifying a Military Smoke Cloud
Abstract
A numerical model is applied to assess the smoke particle (0.1 < R sub p < 5.0 micrometers) scavenging by an oblate spheroid in the range of Reynolds numbers 0.1 < Re sub c < 50. The calculated collision efficiency is between 0.3% and 4.0%. The collision efficiency of a charged thin spheroid (Q sub c = 2 e.s.u./sq. cm) colliding with smoke particles of R sub p = 0.3 micrometers is 14% for Re sub c = 50. Experimental study of the smoke particle deposition on disks in the range of 80 < Re sub C < 320 in an aerodynamic wind tunnel leads to the following conclusion: Collection efficiencies of stationary (or steady settling) disks are between 0.5 and 2.0%. For disks oscillating at a frequency simulating the falling disk in the atmosphere, the collection efficiency is 20% higher. Collection efficiency of electrically charged disks (0.57 < Q sub c < 2.86 e.s.u./sq. cm) is between 3% and 14%. Deposition of particulates with R sub p < 0.35 micrometer is higher on the disk's back side than on the front side. Charged cylinders are featured by a collection efficiency between 0.3% to 5.0% for 3.5 < Re sub c < 26 and potential differences from 1 kV to 8 kV. High collection efficiencies are found on charged grid (several percent for 1 kV and more than 5% for 5 kV). The effect of falling scavenger zone is considered to be more important for the scavenger's fall velocity and its collection efficiency than for scavenger dispersion.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1986
- Accession Number
- ADA171161
Entities
People
- Josef Podzimek