Particle Size Quantification in Large Scale Chemical Releases Using Optical Methods
Abstract
The potential hazards of the transportation of chemicals via rail, road and sea are becoming of interest to many governmental agencies and first responders. This interest is being driven by recent accidents, the increased volume of transportation and because of domestic/international threats. As recent rail accidents have shown, the accidental release of hazardous chemicals can have a significant impact both from loss of life and economic loss standpoints. In the event of a release, protection of the public from these hazards requires real time analysis. Computational simulations are widely used for this analysis; however the key in an emergency is the speed at which the hazard assessment can be made. Reduced order models are computational codes that simplify the governing equations to gain speed at the expense of not fully accounting for the chemistry and physics of a flow field. Instead these techniques rely on experimentally derived parameters and/or correlations which simulate the physics and chemistry. In many cases the chemicals of interest are highly volatile and/or caustic. They may undergo rapid changes in particle/droplet conditions (e.g. size, shape, state, etc.) due to evaporation, droplet interaction, phase changes, etc. These chemicals pose a difficult problem for low order models as the droplet physics are not well understood and so cannot be adequately modeled. Further, these chemicals are difficult to measure using traditional aerosol sampling techniques due to their caustic nature and the likelihood of changing properties due to physical sampling. Both new techniques to measure the aerosol dynamics and data from controlled experiments are critically needed to develop and validate these computational models. The objectives of the proposed work are to: First develop an optical technique to quantify the aerosol conditions (size, shape, speed, etc.) at a given location in the plume of a large scale atmospheric release; And, second, apply the technique to acquire data that can be used as stand-alone data or in combination with data from other researchers to develop and validate low order models to simulate incidents involving the release of volatile/caustic chemicals. An optical technique (High Magnification Shadow Imaging, HMSI) for measurement of local aerosol dynamics in full scale, full light atmospheric tests will first be developed. Following this the technique will be applied in large scale atmospheric tests to support the development and validation of computational tools.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 26, 2016
- Source ID
- HDTRA11510064
Entities
People
- Douglas Bohl
Organizations
- Clarkson University
- Defense Threat Reduction Agency