• TECHNICAL FACILITIES FOR ENSURING SECURITY

    COMPUTATIONAL FLUID DYNAMIC MODEL FOR ESTIMATING DROPLET NUMBER FLOW RATE THROUGH A LASER BEAM

    Security & Future, Vol. 1 (2017), Issue 2, pg(s) 79-82

    The current work is related to improving security by developing a new type of fog sensors and devices. We investigate fogs and their ability to absorb and clean various pollutants from air, including chemical, biological, radiological and nuclear (CBRN) agents. Fog can be used very effectively for counteraction to terrorist attacks and weapons of mass destruction, as well as for prevention of industrial accidents and disasters. It is crucial to study the specific sizes of fog droplets, which optimally collect dangerous substances. We present a computational fluid dynamic model for estimating droplet number flow rate through a laser beam. It shows, that we can make a quantitative assessment of both the number flow rate and the droplet diameter distribution. After we have confirmed that it is possible to monitor these parameters, we proceed and investigate how they are varied, when the laser beam’s distance from the nozzle is changed. Thus, by selecting the distance between the laser beam and the nozzle, it will be possible to measure the diameters and the number of fog droplets. Different nozzles can be simulated easily by entering their output parameters (mass flow rate, diameter distribution, orifice diameter) in the setup.

  • TECHNICAL FACILITIES FOR ENSURING SECURITY

    AEROSOL GENERATION DEVICES SUITABLE FOR SIMULATING FOGS IN LABORATORY CONDITIONS

    Security & Future, Vol. 1 (2017), Issue 1, pg(s) 38-41

    The current work is related to development of sensors for contamination detection, and systems, which use fog as a cleaning agent, in order to prevent disasters and accidents, and to help acting against terrorist attacks and weapons of mass destruction. Investigations in laboratory conditions of several types of mist generators are presented. For this purpose, various products, which create aerosols, were researched. The diameter distributions of the droplets, produced by them, were experimentally determined. For development purposes, several simple devices for easy fog generation are chosen. This study is related to the development of sensors for fog with different characteristics. The obtained results allow a proper selection of sprayers to be made, so that the necessary conditions for the development of sensors are ensured.