AFRL Characterizes Airblast of Cased Weapons Published June 7, 2007 By Munitions Directorate AFRL/MN EGLIN AIR FORCE BASE, Fla. -- Airblast characterization is vital to fully understanding the performance capability of any existing or concept munitions. AFRL researchers use an instrumented blastpad to characterize airblast. The instrumented blastpad is unique in its design, with the capacity to measure airblast from cased or uncased test items. Researchers redesigned the blastpad to include an exhaust/blast tunnel, adding the capability to measure airblast in a tunnel environment. AFRL uses airblast characterization data in developing weapons effectiveness prediction software. The purpose of this software is to aid the warfighter's efficient selection of munitions for a specific target. It will also assist the design of future experiments for Air Force and concept munitions. Cased weapons are particularly difficult to characterize because of fragments produced during detonation; these fragments are hazardous to most measurement devices. The instrumented blastpad design, however, has features that essentially eliminate all hazardous fragments that would interfere with data collection, which occurs via 85 flush-mounted pressure transducers. Positioned at varying distances and azimuths, the transducers create a series of concentric circles and semicircles about the item. Each pressure transducer records pressure-time histories, from which researchers can derive the impulse and peak pressures necessary for developing weapons effectiveness prediction software. Used in conjunction with target models of munitions effectiveness, the prediction software improves AF insight, while reducing costly full-scale weapons testing. Ultimately, AFRL's instrumented blastpad will assist in providing warfighters the capability to recognize--during the planning stage of AF strike missions--a munition's relative effectiveness against targets. This will facilitate efficient selection of weapons appropriate for given targets, increasing the probability of successful target engagement throughout the mission, minimizing collateral damage, and decreasing munitions costs.