1. Aim Direct impulse measurement for DDT initiation. Calculate impulse from Ballistic pendulum Pressure traces Wave reflection analysis Numerical simulation 2-10-00 California Institute of Technology Graduate Aeronautical Laboratories

2. Ballistic pendulum Pendulum: l = 1.55m M = 12.8kg Tube: L = 1.5m I.D = 38mm Diagnostics: 3 pressure gauges blast gauge video 2-10-00 California Institute of Technology Graduate Aeronautical Laboratories

3. Wave reflection analysis where 2-10-00 California Institute of Technology Graduate Aeronautical Laboratories

4. Pressure integration 2-10-00 California Institute of Technology Graduate Aeronautical Laboratories

5. Preliminary results: Impulse with varying initial pressure (Zitoun R., Gamezo V., and Desbordes D., presented at 2nd International Meeting: Properties of Reactive Fluids and their Applications to Propulsion. LCD, UPR 9028 CNRS, ENSMA, Futuroscope, March 1996) 2-10-00 California Institute of Technology Graduate Aeronautical Laboratories 2-10-00

6. Preliminary results: Impulse with varying equivalence ratio California Institute of Technology Graduate Aeronautical Laboratories 2-10-00

7. Conclusions The problem of determining the impulse delivered by a DDT initiated detonation is being studied in several ways (experimental, theoretical and numerical). A parametric expression for the impulse based on an analysis of the gas dynamics is being investigated. A systematic error occurs between impulse measurements made from the ballistic pendulum and pressure history integration. Effects of: Distance to P1 DDT transition time Other losses experienced by the flow Future Work Investigation of exit geometry. Investigation of the effectiveness of initiation processes. 2-10-00 California Institute of Technology Graduate Aeronautical Laboratories