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1987
Conference Proceeding
Titel
Constructive means for spike damping. Simulating weapon effects in shock tubes
Alternative
Konstruktive Mittel zur Spike-Dämpfung bei der Simulation von Waffenwirkungen in Stoßrohren
Abstract
When weapon effects are simulated in large shock tubes these tubes must be enlarged more or less abruptly. Then so-called spikes occur in the pressure-time history at any points, which can effect an unwished response of a test-object, not comparable with the real weapon effects. These spikes can be avoided by a long smooth extension from the small diameter to a large one in the driven tube. However not in all cases this can be done especially not in the case of multiple-driver tubes. By experiments constructive means should be investigated to damp or even to eliminate such spikes. A small scaled tube was installed with a scaling factor of 1:63 in comparison with an actually working device. It could be shown that there are several ways to damp the spike; some of which however cannot be recommended, i.e. means like grids or baffles having a strong blocking effect; because they not only damp the spikes but they attenuate also the amplitude of the blastwave to an unacceptable degree. Using perforated tunnels as an inner coating of the expansion tube and special extension parts from small to large diameter a good damping can be achieved. In this presentation the experiments are described, the results discussed and the best means under investigation are proposed. (EMI)