Ingenieurwissenschaften und zugeordnete Tätigkeiten
In the future new types of lift charges for display Shells will enter the market. These types may not be based on black powder and therefore will show different Performance behaviors. The European standard series EN 16261 deals with the testing and assessment of display fireworks in order to satisfy the essential safety requirements which have to be met before placing these items on the EU market.
The aim of the study is to investigate how certain types of lift charges (NC based) influence the lift, tumbling and drift of cylindrical shells. In consequence, if the performance characteristics deviate strongly from those of typical black powder, safety related regulations in the EU and Germany might be affected, as well.
For these investigations, over 50 cylindrical shells were specifically manufactured at BAM to guarantee full influence on all relevant constructional aspects. The shells were constructed to be “blind”, i. e. without break and effect charges, to investigate drift effect on ground in relation to the shooting location. The only reactive substances were the lift charges and a tracer star at the bottom of the shells to guarantee visibility for the post processing using the video grammetric system. The cylindrical shells were of a nominal caliber of 100 mm and manufactured in three different length configurations (single, double and triple length). Their gross weights were designed to correspond to typical effect shells of the same kind. In addition, the impact of different weight distributions inside the shells, leading to altered balance points, on the performance parameters of the shells were also part of this study. Three different types of NC based lift charges were used to show a variety in pressure build ups.