About the attenuating effect of expansion chambers in channels

The attenuation effect of expansion chambers on the traveling shock waves therein was investigated in a 2d-model scale study. Shock tube experiments were performed visualizing the process with the help of an optical shadow-schlieren technique and a Cranz-Schardin camera and measuring pressures using piezo-electric gages. The evaluation yielded values for the attenuation which were additionally confronted with code computations applying SHARC. The agreement between both types of data is surprisingly well. - It follows that the chamber length influences the attenuation more than its height.