Design and validation of an experimental set-up to study shock wave propagation in liquid foams

Liquid foams have shown a significant potential in mitigating pressure waves such as acoustic, shock and blast waves. However, the variety of experimental set-ups in the literature makes it difficult to draw definitive conclusions and compare results from one study to another. This variability can often be attributed to the lack of control over foam parameters, with some, such as bubble size, being undocumented or insufficiently detailed. The present study addresses this issue by developing a set-up that precisely controls critical parameters such as bubble size, liquid fraction, wave Mach number and waveform (sustained shock or blast wave). Pressure waves are generated with a shock tube, and their interaction with foams is analysed in a specifically designed and carefully regulated test section. The versatility of this set-up allows for the exploration of a wide range of wave conditions and foam properties. Preliminary results are presented, which validate our set-up design and its ability to control the relevant parameters for studying pressure wave attenuation.