Human lung simulants subjected to underwater explosions – An experimental investigation

An experimental investigation was performed on human lung simulants to evaluate their response to an underwater explosive blast. The artificial lungs were instrumented with sensors to record changes in the internal pressure and strains for a specimen with and without a surrounding ribcage. The lungs were to-scale models representative of a 50th-percentile male. The experiments were performed using 65.5 mg of explosive charge placed 0.5 m from the lungs in an 8,200-liter water tank. The tank was instrumented with blast transducers and high-speed cameras to measure the pressure from the explosive charge and record the lung deformation history through high-speed images and digital image correlation. Results showed a significantly delayed response to the underwater blast due to the lungs’ inertia. In addition, the lung response was indifferent to its orientation relative to the shock direction. The lungs initially contracted after the underwater shock and then expanded, showing a 50% change in relative volume, from minimum to maximum volume, over a 7 ms duration. Results and observations qualitatively relate to the types of injuries observed during preexisting case studies.