Experimental study on the propagation of shock wave in the channel with flat wall

To investigate the propagation process of shock waves within a channel under different explosive yields and charge positions, this study established an experimental channel designed for individual soldier transit. Through experiments and simulations, it is found that the quantity and position of the charge affect the time history of overpressure and shock wave parameters. Within the tunnel, the propagation velocity and overpressure peak of the shock wave decreased with increasing of distance, while the duration and impulse of positive overpressure continuously extend and increase. When the charge equivalent increases, all shock wave parameters are enhanced, though the influence on the rate of overpressure peak attenuation is minimal. As the distance between the explosion center and the interior of the tunnel increases, all parameters decline. Both experiments and simulations reveal a unique change in the time history of overpressure and shock wave parameters near the 9 m measurement point inside the tunnel. By analyzing pressure contour maps and overpressure time history, it is discovered that wavefront movement is the primary cause. Based on the fundamental shock wave theory, a higher overpressure peak of shock wave results in faster wavefront motion. From the 3 m to 7 m section inside the entrance, the leading wavefront overpressure continuously attenuates with increasing distance, and its motion speed significantly decreases. However, the overpressure values of subsequent reflected waves attenuate more slowly or even exceed those of the leading wavefront due to continuous collision and superposition. Between the 7 m and 9 m sections inside the entrance, the reflected waves formed by later superposition catch up with and overlap the leading wavefront, resulting in an increase in the first peak value with increasing distance. This process is also clearly understood through the simulated overpressure contour map. Based on the experimental and numerical simulation results, a predictive model for shock wave overpressure within the channel, which has practical engineering reference significance, has been developed.