The regular and Mach reflections of shock waves from explosions in real air

Abstract

Systematic research was carried out for shock wave reflection problems from an explosion in real air. When shock waves from an explosion on the ground meet with the mountain terrain of positive slope, a single reflection appears. When an aerial explosion above-ground is presented, on basis of the interaction of the incident shock wave with the ground, continuous reflection is produced. If the explosion occurs in a tunnel, due to restriction of the narrow tunnel space, a complicated interaction of shock waves with the walls and reflected shock waves is produced. A calculation of regular and Mach reflection of shock waves from an explosion is conducted with real air state equations. In a regular reflection region, we adopt the variable γ regular reflection theory and the reflectiontermination condition is controlled by the sonic ray angle. In a Mach reflection region, we adopt the Russian scientist Korotkov method to establish the linear analysis solution for a small slope angle and give the start condition for Mach reflection and the limit control condition of Mach reflection for different explosions. Our study leads to a curve diagram showing the relation of ground shock waves’ reflection overpressure and dynamic pressure versus incident overpressure and incident angle.