Mach reflection of a ring shock wave from the axis of symmetry

The paper is devoted to the theoretical and experimental investigation of the ring (toroidal) shock wave near the axis of symmetry. The theoretical approach is based upon the Chester–Chisnell–Whitman method. The experimental toroidal shock wave is generated by a novel inducer and visualized by the shadow technique. Attention is paid to the manner of reflection of the shock wave from the axis of symmetry. This reflection appears to be irregular even at small distances from the centre of the ring. This phenomenon is due to the cumulative acceleration of the converging axisymmetric shock front near the axis. The acceleration results in an increase in the incidence angle up to that characteristic of Mach (irregular) reflection.