Accurate prediction of the effects of an adjacent wall on the global flow behaviour behind a diffracting shock wave plays a crucial role in describing high speed flow around complex structures. This research studied the near-wall effects on flow patterns behind a diffracting shock wave on curved walls using both numerical and experimental analysis. The development of the three-shock configuration/s and the unsteady development of secondary and recompression shocks were examined. The flow did not separate behind the diffracting shock for incidence shock Mach numbers less than 1.5. A three-shock configuration was observed from incident shock Mach number 1.5 while two three-shock configurations were observed at higher Mach numbers, though the upper three-shock interaction point faded away with time when the Mach number approached 3.0. For the range of incident shock Mach numbers between 1.5 and 2.0 both secondary and recompression shocks existed, however, the secondary shock did not exist at higher Mach numbers and the recompression shock faded away as the diffraction progressed downstream before finally disappearing at a later time.